clinical studies case study

Study record managers: refer to the Data Element Definitions if submitting registration or results information.

Search for terms

• Advanced Search
• See Studies by Topic
• See Studies on Map
• How to Search
• How to Use Search Results
• How to Find Results of Studies
• How to Read a Study Record

• Learn About Studies
• Other Sites About Studies
• Glossary of Common Site Terms

• Submit Studies to ClinicalTrials.gov PRS
• Why Should I Register and Submit Results?
• FDAAA 801 and the Final Rule
• How to Apply for a PRS Account
• How to Register Your Study
• How to Edit Your Study Record
• How to Submit Your Results
• Frequently Asked Questions
• Support Materials
• Training Materials

• Selected Publications
• Clinical Alerts and Advisories
• Trends, Charts, and Maps
• Downloading Content for Analysis

• ClinicalTrials.gov Background
• About the Results Database
• History, Policies, and Laws
• ClinicalTrials.gov Modernization
• Media/Press Resources
• Linking to This Site
• Terms and Conditions

ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world.

Explore 489,112 research studies in all 50 states and in 223 countries..

ClinicalTrials.gov is a resource provided by the U.S. National Library of Medicine.

IMPORTANT : Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.

Before participating in a study, talk to your health care provider and learn about the risks and potential benefits .

• Studies by Topic
• Studies on Map

Patients and Families

Researchers, study record managers.

• Customer Support
• Accessibility
• Viewers and Players
• Freedom of Information Act
• HHS Vulnerability Disclosure
• U.S. National Library of Medicine
• U.S. National Institutes of Health
• U.S. Department of Health and Human Services

Have a language expert improve your writing

Run a free plagiarism check in 10 minutes, generate accurate citations for free.

• Knowledge Base

Methodology

• What Is a Case Study? | Definition, Examples & Methods

What Is a Case Study? | Definition, Examples & Methods

Published on May 8, 2019 by Shona McCombes . Revised on November 20, 2023.

A case study is a detailed study of a specific subject, such as a person, group, place, event, organization, or phenomenon. Case studies are commonly used in social, educational, clinical, and business research.

A case study research design usually involves qualitative methods , but quantitative methods are sometimes also used. Case studies are good for describing , comparing, evaluating and understanding different aspects of a research problem .

Table of contents

When to do a case study, step 1: select a case, step 2: build a theoretical framework, step 3: collect your data, step 4: describe and analyze the case, other interesting articles.

A case study is an appropriate research design when you want to gain concrete, contextual, in-depth knowledge about a specific real-world subject. It allows you to explore the key characteristics, meanings, and implications of the case.

Case studies are often a good choice in a thesis or dissertation . They keep your project focused and manageable when you don’t have the time or resources to do large-scale research.

You might use just one complex case study where you explore a single subject in depth, or conduct multiple case studies to compare and illuminate different aspects of your research problem.

Here's why students love Scribbr's proofreading services

Discover proofreading & editing

Once you have developed your problem statement and research questions , you should be ready to choose the specific case that you want to focus on. A good case study should have the potential to:

• Provide new or unexpected insights into the subject
• Challenge or complicate existing assumptions and theories
• Propose practical courses of action to resolve a problem
• Open up new directions for future research

TipIf your research is more practical in nature and aims to simultaneously investigate an issue as you solve it, consider conducting action research instead.

Unlike quantitative or experimental research , a strong case study does not require a random or representative sample. In fact, case studies often deliberately focus on unusual, neglected, or outlying cases which may shed new light on the research problem.

Example of an outlying case studyIn the 1960s the town of Roseto, Pennsylvania was discovered to have extremely low rates of heart disease compared to the US average. It became an important case study for understanding previously neglected causes of heart disease.

However, you can also choose a more common or representative case to exemplify a particular category, experience or phenomenon.

Example of a representative case studyIn the 1920s, two sociologists used Muncie, Indiana as a case study of a typical American city that supposedly exemplified the changing culture of the US at the time.

While case studies focus more on concrete details than general theories, they should usually have some connection with theory in the field. This way the case study is not just an isolated description, but is integrated into existing knowledge about the topic. It might aim to:

• Exemplify a theory by showing how it explains the case under investigation
• Expand on a theory by uncovering new concepts and ideas that need to be incorporated
• Challenge a theory by exploring an outlier case that doesn’t fit with established assumptions

To ensure that your analysis of the case has a solid academic grounding, you should conduct a literature review of sources related to the topic and develop a theoretical framework . This means identifying key concepts and theories to guide your analysis and interpretation.

There are many different research methods you can use to collect data on your subject. Case studies tend to focus on qualitative data using methods such as interviews , observations , and analysis of primary and secondary sources (e.g., newspaper articles, photographs, official records). Sometimes a case study will also collect quantitative data.

Example of a mixed methods case studyFor a case study of a wind farm development in a rural area, you could collect quantitative data on employment rates and business revenue, collect qualitative data on local people’s perceptions and experiences, and analyze local and national media coverage of the development.

The aim is to gain as thorough an understanding as possible of the case and its context.

Prevent plagiarism. Run a free check.

In writing up the case study, you need to bring together all the relevant aspects to give as complete a picture as possible of the subject.

How you report your findings depends on the type of research you are doing. Some case studies are structured like a standard scientific paper or thesis , with separate sections or chapters for the methods , results and discussion .

Others are written in a more narrative style, aiming to explore the case from various angles and analyze its meanings and implications (for example, by using textual analysis or discourse analysis ).

In all cases, though, make sure to give contextual details about the case, connect it back to the literature and theory, and discuss how it fits into wider patterns or debates.

If you want to know more about statistics , methodology , or research bias , make sure to check out some of our other articles with explanations and examples.

• Normal distribution
• Degrees of freedom
• Null hypothesis
• Discourse analysis
• Control groups
• Mixed methods research
• Non-probability sampling
• Quantitative research
• Ecological validity

Research bias

• Rosenthal effect
• Implicit bias
• Cognitive bias
• Selection bias
• Negativity bias
• Status quo bias

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.

McCombes, S. (2023, November 20). What Is a Case Study? | Definition, Examples & Methods. Scribbr. Retrieved April 1, 2024, from https://www.scribbr.com/methodology/case-study/

Is this article helpful?

Shona McCombes

Other students also liked, primary vs. secondary sources | difference & examples, what is a theoretical framework | guide to organizing, what is action research | definition & examples, what is your plagiarism score.

Case Reports Vs Clinical Studies

Uncategorized

This post discusses questions validity if authored by an employee of the reporting company, Roho. This blog will answer these questions regarding clinical studies and clinical evidence:

• What is the difference between a clinical study and a case report?
• Who can observe and document the results of a clinical study?
• What circumstance would beg questioning the validity of a case report?

(Information below was take from the site clinical trials .gov a service of the National Institute of Health)

Definition of case report and clinical study

In medicine, a  case report  is a detailed  report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient.  Case reports  may contain a demographic profile of the patient, but usually describe an unusual or novel occurrence.

The case report is written on one individual patient.

Clinical Study

A research study using human subjects to evaluate biomedical or health-related outcomes. Two types of clinical studies are Interventional Studies  (or clinical trials) and  Observational Studies . A clinical study involves multiple patients.

Observational Clinical Studies have a qualified investigator.

In an observational study, investigators assess health outcomes in groups of participants according to a research plan or protocol. Participants may receive interventions (which can include medical products such as drugs or devices) or procedures as part of their routine medical care, but participants are not assigned to specific interventions by the investigator (as in a clinical trial).

The Key Responsibilities of a Clinical Study Investigator:

• Be qualified to practice medicine or psychiatry and meet the qualifications specified by applicable national regulatory requirements(s)
• Be qualified by education, training, and experience to assume responsibility for the proper conduct of the study,
• Be familiar with and compliant with Good Clinical Practice (GCP)  ICH E6 Guideline  and applicable ethical and regulatory requirements prior to commencement of work on the study.
• Provide evidence of his/her qualification using the Abbreviated  TransCelerate Curriculum Vitae (CV) form

The internal validity of a medical device case report is questioned if bias is present. One must consider bias in a case report authored by an employee of the company that makes the device described in the report.

These are the facts on clinical studies published on the roho website. 

• There are 15 of what roho calls clinical studies on the roho website.  Based on the above definitions, these are not clinical studies but rather case reports. 
• Of these 15 case reports only one pertains a seat cushion improving a pressure ulcer.

