How to Review a Clinical Study

Making sense of the science

The COVID-19 pandemic has led to new forms of personal protective equipment, new ways of testing and diagnosing illness, and new treatments and vaccines. And they’ve all come to fruition thanks to clinical studies. Clinical studies are the foundation on which modern medicine is built. Little by little, step by step, researchers and clinicians make medical advances to benefit the common good. But these studies are only as good as the people who effectively read and interpret them.

How can you ensure that you’re correctly digesting a clinical study? HealthTrust’s Angie Mitchell, RN, former AVP of Clinical Services, and Holly Moore, MSN, CCRN-K, Director, Clinical Services, walk through the basics of a clinical study, including key components, common jargon and pitfalls to avoid.

Clinical study basics

A clinical study is a medical observation or experiment done on people to learn more about the effects of a behavior, product or procedure.

What are the types of clinical studies?

Observational study: Researchers observe people in their normal settings and collect information. They may segment people into groups or “cohorts,” to look at the differences. For example, researchers discovered several comorbidities increased the risk of severe illness and hospitalization in COVID-19 patients. The researchers do not assign interventions. Rather, they simply observe in order to discern the strength of the relationship between the risk factor and the disease.
Investigational study: Also known as clinical trials, these studies test an assigned intervention on people. It could be a new medicine, procedure or behavior. The primary reason for an investigational study is to determine whether a new treatment is safe and effective. Often, the study includes a control group, which does not receive the intervention, and the researchers will measure the predetermined outcomes to see if there are any improvements.

Who conducts clinical studies?

Principal investigator: The study leader, who is often a medical doctor or advanced clinical practitioner
Research team: Medical doctors, nurses, scientists, dietitians, social workers and other healthcare professionals

Who pays for clinical studies?

Government agencies
Drug makers
Technology companies
Other product suppliers and manufacturers
Nonprofit organizations

“A clinical study may be funded by a number of entities, with the most common sources being governmental and private industry,” says Moore.

Suppliers often support research, which is a positive, because it helps advance medicine and provide better treatments and patient care. But it’s important to watch out for potential bias or conflicts of interest, which can happen if a supplier is compensating the researchers. “In these situations, you’ll want to look at the study through a more discretionary lens,” advises Mitchell.

Key terms

Randomized: Each participant is indiscriminately put into either the test group or control group, so that every individual has an equal chance at receiving the intervention.
Controlled: The study has two groups for the purpose of comparing their results. For example, one group is given a treatment and the other is not.
Variable: This is the person, thing or behavior that the researchers are trying to measure.
Placebo: A substance that has no therapeutic effect.
Investigational: A drug, device or procedure is undergoing active study; it hasn’t yet been formally approved for use.
Cohort: Another word for group.
Intervention: Participants are exposed to a treatment to establish whether it is effective.
Single-blind: The participants don’t know if they are receiving the intervention (test group) or not (control group).
Double-blind: Neither the participants nor the researchers know who is in which group.
IRB: The Institutional Review Board is responsible for protecting participants by ensuring the study is adhering to standards and guidelines.
Sample size: The number of study participants.
Phase: With clinical trials, there are often three or four phases. The later phases of the study tend to get larger as the researchers establish safety and efficacy.
Retrospective: A study that looks in the past to examine two similar groups where one group has a disease or condition, or exposure to a particular substance, and the other does not have the disease, condition or exposure. It’s also known as a case-control study.
Prospective: A study that looks at the present and future, where individuals in a study are followed over time, and data about them is collected as their lives and conditions evolve.
Meta-analysis: This refers to reviewing data from several independent studies on a similar subject to look at trends.

Key components of a clinical study

When starting your research review, you first might quickly read abstracts when deciding which studies are relevant to the topic at hand. “Don’t stop there,” says Mitchell. “Read the entire article because there are always nuances.” If you’re new to reading clinical studies, here are some sections you might review:

Abstract: The high-level summary of the study
Methods: The outline of the design of the experiment, participants, intervention provided, timeline, primary outcome of interest, data collected and type of statistical analysis
Results: The detailed contrast and comparison between the control and study groups
Conclusions and limitations: A discussion surrounding implications of findings, possible future research needs and study weaknesses that may affect its applicability

Bias alert!

Ask these questions of the study to help you determine how much opportunity exists for potentially biased results:

Was the study blinded?
Was the sample size small, making it less applicable to the larger population?
Who funded the study?
Do the researchers have any disclosures or conflicts of interest?
Was the study peer-reviewed and published in a reputable scientific journal?

Final thoughts

Be patient: If you aren’t familiar with the topic, it might take you longer to process the information.
Practice makes perfect: The more studies you read, the more you’ll start to notice that there is a rhythm to them and the more proficient you will become at interpreting what they’re saying and not saying.
Ask around: Look to your physicians and advanced practice nurses to help you understand the studies and/or the purported results.

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