This one single case report is written by Cynthia Fleck, an employee of crown therapeutics which is a division of roho

After selling 1 million cushions over the span of 45 years in business roho has exactly 1 case report which was written by an employee of roho which then begs the question of validity of this report.

Related Posts

Pressure Injury Prevention , SofTech , Uncategorized

Considerations with a standing chair mechanism in fighting pressure sores.

Inspirational people in wheelchairs to follow on social media, get relief & healing from pressure injuries.

Order Your Pressure Relief Wheelchair Cushion Today

This site is part of the Informa Connect Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 3099067.

• Informa Connect

Real World Evidence in clinical trials: 3 case studies of successful implementation

Share this article

Real World Evidence in clinical trials offers huge potential to change how studies are run. Today’s advanced technologies such as artificial intelligence platforms, commoditized data collection tools and large integrated healthcare IT infrastructures allow us to go one step further in collecting and utilizing data. However, there are clearly still huge hurdles to full implementation of RWE in clinical trials. Here we look at three case studies of real world evidence being successfully used in clinical trials as well as what data can be used in RWE studies.

Case Study 1: Salford Lung Studies

The innovative Salford Lung Studies are often showcased as great example of an RWE-based study. The GSK sponsored study examined the safety and effectiveness of a new treatment for chronic obstructive pulmonary disease. It involved over 2,802 patients treated by their own GPs in everyday clinical practice. The study had low exclusion criteria: 90% of screened patients were included in the study to replicate a representative sample of everyday practice. The goal of the study was to collect data that reflected medicine taking behaviors and collect valid data with minimal disruption to normal care, while enrolling a large generalizable proportion of eligible population. Deemed a success, 93% of participants remained for the duration of the study, and a number of conclusive clinical results were attained.

RELATED ARTICLE:  Real World Evidence: Revolutionizing the Clinical Trials Environment - WHITEPAPER

Case Study 2: Avelumab approval

Real-world evidence also played a key role in the recent approval of avelumab, a monoclonal antibody used to treat metastatic Merkle cell carcinoma (mMCC), a rare aggressive skin cancer. Since there are no standard of care for mMCC, investigators used data generated data from EHRs on observed clinical outcomes in a patient population that received chemotherapy to establish a benchmark for chemotherapy efficacy in a real-world setting. Researchers identified patients who responded to avelumab, and documented the benefits by contrasting it to the benchmarked data. Last year, the FDA granted accelerated approval to avelumab.

Case Study 3: PatientsLikeMe and amyotrophic lateral sclerosis (ALS)

Data from RWE can also be used to save costs and concentrate clinical studies on more promising candidates. The case of PatientsLikeMe and amyotrophic lateral sclerosis (ALS) is an excellent example. PatientsLike me as an important personalized healthcare network, with a large ALS community. Using its database, researchers found that 9% (348) of patients with ALS in the PatientsLikeMe community reported using lithium carbonate, a drug which had shown promise in a small study (16 treated patients, 28 controls), but which did not have regulatory approval. This created an opportunity to create a larger observational study, using data gathered from these patients, which was matched to multiple control groups. In the end, no difference in disease progression was observed after 12 months between the overall study group and those patients in the lithium carbonate treatment group (78 patients). Subsequent randomized studies reached the same conclusion that there was no clinical effect in the overall population.

Which data can be used in RWE studies?

Not all data is acceptable for RWE-studies. Hence, it is the submitter’s responsibility to show that the data is of sufficient quality. One way to do that is to follow the Hahn framework, which consists of three components:

• Conformance – Does your data conform to specified regulatory standards?
• Completeness – Relates to frequencies of data attributes present in a data set
• Plausibility – Associated to the truthfulness of data

The issues around conformance are crucial, as data submitted to regulatory agencies need to follow the appropriate data standards. As an organization, to be able to work with RWD across multiple sources, data may need to be put into a common format, with common representation (terminologies, vocabularies, coding schemes). The FDA recognizes the importance of developing data standards to maximize the utility of RWD and is working on identifying relevant standards and methodologies for collection and analysis of RWD. Currently, the FDA and EMA both already have a number of guidance documents on the use, sharing and storing of electronic data. They provide recommendations on how to store and capture data and as well on the authenticity and reliability of your data storage. This can include implementing audit trails for electronic records, and how to archive records that are pertinent to clinical investigations.

Completeness has long been seen as a roadblock to REW adoption: critics have long believed that consumers by themselves are likely to submit incomplete data, or likely to forget and / or omit information from their records. This why the FDA require patient registries used in RWE studies have sufficient processes, such as those to gather follow-up information when needed, to ensure data quality, and to minimize missing or incomplete data.

Plausibility focuses on the believability of data. Where the first two criteria focus on the structure of data (conformance) and its presence (completeness), plausibility is uniquely concerned with the actual values being shared. This is another long-standing roadblock to the adoption of RWE, as critics fear that patients would fudge values rather than reporting truthfully due to their own self-interest. The automation of data collection (through wearable devices for example) alleviates this concern, as long as proper guidelines to validate the source and reliability of the data is supplied.

READ MORE:  Real World Evidence: Revolutionizing the Clinical Trials Environment - WHITEPAPER

About the Author: Jean-Francois Denault, MBA has been working with innovators and entrepreneurs in life sciences as a professional consultant for over fifteen years. He has worked with over 50 different clients in life sciences located all over the world. He has written a dozen articles for various publications and is the author of two life sciences marketing handbooks.

Related Articles

Andreas diacon, task applied science, announced as winner of christine pierre lifetime achievement award 2019, pharma’s pivotal role in social determinants of health, related event, clinical trials europe.

• 29 Nov, 2023
• Cologne, Spain

Cookies on GOV.UK

We use some essential cookies to make this website work.

We’d like to set additional cookies to understand how you use GOV.UK, remember your settings and improve government services.

We also use cookies set by other sites to help us deliver content from their services.

You have accepted additional cookies. You can change your cookie settings at any time.

You have rejected additional cookies. You can change your cookie settings at any time.

• Health and social care
• Medicines, medical devices

Agile, responsive regulation helps early breast cancer patients to benefit from a study to potentially improve survival outcomes

Following MHRA approval of a clinical trial, early breast cancer patients on endocrine-based therapy can benefit from a study with camizestrant.

Breast cancer is the most common cancer and is one of the leading causes of cancer-related deaths worldwide.

Data published between 2016 to 2018 suggests that close to 56,000 new cases of breast cancer are diagnosed in the UK, mostly affecting females, and with 86% presenting with early disease.

Most breast cancers have proteins (receptors). These include oestrogen receptor-positive (ER+), where breast cancers have receptors for the hormone oestrogen, and HER2-negative, where the protein is absent – human epidermal growth factor 2.

Hormones, particularly oestrogen, can attach to these receptors and encourage the cells to grow. A pathologist can identify the receptors during biopsy or surgery, helping to determine treatment.

Recent research has led to the development of new candidate drugs known as SERDS (selective oestrogen receptor degraders). These drugs are designed to attach to and disrupt these oestrogen receptors, preventing the growth of cancer.

A new SERD molecular entity, camizestrant, is under clinical development by biopharmaceutical company AstraZeneca and is currently in a Phase III study. The drug candidate is administered orally in the form of a film-coated tablet and acts by targeting oestrogen receptors.

This Phase III open-label study in early breast cancer enrols 5,500 patients worldwide. It aims to assess if camizestrant improves survival outcomes compared to standard adjuvant endocrine-based therapy for patients who are ER-positive and HER2-negative.  

Good practice clinical trials application

The MHRA’s agile regulatory framework for clinical trials supports innovation in the life sciences sector by assessing and approving safe, effective, and efficient trials that benefit patients in the UK and around the world.  

AstraZeneca submitted a compliant application for the clinical study to the MHRA in September 2023. Their cover letter addressed the recommended points of reference for the MHRA assessors, including signposting and highlighting certain areas that have changed, and cross referencing to other studies and guidance.

The company focused on the quality, effectiveness, and safety profile of camizestrant and the other investigational medicinal products relevant to the patient population. The protocol and documents appropriately reflected the risks and mitigation measures, making the task as efficient as possible for the MHRA’s assessors. 

An agile and responsive regulator  

The MHRA’s expert assessors took a risk-proportionate, targeted approach to reviewing the camizestrant clinical trial application. This medicine had already been used in people with cancer, so evidence was available to support the application.

Whilst acknowledging that this study design was simple, the protocol was well written and clearly presented. The agency was adequately assured of the pharmaceutical quality, risk mitigation measures and safety reporting to support a favourable risk/benefit balance for the trial.  

The MHRA issued a decision in 25 calendar days. The final outcome (acceptance) for the study was in 32 days. No grounds for non-acceptance were issued from any MHRA assessors, and the responses from the Research Ethics Committee and Health Research Authority were received promptly.  

Since 1st September 2023, the MHRA has assessed all initial applications within the statutory timeframe of 30 days.

“This continually improving performance in regulatory timescales, along with a holistic national health service, an active academic research community and an ethnically diverse population, makes the UK a globally competitive location for clinical research,” comments Andrea Manfrin, the MHRA’s Deputy Director, Clinical Investigations and Trials.

“Our experts are dedicated and pragmatic in their approach to assessing trials. We are committed to providing predictable and reliable timescales for Clinical Trial Authorisation applications, so that sponsors can plan with confidence their studies in the UK.”

The MHRA receives between 950 and 1,000 clinical trial authorisation (CTA) applications for investigational medicinal products (IMPs) per year, with more than half requiring additional information to be submitted before they are considered approvable.

To assist applicants, the MHRA has published online guidance that identifies common issues with the validation and assessment of clinical trial applications and how to avoid them throughout the process, helping to ensure that clinical trials are assessed efficiently.

Applicants can also ask for scientific advice from the MHRA at any stage of the development of their medicine.

Advice on specific or regulatory aspects of a clinical trial can also be obtained via the agency’s Clinical Trials Helpline at [email protected] .

See Common issues identified during clinical trial applications .

• Study Details - An Adjuvant Endocrine-based Therapy Study of Camizestrant (AZD9833) in ER+/​HER2- Early Breast Cancer (CAMBRIA-2) (CAMBRIA-2)
• Tests on your breast cancer cells
• Facts and figures about breast cancer

About the MHRA

An executive agency of the Department of Health and Social Care (DHSC), the Medicines and Healthcare products Regulatory Agency (MHRA) is responsible for regulating all medicines and medical devices in the UK by ensuring they work and are acceptably safe. All the agency’s work is underpinned by robust and fact-based judgements to ensure that the benefits justify any risks. 

About AstraZeneca

AstraZeneca is a biopharmaceutical company which is focused on the discovery, production, and commercialisation of a range of prescription drugs. It develops products related to therapy areas such as respiratory, cardiovascular, renal, and metabolic diseases, as well as cancer, autoimmune, infection, and neurological diseases.

The company’s product portfolio includes biologics, prescription pharmaceuticals, and vaccines. AstraZeneca sells its products through wholly-owned local marketing companies, distributors, and local representative offices. The company markets its products to primary care and speciality care physicians and operates in Europe, the Americas, Asia, Africa, and Australasia. AstraZeneca is headquartered in Cambridge, Cambridgeshire, the UK.

Is this page useful?

• Yes this page is useful
• No this page is not useful

Help us improve GOV.UK

Don’t include personal or financial information like your National Insurance number or credit card details.

To help us improve GOV.UK, we’d like to know more about your visit today. We’ll send you a link to a feedback form. It will take only 2 minutes to fill in. Don’t worry we won’t send you spam or share your email address with anyone.

Nursing Case Studies with Answers

Explore Nursing Case Studies with Answers and examples in Carepatron's free downloadable PDF. Enhance your nursing knowledge and prepare for exams with practical scenarios.

By Wynona Jugueta on Mar 25, 2024.

Fact Checked by Ericka Pingol.

What is a case study?

A case study in medicine is a detailed report of a patient's experience with a disease, treatment, or condition. It typically includes the patient's medical history, symptoms, diagnostic tests, treatment course, and outcome.

Some key things to know about medical case studies template . First, they delve deep into the specifics of a single case, providing a rich understanding of a particular medical situation.

Medical professionals use case studies to learn about rare diseases, unusual presentations of common conditions, and the decision-making process involved in complex cases.

Case studies can identify exciting areas for further investigation through more rigorous clinical trials. While informative, they can't be used to develop general treatment guidelines because they only focus on a single case.

Overall, medical case studies are valuable tools for medical education and research, offering insights into human health and disease complexities.

Printable Nursing Case Studies with Answers

Download this Nursing Case Studies with Answers to analyze complex clinical situations, identify priority needs, and develop effective care plans tailored to individual patients.

What is in a nursing case study?

A nursing case study is a detailed examination of a patient's health condition, treatment plan, and overall care journey, specifically from the perspective of nursing practice. These case studies are essential components of nursing education and professional development, providing valuable insights into clinical scenarios and patient care experiences.

In a case nursing study template , various elements are typically included to comprehensively understand the patient's situation. First and foremost, the case study outlines the patient's demographic information, including age, gender, medical history, and presenting symptoms. This demographic overview sets the stage for understanding the context in which healthcare interventions occur.

Moreover, nursing case studies often delve into the nursing assessment process, highlighting the initial and ongoing assessments nurses conduct to gather relevant patient health status data. These assessments involve physical examinations, vital sign monitoring, and assessment tools to identify potential health issues and risk factors.

Critical thinking skills are essential in nursing case studies, as they enable nurses to analyze complex clinical situations, identify priority needs, and develop effective care plans tailored to individual patients. Nursing students and experienced nurses use case studies as opportunities to enhance their critical thinking abilities and clinical decision-making processes.

Nursing case studies serve several vital purposes within healthcare education and professional practice, whether they are a primary care physician or a group of nursing students. Let's explore each purpose in detail:

Enhancing clinical reasoning skills

One primary purpose of nursing case studies is to enhance nursing students' and practicing nurses' clinical reasoning skills. By presenting realistic patient scenarios, case studies challenge individuals to analyze clinical data, interpret findings, and develop appropriate nursing interventions. This process promotes critical thinking and problem-solving abilities essential for effective nursing practice.

Applying theoretical knowledge to practice

Nursing case studies provide a bridge between theoretical knowledge and practical application. They allow nursing students to apply concepts learned in the classroom to real-world patient care situations. By engaging with case studies, students can integrate theoretical principles with clinical practice, gaining a deeper understanding of nursing concepts and their relevance to patient care.

Facilitating interdisciplinary collaboration

Another purpose of nursing case studies is to facilitate interdisciplinary collaboration among healthcare professionals. Nurses often collaborate with physicians, specialists, therapists, and other team members in complex patient cases to deliver comprehensive care. Case studies offer opportunities for nurses to explore collaborative decision-making processes, communication strategies, and teamwork dynamics essential for providing quality patient care.

Promoting evidence-based practice

Nursing case studies are crucial in promoting evidence-based practice (EBP) within nursing and healthcare settings. Nurses can make informed decisions about patient care interventions by analyzing patient scenarios and considering current research evidence. Case studies encourage nurses to critically evaluate research findings, clinical guidelines, and best practices to ensure the delivery of safe, effective, and patient-centered care.

Fostering professional development

Engaging with nursing case studies contributes to the ongoing professional development of nurses at all stages of their careers. For nursing students, case studies provide valuable learning experiences that help prepare them for clinical practice. For experienced nurses, case studies offer opportunities to refine clinical skills, stay updated on emerging healthcare trends, and reflect on past experiences to improve future practice.

How to write a nursing case study?

Writing a nursing case study involves several essential steps to ensure accuracy, relevance, and clarity. Let's break down the process into actionable steps:

Step 1: Select a patient case

Begin by selecting a patient case that presents a relevant and compelling healthcare scenario. Consider factors such as the patient's demographic information, medical history, presenting symptoms (e.g., joint stiffness, pain), and healthcare needs (e.g., medication administration, vital signs monitoring). Choose a case that aligns with your learning objectives and offers meaningful analysis and discussion opportunities.

Step 2: Gather relevant data

Collect comprehensive data about the selected patient case, including medical records, test results, nursing assessments, and relevant healthcare documentation. Pay close attention to details such as the patient's current health status, past medical history (e.g., diabetes), treatment plans, and any ongoing concerns or challenges. Utilize assessment tools and techniques to evaluate the patient's condition thoroughly and identify areas of clinical significance.

Step 3: Assess the patient's needs

Based on the gathered data, evaluate the patient's needs, considering physical, emotional, social, and environmental factors. Assess the patient's pain levels, mobility, vital signs, and other relevant health indicators. Identify any potential complications, risks, or areas requiring immediate attention. Consider the patient's preferences, cultural background, and individualized care requirements in your assessment.

Step 4: Formulate nursing diagnoses

Formulate nursing diagnoses that accurately reflect the patient's health needs and priorities based on your assessment findings. Identify actual and potential nursing diagnoses related to the patient's condition, considering factors such as impaired mobility, ineffective pain management, medication adherence issues, and self-care deficits. Ensure your nursing diagnoses are specific, measurable, achievable, relevant, and time-bound (SMART).

Step 5: Develop a care plan

Develop a comprehensive care plan outlining the nursing interventions and strategies to address the patient's identified needs and nursing diagnoses. Prioritize interventions based on the patient's condition, preferences, and care goals. Include evidence-based nursing interventions to promote optimal health outcomes, manage symptoms, prevent complications, and enhance the patient's overall well-being. Collaborate with other healthcare professionals as needed to ensure coordinated care delivery.

Step 6: Implement and evaluate interventions

Implement the nursing interventions outlined in the care plan while closely monitoring the patient's response to treatment. Administer medications, provide patient education, perform nursing procedures, and coordinate care activities to effectively meet the patient's needs. Continuously evaluate the effectiveness of interventions, reassessing the patient's condition and adjusting the care plan as necessary. Document all interventions, observations, and outcomes accurately and comprehensively.

Step 7: Reflect and seek assistance

Reflect on the nursing case study process, considering what worked well, areas for improvement, and lessons learned. Seek assistance from nursing instructors, preceptors, or colleagues if you encounter challenges or have concerns about the patient's care. Collaborate with interdisciplinary team members to address complex patient issues and ensure holistic care delivery. Continuously strive to enhance your nursing practice through ongoing learning and professional development.

Nursing Case Studies with Answers example (sample)

Below is an example of a nursing case study sample created by the Carepatron team. This sample illustrates a structured framework for documenting patient cases, outlining nursing interventions, and providing corresponding answers to guide learners through the analysis process. Feel free to download the PDF and use it as a reference when formulating your own nursing case studies.

Download this free Nursing Case Studies with Answers PDF example here 

Why use Carepatron as your nursing software?

Carepatron stands out as a comprehensive and reliable solution for nursing professionals seeking efficient and streamlined workflows in their practice. With a range of features tailored to the needs of nurses and healthcare teams, Carepatron offers unparalleled support and functionality for managing various aspects of patient care.

Nurse scheduling software

One of the key advantages of Carepatron is its nurse scheduling software , which simplifies the process of creating and managing schedules for nursing staff. With intuitive scheduling tools and customizable options, nurses can easily coordinate shifts, manage availability, and ensure adequate staffing levels to meet patient needs effectively.

Telehealth platform

In addition, Carepatron offers a robust telehealth platform that facilitates remote patient monitoring, virtual consultations, and telemedicine services. This feature enables nurses to provide continuity of care beyond traditional healthcare settings, reaching patients in remote areas or those unable to attend in-person appointments.

Clinical documentation software

Furthermore, Carepatron's clinical documentation software streamlines the documentation process, allowing nurses to easily capture patient data, record assessments, and document interventions. The platform supports accurate and efficient documentation practices, ensuring compliance with regulatory standards and promoting continuity of care across healthcare settings.

Commonly asked questions

In clinical terms, a case study is a detailed examination of a patient's medical history, symptoms, diagnosis, treatment, and outcomes, typically used for educational or research purposes.

Case studies are essential in nursing as they provide real-life scenarios for nurses to apply theoretical knowledge, enhance critical thinking skills, and develop practical clinical reasoning and decision-making abilities.

Case studies in nursing education offer benefits such as promoting active learning, encouraging problem-solving skills, facilitating interdisciplinary collaboration, and fostering a deeper understanding of complex healthcare situations.

Related Templates

Popular templates.

Chronic Illnesses List

Access this helpful guide on chronic illnesses you can refer to when working on prevention, diagnosis, and treatment planning.

Therapy Letter for Court

Explore our guide on writing Therapy Letters for Court, offering templates and insights for therapists to support clients' legal cases effectively.

Nursing Nutrition Assessment

Learn about nursing nutrition assessments, including examples and Carepatron's free PDF download to help you understand the process and improve patient care.

Facial Massage Techniques PDF

Unlock the secrets of rejuvenating facial massage techniques with Carepatron's comprehensive PDF guide. Learn how to enhance your skincare routine and achieve a radiant, glowing complexion.

Blood Test for Heart Attack

Learn about the importance of blood tests for detecting heart attacks and download Carepatron's free PDF example for reference. Find crucial information to help you understand the process.

Mental Health Handout

Learn key insights into mental health conditions, warning signs, and resources. Access a free Mental Health Handout today!

Procedure Note Template

Ensure patient identity, consent, anesthesia, vital signs, and complications are documented. Download our accessible Procedure Note Template today!

Nursing Home Report Sheet

Discover a comprehensive guide on creating a Nursing Home Report Sheet. Includes tips, examples, and a free PDF download to streamline healthcare reporting.

Obesity Chart

Explore our free Obesity Chart and example, designed to help practitioners and patients monitor overall health risks associated with obesity.

Charge Nurse Duties Checklist

Take charge with our comprehensive Charge Nurse Duties Checklist. Free PDF download available!

Pre-employment Medical Exam

Ensure job applicants' fitness for duty with our Pre-Employment Medical Exam Template. Comprehensive guide for thorough health assessments.

Medical Clearance Form

Get your health clearance certificate easily with our Medical Clearance Form. Download for free for a streamlined process and hassle-free experience.

Level of Care Assessment

Discover what a Level of Care Assessment entails and access Carepatron's free PDF download with an example to help you better understand the process.

Standard Intake Questionnaire Template

Access a standard intake questionnaire tool to help you enhance the initial touchpoint with patients in their healthcare process.

Patient Workup Template

Optimize patient care with our comprehensive Patient Workup Template. Streamline assessments and treatment plans efficiently.

Stroke Treatment Guidelines

Explore evidence-based Stroke Treatment Guidelines for effective care. Expert recommendations to optimize stroke management.

Counseling Theories Comparison Chart

Explore a tool to differentiate counseling theories and select approaches that can work best for each unique client.

Nursing Registration Form

Learn what a nurse registry entails, its significance to registered nurses, and the application process completed through a Nursing Registration Form.

Physical Therapy Plan of Care

Download Carepatron's free PDF example of a comprehensive Physical Therapy Plan of Care. Learn how to create an effective treatment plan to optimize patient outcomes.

ABA Intake Form

Access a free PDF template of an ABA Intake Form to improve your initial touchpoint in the therapeutic process.

Speech Language Pathology Evaluation Report

Get Carepatron's free PDF download of a Speech Language Pathology Evaluation Report example to track therapy progress and communicate with team members.

Home Remedies for Common Diseases PDF

Explore natural and effective Home Remedies for Common Diseases with our guide, and educate patients and caretakers to manage ailments safely at home.

HIPAA Policy Template

Get a comprehensive HIPAA policy template with examples. Ensure compliance, protect patient privacy, and secure health information. Free PDF download available.

Health Appraisal Form

Download a free Health Appraisal Form for young patients. Streamline your clinical documentation with our PDF template and example.

Consent to Treat Form for Adults

Discover the importance of the Consent to Treat Form for adults with our comprehensive guide and example. Get your free PDF download today!

Nursing Skills Assessment

Know how to evaluate nursing skills and competencies with our comprehensive guide. Includes an example template for a Nursing Skills Assessment. Free PDF download available.

Medical Record Request Form Template

Discover how to streamline medical record requests with our free template & example. Ensure efficient, compliant processing. Download your PDF today.

Personal Training Questionnaire

Access a comprehensive Personal Training Questionnaire to integrate when onboarding new clients to ensure a personalized fitness plan.

Agoraphobia DSM 5 Criteria

Explore a helpful documentation tool to help screen for the symptoms of agoraphobia among clients. Download a free PDF resource here.

Dental Inventory List

Streamline your dental practice's inventory management with our Dental Inventory List & Example, available for free PDF download.

Personal Trainer Intake Form

Discover how to create an effective Personal Trainer Intake Form with our comprehensive guide & free PDF example. Streamline your fitness assessments now.

Healthy Liver Foods List

Explore our Healthy Liver Foods List to support liver health with the right diet. Learn how Carepatron aids healthcare professionals in managing nutrition plans.

Printable Family History Form

Streamline patient intake with our Family History Form template. Capture essential family medical history to enhance patient care and risk assessment.

Portable Medication List

Keep track of your prescription medicines, supplements, and vitamins with our Portable Medication List and take care of your health

Universal Health Form

Learn the importance of a Universal Health Form. Download a free PDF and template to guide parents and guardians when completing the form.

Skin Analysis Form

Need a skin analysis form? Download Carepatron's free PDF template and get an example to help you conduct comprehensive skin analyses effectively.

Family Nursing Care Plan

Discover our Family Nursing Care Plan template, designed to help create comprehensive care plans for families and enhance overall well-being.

Client Questionnaire Template

Efficiently gather medical client information with our concise Client Questionnaire Template designed for healthcare professionals. Download now!

Healthcare Practitioner Form

Get Carepatron's free PDF download of a healthcare practitioner form and an example to streamline administrative tasks. Perfect for healthcare professionals looking to improve efficiency.

MOST Medical Form

Discover the essential guide to the MOST Medical Form, including a comprehensive overview and a free PDF example. Ideal for healthcare professionals and users.

Home Care Form

Optimize your healthcare with our Home Care Form, ensuring streamlined processes and personalized care. Improve efficiency today!

Dental Medical Clearance Form

Learn how a Dental Medical Clearance Form works. Download a free PDF template and sample for your practice.

Blood Test for Depression

Learn about blood tests for depression and download Carepatron's free example in PDF format to understand the process better.

Preparticipation Physical Evaluation Form

Download a free Preparticipation Physical Evaluation Form and an example. Streamline your practice documentation with Carepatron's customizable template.

Foot Stress Fracture Test

Learn how to perform the Foot Stress Fracture Test. Download a free PDF template to document your findings and notes.

ADA Blood Sugar Log

Learn about the ADA Blood Sugar Log and how it helps manage diabetes. Download a free PDF and sample here.

Nursing assessment for pneumonia

Learn the importance of nursing assessments in managing pneumonia. Get a free PDF Nursing Assessment for Pneumonia form here.

Vertigo Test

Assess for vertigo with our comprehensive Vertigo Test. Quick, accurate evaluation for symptoms like dizziness and balance issues.

Circulation Assessment

Learn about the circulatory system, its significance, and how to conduct a comprehensive Circulation Assessment using our free template example.

Vitamin Chart

Discover the importance of vitamins for optimal health with our comprehensive Vitamin Chart. Learn about functions, sources, and dietary recommendations.

Medical Needs Form

Download Carepatron's free PDF example of a Medical Needs Form to help organize and track important medical information for individuals. Keep your medical needs organized with this helpful form.

Conduct Disorder Test

Assessing conduct disorder in individuals is crucial for effective intervention. Download Carepatron's free PDF example of a Conduct Disorder Test and learn how to use it effectively.

Women's Daily Nutritional Requirements Chart

Download Carepatron's free PDF chart outlining women's daily nutritional requirements, including examples of a balanced diet to help you meet your dietary needs effectively.

Maximum Heart Rate Chart

Maximize your fitness routine with our Maximum Heart Rate Chart template. Use it to monitor your heart rate and enhance your workout effectiveness safely!

Immunization Form

Streamline school health compliance with our Immunization Form template, designed to track student vaccinations and ensure a safe learning environment.

Work Physical Form

Enhance workplace safety and compliance with our Work Physical Form template, designed for healthcare professionals to assess employee fitness for work.

Nurse Practitioner Collaborative Agreement Template

Streamline nurse practice collaboration with our template—clear agreements for seamless teamwork in healthcare. Download now!

Orthorexia Test

Assess your relationship with food and well-being with our Orthorexia Test. Download the template now for a balanced approach to nutrition.

Home Health Documentation

Download our free Home Health Documentation template to help you with your document needs. Learn the importance of good home health documentation.

Medical Prior Authorization Form

Learn the importance of prior authorization for your patients. Download a free Medical Prior Authorization Form to simply insurance requests.

Daycare Physical Form

Learn the importance of physical exams for daycare. Download a free Daycare Physical Form to document a child's health records.

Psychology Career Test

Take this test to determine your suitability in the role of a psychologist. Use this template as a self test or with clients considering new occupational roles.

Time Lapse Assessment

Download our Time Lapse Assessments for holistic patient care. Learn how tracking changes over time enhances early intervention and personalized treatment plans.

EMT Practice Scenarios

Discover EMT practice scenarios that can support your emergency staff to refine their skills and knowledge as well as enhance their practical skills.

Inpatient Billing Cheat Sheet

Unlock efficient inpatient billing with our Cheat Sheet. Streamline CPT coding, enhance accuracy, and ensure timely reimbursements. Download now!

Pregnancy Verification Letter

Get your pregnancy confirmed with our Pregnancy Verification Letter. Official proof of pregnancy with physician validation simplified!

Normative Test

Discover the essence of normative testing in a concise guide exploring its principles, significance, and applications.

Hearing Test Frequency

Prioritize your hearing health today! Download our free Hearing Test Frequency example for personalized recommendations on monitoring your auditory well-being.

Pancreas Blood Test

Learn more about the Pancreas Blood Test and obtain a template you can use to request and record the results of this assessment.

Neuro Eye Exam

A neuro eye exam is a comprehensive assessment of the visual system to diagnose and manage neurological conditions. Download Carepatron's neuro eye exam PDF to learn more about it.

Discover how to diagnose and manage Small Intestinal Bacterial Overgrowth with our comprehensive SIBO Test Template, designed for healthcare professionals.

Diagnosis Template

Unlock streamlined diagnosis with our template. Ideal for healthcare pros seeking accurate patient assessments. Download now for comprehensive care.

Medicare Private Contract

Explore Medicare Private Contracts: key agreements for medical practitioners opting out of Medicare, ensuring clarity & compliance.

Chiropractic Business Plan

Our Chiropractic Business Plan guide is designed to help you navigate the competitive landscape, optimize operations, and maximize profitability in your chiropractic practice.

Urgent Care Form

Streamline patient check-in and expedite care with our Urgent Care Form template, designed to efficiently gather vital patient information.

Discover the key aspects of an ENT Exam with our comprehensive template, designed for health professionals to assess ear, nose, and throat health effectively.

Home Safety Assessment

Ensure a safer home environment with our comprehensive Home Safety Assessment. Identify potential hazards and take proactive steps for peace of mind.

Dysphagia Care Plan

Optimize patient outcomes with our free Dysphagia Care Plan template. Streamline care delivery for individuals with swallowing difficulties.

Community Health Improvement Plan

Discover how Community Health Improvement Plans (CHIPs) address community health needs strategically for effective outcomes and better population health.

Assess dysphagia with EAT-10: 10-question tool, which predicts aspiration and risk factors and evaluates swallowing disorders. Streamline care and improve outcomes.

Pediatric Assessment

Learn the essentials of pediatric assessment with Carepatron's free PDF download. Get examples and practical guidance for assessing pediatric patients to enhance your skills and knowledge.

Patient Discharge Form

Access a free Patient Discharge Form for easy clinical documentation. Download the PDF template and example now!

Nutrition SOAP Note

Get our free Nutrition SOAP Notes template now! Optimize your nutrition practice with structured documentation. Download here!

Randot Test

Discover the Randot Test and understand how it evaluates stereopsis, suitable age groups, conditions diagnosed, accuracy, and alternatives.

9-Panel Drug Test

Discover the comprehensive 9-panel drug test that screens 9 substances, including marijuana & cocaine. Learn more!

Caregiver Note Template

Access our comprehensive Caregiver Note Template for organized healthcare documentation. Simplify caregiving with our efficient solution.

South Oaks Gambling Screen

Explore the South Oaks Gambling Screen (SOGS) for identifying gambling disorders. Designed for diagnosing and managing gambling-related issues.

Microblading Consent Form

Discover the essential Microblading Consent Form for healthcare professionals and aestheticians, ensuring informed consent and legal compliance.

Medical Consent Form

Get access to a free Medical Consent Form template. Learn its importance in upholding your patients' rights.

Unlock precise and effective EM coding with our free template. Streamline documentation, select accurate codes, and ensure proper reimbursement. Download now!

Patient Follow Up Template

Streamline patient follow-up with our template. Schedule appointments, update medical history, and ensure continuity of care effortlessly!

Nutrition Care Plan

Developing a nutrition care plan is crucial for individuals to improve their health and well-being. Download Carepatron's free nutrition care plan PDF example here.

Diabetes Teaching Plan

Here's a comprehensive Diabetes Teaching Plan with essential blood sugar management information, diabetes education, and patient outcomes. Download now!

General Survey Nursing

Access Carepatron's free PDF download of a General Survey Nursing example to help you understand and improve your nursing assessment skills.

Emergency Nursing Assessment

Learn about the role of emergency nurses and the importance of conducting assessments. Download a free Emergency Nursing Assessment template today!

Otoscope Examination

Learn how to perform an otoscope examination and see an example with our Carepatron's free PDF download.

Ultrasound Test

Are you looking for examples of ultrasound tests? Download Carepatron's free PDF with sample ultrasound test questions to help you prepare for your upcoming exam.

Private Practice Startup Checklist

Launch your practice quickly using our comprehensive Private Practice Startup Checklist. Download for free!

Gallbladder Physical Exam

Learn about the physical exam for the gallbladder, including techniques and examples. Download Carepatron's free gallbladder physical exam PDF guide for reference.

Refusal Skills Worksheet

Develop assertive communication and decision-making with our Refusal Skills Worksheet. Practice strategies to navigate peer pressure and prioritize well-being.

Join 10,000+ teams using Carepatron to be more productive

Folgen Sie uns:

• Umzug in Wien | Privat
• Firmenumzug Wien / Büroumzug
• Verpackungsmaterial
• Küchenmontage Wien
• Möbelmontage Wien
• Räumung Wien
• Entsorgung Wien
• Klaviertransport Wien
• Auslandsumzug
• Umzug Wien nach Niederösterreich
• Umzug Wien Burgenland
• Umzug Wien Baden
• Umzug Wien St. Pölten
• Umzug Wiener Neustadt
• Umzug Wien Vorarlberg
• Umzug Wien Salzburg
• Umzug Wien Innsbruck – Die besten Tipps 2023
• Umzug Wien Deutschland
• Umzug Wien München
• Umzug Wien Berlin

Umzugsfirma Wien: Umzugsservice, schnell & günstig

Umzug Anfrage

Berechnung / besichtigung.

Umzugsfirma Wien - Die Vorteile:

Der allumfassende umzugsservice.

Planen Sie bald einen Umzug? Wir unterstützen Sie gerne dabei!

Unsere garantie bei jeder übersiedlung:.

Zufriedene Kunden sind unsere grösste Priorität.

Die neuesten Bewertungen  von echten Kunden:

Unsere Firmenkunden

Oft gestellte Fragen - FAQ

Wie lange dauert ein umzug, was kostet umzug in wien oder in österreich, klaviertransport oder pianotransport in wien, was kostet ein  umzug innerhalb österreich, neueste artikel im umzug-blog, umzug wien anfrage – 8 wichtige faktoren, was kostet ein umzug in wien, wie erkenne ich eine seriöse umzugsfirma.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• Pediatr Investig
• v.3(4); 2019 Dec

Clinical research study designs: The essentials

Ambika g. chidambaram.

1 Children's Hospital of Philadelphia, Philadelphia Pennsylvania, USA

Maureen Josephson

In clinical research, our aim is to design a study which would be able to derive a valid and meaningful scientific conclusion using appropriate statistical methods. The conclusions derived from a research study can either improve health care or result in inadvertent harm to patients. Hence, this requires a well‐designed clinical research study that rests on a strong foundation of a detailed methodology and governed by ethical clinical principles. The purpose of this review is to provide the readers an overview of the basic study designs and its applicability in clinical research.

Introduction

In clinical research, our aim is to design a study, which would be able to derive a valid and meaningful scientific conclusion using appropriate statistical methods that can be translated to the “real world” setting. 1 Before choosing a study design, one must establish aims and objectives of the study, and choose an appropriate target population that is most representative of the population being studied. The conclusions derived from a research study can either improve health care or result in inadvertent harm to patients. Hence, this requires a well‐designed clinical research study that rests on a strong foundation of a detailed methodology and is governed by ethical principles. 2

From an epidemiological standpoint, there are two major types of clinical study designs, observational and experimental. 3 Observational studies are hypothesis‐generating studies, and they can be further divided into descriptive and analytic. Descriptive observational studies provide a description of the exposure and/or the outcome, and analytic observational studies provide a measurement of the association between the exposure and the outcome. Experimental studies, on the other hand, are hypothesis testing studies. It involves an intervention that tests the association between the exposure and outcome. Each study design is different, and so it would be important to choose a design that would most appropriately answer the question in mind and provide the most valuable information. We will be reviewing each study design in detail (Figure  1 ).

Overview of clinical research study designs

Observational study designs

Observational studies ask the following questions: what, who, where and when. There are many study designs that fall under the umbrella of descriptive study designs, and they include, case reports, case series, ecologic study, cross‐sectional study, cohort study and case‐control study (Figure  2 ).

Classification of observational study designs

Case reports and case series

Every now and then during clinical practice, we come across a case that is atypical or ‘out of the norm’ type of clinical presentation. This atypical presentation is usually described as case reports which provides a detailed and comprehensive description of the case. 4 It is one of the earliest forms of research and provides an opportunity for the investigator to describe the observations that make a case unique. There are no inferences obtained and therefore cannot be generalized to the population which is a limitation. Most often than not, a series of case reports make a case series which is an atypical presentation found in a group of patients. This in turn poses the question for a new disease entity and further queries the investigator to look into mechanistic investigative opportunities to further explore. However, in a case series, the cases are not compared to subjects without the manifestations and therefore it cannot determine which factors in the description are unique to the new disease entity.

Ecologic study

Ecological studies are observational studies that provide a description of population group characteristics. That is, it describes characteristics to all individuals within a group. For example, Prentice et al 5 measured incidence of breast cancer and per capita intake of dietary fat, and found a correlation that higher per capita intake of dietary fat was associated with an increased incidence of breast cancer. But the study does not conclude specifically which subjects with breast cancer had a higher dietary intake of fat. Thus, one of the limitations with ecologic study designs is that the characteristics are attributed to the whole group and so the individual characteristics are unknown.

Cross‐sectional study

Cross‐sectional studies are study designs used to evaluate an association between an exposure and outcome at the same time. It can be classified under either descriptive or analytic, and therefore depends on the question being answered by the investigator. Since, cross‐sectional studies are designed to collect information at the same point of time, this provides an opportunity to measure prevalence of the exposure or the outcome. For example, a cross‐sectional study design was adopted to estimate the global need for palliative care for children based on representative sample of countries from all regions of the world and all World Bank income groups. 6 The limitation of cross‐sectional study design is that temporal association cannot be established as the information is collected at the same point of time. If a study involves a questionnaire, then the investigator can ask questions to onset of symptoms or risk factors in relation to onset of disease. This would help in obtaining a temporal sequence between the exposure and outcome. 7

Case‐control study

Case‐control studies are study designs that compare two groups, such as the subjects with disease (cases) to the subjects without disease (controls), and to look for differences in risk factors. 8 This study is used to study risk factors or etiologies for a disease, especially if the disease is rare. Thus, case‐control studies can also be hypothesis testing studies and therefore can suggest a causal relationship but cannot prove. It is less expensive and less time‐consuming than cohort studies (described in section “Cohort study”). An example of a case‐control study was performed in Pakistan evaluating the risk factors for neonatal tetanus. They retrospectively reviewed a defined cohort for cases with and without neonatal tetanus. 9 They found a strong association of the application of ghee (clarified butter) as a risk factor for neonatal tetanus. Although this suggests a causal relationship, cause cannot be proven by this methodology (Figure  3 ).

Case‐control study design

One of the limitations of case‐control studies is that they cannot estimate prevalence of a disease accurately as a proportion of cases and controls are studied at a time. Case‐control studies are also prone to biases such as recall bias, as the subjects are providing information based on their memory. Hence, the subjects with disease are likely to remember the presence of risk factors compared to the subjects without disease.

One of the aspects that is often overlooked is the selection of cases and controls. It is important to select the cases and controls appropriately to obtain a meaningful and scientifically sound conclusion and this can be achieved by implementing matching. Matching is defined by Gordis et al as ‘the process of selecting the controls so that they are similar to the cases in certain characteristics such as age, race, sex, socioeconomic status and occupation’ 7 This would help identify risk factors or probable etiologies that are not due to differences between the cases and controls.

Cohort study

Cohort studies are study designs that compare two groups, such as the subjects with exposure/risk factor to the subjects without exposure/risk factor, for differences in incidence of outcome/disease. Most often, cohort study designs are used to study outcome(s) from a single exposure/risk factor. Thus, cohort studies can also be hypothesis testing studies and can infer and interpret a causal relationship between an exposure and a proposed outcome, but cannot establish it (Figure  4 ).

Cohort study design

Cohort studies can be classified as prospective and retrospective. 7 Prospective cohort studies follow subjects from presence of risk factors/exposure to development of disease/outcome. This could take up to years before development of disease/outcome, and therefore is time consuming and expensive. On the other hand, retrospective cohort studies identify a population with and without the risk factor/exposure based on past records and then assess if they had developed the disease/outcome at the time of study. Thus, the study design for prospective and retrospective cohort studies are similar as we are comparing populations with and without exposure/risk factor to development of outcome/disease.

Cohort studies are typically chosen as a study design when the suspected exposure is known and rare, and the incidence of disease/outcome in the exposure group is suspected to be high. The choice between prospective and retrospective cohort study design would depend on the accuracy and reliability of the past records regarding the exposure/risk factor.

Some of the biases observed with cohort studies include selection bias and information bias. Some individuals who have the exposure may refuse to participate in the study or would be lost to follow‐up, and in those instances, it becomes difficult to interpret the association between an exposure and outcome. Also, if the information is inaccurate when past records are used to evaluate for exposure status, then again, the association between the exposure and outcome becomes difficult to interpret.

Case‐control studies based within a defined cohort

Case‐control studies based within a defined cohort is a form of study design that combines some of the features of a cohort study design and a case‐control study design. When a defined cohort is embedded in a case‐control study design, all the baseline information collected before the onset of disease like interviews, surveys, blood or urine specimens, then the cohort is followed onset of disease. One of the advantages of following the above design is that it eliminates recall bias as the information regarding risk factors is collected before onset of disease. Case‐control studies based within a defined cohort can be further classified into two types: Nested case‐control study and Case‐cohort study.

Nested case‐control study

A nested case‐control study consists of defining a cohort with suspected risk factors and assigning a control within a cohort to the subject who develops the disease. 10 Over a period, cases and controls are identified and followed as per the investigator's protocol. Hence, the case and control are matched on calendar time and length of follow‐up. When this study design is implemented, it is possible for the control that was selected early in the study to develop the disease and become a case in the latter part of the study.

Case‐cohort Study

A case‐cohort study is similar to a nested case‐control study except that there is a defined sub‐cohort which forms the groups of individuals without the disease (control), and the cases are not matched on calendar time or length of follow‐up with the control. 11 With these modifications, it is possible to compare different disease groups with the same sub‐cohort group of controls and eliminates matching between the case and control. However, these differences will need to be accounted during analysis of results.

Experimental study design

The basic concept of experimental study design is to study the effect of an intervention. In this study design, the risk factor/exposure of interest/treatment is controlled by the investigator. Therefore, these are hypothesis testing studies and can provide the most convincing demonstration of evidence for causality. As a result, the design of the study requires meticulous planning and resources to provide an accurate result.

The experimental study design can be classified into 2 groups, that is, controlled (with comparison) and uncontrolled (without comparison). 1 In the group without controls, the outcome is directly attributed to the treatment received in one group. This fails to prove if the outcome was truly due to the intervention implemented or due to chance. This can be avoided if a controlled study design is chosen which includes a group that does not receive the intervention (control group) and a group that receives the intervention (intervention/experiment group), and therefore provide a more accurate and valid conclusion.

Experimental study designs can be divided into 3 broad categories: clinical trial, community trial, field trial. The specifics of each study design are explained below (Figure  5 ).

Experimental study designs

Clinical trial

Clinical trials are also known as therapeutic trials, which involve subjects with disease and are placed in different treatment groups. It is considered a gold standard approach for epidemiological research. One of the earliest clinical trial studies was performed by James Lind et al in 1747 on sailors with scurvy. 12 Lind divided twelve scorbutic sailors into six groups of two. Each group received the same diet, in addition to a quart of cider (group 1), twenty‐five drops of elixir of vitriol which is sulfuric acid (group 2), two spoonfuls of vinegar (group 3), half a pint of seawater (group 4), two oranges and one lemon (group 5), and a spicy paste plus a drink of barley water (group 6). The group who ate two oranges and one lemon had shown the most sudden and visible clinical effects and were taken back at the end of 6 days as being fit for duty. During Lind's time, this was not accepted but was shown to have similar results when repeated 47 years later in an entire fleet of ships. Based on the above results, in 1795 lemon juice was made a required part of the diet of sailors. Thus, clinical trials can be used to evaluate new therapies, such as new drug or new indication, new drug combination, new surgical procedure or device, new dosing schedule or mode of administration, or a new prevention therapy.

While designing a clinical trial, it is important to select the population that is best representative of the general population. Therefore, the results obtained from the study can be generalized to the population from which the sample population was selected. It is also as important to select appropriate endpoints while designing a trial. Endpoints need to be well‐defined, reproducible, clinically relevant and achievable. The types of endpoints include continuous, ordinal, rates and time‐to‐event, and it is typically classified as primary, secondary or tertiary. 2 An ideal endpoint is a purely clinical outcome, for example, cure/survival, and thus, the clinical trials will become very long and expensive trials. Therefore, surrogate endpoints are used that are biologically related to the ideal endpoint. Surrogate endpoints need to be reproducible, easily measured, related to the clinical outcome, affected by treatment and occurring earlier than clinical outcome. 2

Clinical trials are further divided into randomized clinical trial, non‐randomized clinical trial, cross‐over clinical trial and factorial clinical trial.

Randomized clinical trial

A randomized clinical trial is also known as parallel group randomized trials or randomized controlled trials. Randomized clinical trials involve randomizing subjects with similar characteristics to two groups (or multiple groups): the group that receives the intervention/experimental therapy and the other group that received the placebo (or standard of care). 13 This is typically performed by using a computer software, manually or by other methods. Hence, we can measure the outcomes and efficacy of the intervention/experimental therapy being studied without bias as subjects have been randomized to their respective groups with similar baseline characteristics. This type of study design is considered gold standard for epidemiological research. However, this study design is generally not applicable to rare and serious disease process as it would unethical to treat that group with a placebo. Please see section “Randomization” for detailed explanation regarding randomization and placebo.

Non‐randomized clinical trial

A non‐randomized clinical trial involves an approach to selecting controls without randomization. With this type of study design a pattern is usually adopted, such as, selection of subjects and controls on certain days of the week. Depending on the approach adopted, the selection of subjects becomes predictable and therefore, there is bias with regards to selection of subjects and controls that would question the validity of the results obtained.

Historically controlled studies can be considered as a subtype of non‐randomized clinical trial. In this study design subtype, the source of controls is usually adopted from the past, such as from medical records and published literature. 1 The advantages of this study design include being cost‐effective, time saving and easily accessible. However, since this design depends on already collected data from different sources, the information obtained may not be accurate, reliable, lack uniformity and/or completeness as well. Though historically controlled studies maybe easier to conduct, the disadvantages will need to be taken into account while designing a study.

Cross‐over clinical trial

In cross‐over clinical trial study design, there are two groups who undergoes the same intervention/experiment at different time periods of the study. That is, each group serves as a control while the other group is undergoing the intervention/experiment. 14 Depending on the intervention/experiment, a ‘washout’ period is recommended. This would help eliminate residuals effects of the intervention/experiment when the experiment group transitions to be the control group. Hence, the outcomes of the intervention/experiment will need to be reversible as this type of study design would not be possible if the subject is undergoing a surgical procedure.

Factorial trial

A factorial trial study design is adopted when the researcher wishes to test two different drugs with independent effects on the same population. Typically, the population is divided into 4 groups, the first with drug A, the second with drug B, the third with drug A and B, and the fourth with neither drug A nor drug B. The outcomes for drug A are compared to those on drug A, drug A and B and to those who were on drug B and neither drug A nor drug B. 15 The advantages of this study design that it saves time and helps to study two different drugs on the same study population at the same time. However, this study design would not be applicable if either of the drugs or interventions overlaps with each other on modes of action or effects, as the results obtained would not attribute to a particular drug or intervention.

Community trial

Community trials are also known as cluster‐randomized trials, involve groups of individuals with and without disease who are assigned to different intervention/experiment groups. Hence, groups of individuals from a certain area, such as a town or city, or a certain group such as school or college, will undergo the same intervention/experiment. 16 Hence, the results will be obtained at a larger scale; however, will not be able to account for inter‐individual and intra‐individual variability.

Field trial

Field trials are also known as preventive or prophylactic trials, and the subjects without the disease are placed in different preventive intervention groups. 16 One of the hypothetical examples for a field trial would be to randomly assign to groups of a healthy population and to provide an intervention to a group such as a vitamin and following through to measure certain outcomes. Hence, the subjects are monitored over a period of time for occurrence of a particular disease process.

Overview of methodologies used within a study design

Randomization.

Randomization is a well‐established methodology adopted in research to prevent bias due to subject selection, which may impact the result of the intervention/experiment being studied. It is one of the fundamental principles of an experimental study designs and ensures scientific validity. It provides a way to avoid predicting which subjects are assigned to a certain group and therefore, prevent bias on the final results due to subject selection. This also ensures comparability between groups as most baseline characteristics are similar prior to randomization and therefore helps to interpret the results regarding the intervention/experiment group without bias.

There are various ways to randomize and it can be as simple as a ‘flip of a coin’ to use computer software and statistical methods. To better describe randomization, there are three types of randomization: simple randomization, block randomization and stratified randomization.

Simple randomization

In simple randomization, the subjects are randomly allocated to experiment/intervention groups based on a constant probability. That is, if there are two groups A and B, the subject has a 0.5 probability of being allocated to either group. This can be performed in multiple ways, and one of which being as simple as a ‘flip of a coin’ to using random tables or numbers. 17 The advantage of using this methodology is that it eliminates selection bias. However, the disadvantage with this methodology is that an imbalance in the number allocated to each group as well as the prognostic factors between groups. Hence, it is more challenging in studies with a small sample size.

Block randomization

In block randomization, the subjects of similar characteristics are classified into blocks. The aim of block randomization is to balance the number of subjects allocated to each experiment/intervention group. For example, let's assume that there are four subjects in each block, and two of the four subjects in each block will be randomly allotted to each group. Therefore, there will be two subjects in one group and two subjects in the other group. 17 The disadvantage with this methodology is that there is still a component of predictability in the selection of subjects and the randomization of prognostic factors is not performed. However, it helps to control the balance between the experiment/intervention groups.

Stratified randomization

In stratified randomization, the subjects are defined based on certain strata, which are covariates. 18 For example, prognostic factors like age can be considered as a covariate, and then the specified population can be randomized within each age group related to an experiment/intervention group. The advantage with this methodology is that it enables comparability between experiment/intervention groups and thus makes result analysis more efficient. But, with this methodology the covariates will need to be measured and determined before the randomization process. The sample size will help determine the number of strata that would need to be chosen for a study.

Blinding is a methodology adopted in a study design to intentionally not provide information related to the allocation of the groups to the subject participants, investigators and/or data analysts. 19 The purpose of blinding is to decrease influence associated with the knowledge of being in a particular group on the study result. There are 3 forms of blinding: single‐blinded, double‐blinded and triple‐blinded. 1 In single‐blinded studies, otherwise called as open‐label studies, the subject participants are not revealed which group that they have been allocated to. However, the investigator and data analyst will be aware of the allocation of the groups. In double‐blinded studies, both the study participants and the investigator will be unaware of the group to which they were allocated to. Double‐blinded studies are typically used in clinical trials to test the safety and efficacy of the drugs. In triple‐blinded studies, the subject participants, investigators and data analysts will not be aware of the group allocation. Thus, triple‐blinded studies are more difficult and expensive to design but the results obtained will exclude confounding effects from knowledge of group allocation.

Blinding is especially important in studies where subjective response are considered as outcomes. This is because certain responses can be modified based on the knowledge of the experiment group that they are in. For example, a group allocated in the non‐intervention group may not feel better as they are not getting the treatment, or an investigator may pay more attention to the group receiving treatment, and thereby potentially affecting the final results. However, certain treatments cannot be blinded such as surgeries or if the treatment group requires an assessment of the effect of intervention such as quitting smoking.

Placebo is defined in the Merriam‐Webster dictionary as ‘an inert or innocuous substance used especially in controlled experiments testing the efficacy of another substance (such as drug)’. 20 A placebo is typically used in a clinical research study to evaluate the safety and efficacy of a drug/intervention. This is especially useful if the outcome measured is subjective. In clinical drug trials, a placebo is typically a drug that resembles the drug to be tested in certain characteristics such as color, size, shape and taste, but without the active substance. This helps to measure effects of just taking the drug, such as pain relief, compared to the drug with the active substance. If the effect is positive, for example, improvement in mood/pain, then it is called placebo effect. If the effect is negative, for example, worsening of mood/pain, then it is called nocebo effect. 21

The ethics of placebo‐controlled studies is complex and remains a debate in the medical research community. According to the Declaration of Helsinki on the use of placebo released in October 2013, “The benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best proven intervention(s), except in the following circumstances:

Where no proven intervention exists, the use of placebo, or no intervention, is acceptable; or

Where for compelling and scientifically sound methodological reasons the use of any intervention less effective than the best proven one, the use of placebo, or no intervention is necessary to determine the efficacy or safety of an intervention and the patients who receive any intervention less effective than the best proven one, placebo, or no intervention will not be subject to additional risks of serious or irreversible harm as a result of not receiving the best proven intervention.

Extreme care must be taken to avoid abuse of this option”. 22

Hence, while designing a research study, both the scientific validity and ethical aspects of the study will need to be thoroughly evaluated.

Bias has been defined as “any systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposure's effect on the risk of disease”. 23 There are multiple types of biases and so, in this review we will focus on the following types: selection bias, information bias and observer bias. Selection bias is when a systematic error is committed while selecting subjects for the study. Selection bias will affect the external validity of the study if the study subjects are not representative of the population being studied and therefore, the results of the study will not be generalizable. Selection bias will affect the internal validity of the study if the selection of study subjects in each group is influenced by certain factors, such as, based on the treatment of the group assigned. One of the ways to decrease selection bias is to select the study population that would representative of the population being studied, or to randomize (discussed in section “Randomization”).

Information bias is when a systematic error is committed while obtaining data from the study subjects. This can be in the form of recall bias when subject is required to remember certain events from the past. Typically, subjects with the disease tend to remember certain events compared to subjects without the disease. Observer bias is a systematic error when the study investigator is influenced by the certain characteristics of the group, that is, an investigator may pay closer attention to the group receiving the treatment versus the group not receiving the treatment. This may influence the results of the study. One of the ways to decrease observer bias is to use blinding (discussed in section “Blinding”).

Thus, while designing a study it is important to take measure to limit bias as much as possible so that the scientific validity of the study results is preserved to its maximum.

Overview of drug development in the United States of America

Now that we have reviewed the various clinical designs, clinical trials form a major part in development of a drug. In the United States, the Food and Drug Administration (FDA) plays an important role in getting a drug approved for clinical use. It includes a robust process that involves four different phases before a drug can be made available to the public. Phase I is conducted to determine a safe dose. The study subjects consist of normal volunteers and/or subjects with disease of interest, and the sample size is typically small and not more than 30 subjects. The primary endpoint consists of toxicity and adverse events. Phase II is conducted to evaluate of safety of dose selected in Phase I, to collect preliminary information on efficacy and to determine factors to plan a randomized controlled trial. The study subjects consist of subjects with disease of interest and the sample size is also small but more that Phase I (40–100 subjects). The primary endpoint is the measure of response. Phase III is conducted as a definitive trial to prove efficacy and establish safety of a drug. Phase III studies are randomized controlled trials and depending on the drug being studied, it can be placebo‐controlled, equivalence, superiority or non‐inferiority trials. The study subjects consist of subjects with disease of interest, and the sample size is typically large but no larger than 300 to 3000. Phase IV is performed after a drug is approved by the FDA and it is also called the post‐marketing clinical trial. This phase is conducted to evaluate new indications, to determine safety and efficacy in long‐term follow‐up and new dosing regimens. This phase helps to detect rare adverse events that would not be picked up during phase III studies and decrease in the delay in the release of the drug in the market. Hence, this phase depends heavily on voluntary reporting of side effects and/or adverse events by physicians, non‐physicians or drug companies. 2

We have discussed various clinical research study designs in this comprehensive review. Though there are various designs available, one must consider various ethical aspects of the study. Hence, each study will require thorough review of the protocol by the institutional review board before approval and implementation.

CONFLICT OF INTEREST

Chidambaram AG, Josephson M. Clinical research study designs: The essentials . Pediatr Invest . 2019; 3 :245‐252. 10.1002/ped4.12166 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]