How to interpret a Study
Often, physicians, and scientists conduct clinical trials to better evaluate a product, procedure, and/or treatment effectiveness. These studies and their outcomes are typically published as scientific papers in academic journals to inform their peers within the scientific community. But these articles can also serve as a valuable resource to patients, presenting information about available treatment options and their effectiveness. Although having access to this information is great, it is not always helpful without fully understanding how to interpret a scientific paper or the assess the soundness of a clinical study.
Because many scientific papers are written by physicians or scientists and contain complex, clinical terms and medical jargon, patients sometimes have difficulty interpreting what they mean, what significance they have, and how the outcomes compare to other studies. While many studies are, in fact, informational and helpful, others can be difficult to interpret and can present data in a way that is misleading. By asking yourself the below 6 questions while reading a scientific paper, you can better assess the study’s credibility and value.
1. Who published the study?
What are the credentials of the author? Is the person publishing the study a scientist? A doctor? An employee? If it’s someone who works for a specific company, they may have an invested interest in outcomes and may leave out specific data points, ‘cherry picking’ more favorable results. It is important that the author of the study is unbiased and has a reputable educational background, as that makes a study more reliable.
2. When was the study published?
The older a study, the greater the chance the information has become outdated. For the most up-to-date information, it is best to find the most recent data available.
3. What type of study is it?
The type of article indicates its overall quality and reliability. Below is a list of types of scientific papers.
a) Peer-reviewed articles
Also known as scholarly publications, peer-reviewed articles are usually the most reliable. The peer-reviewed process takes an author’s scholarly work to the scrutiny of others who are experts (peers) in the field. A study that is peer-reviewed has been published in a reputable journal.
b) Randomized controlled trials
These studies randomly assign participants to an experimental group (which receives the intervention that is being tested) or a control group (which receives an alternative treatment or placebo). These are very reliable studies because the randomization is one of the best ways to reduce bias.
c) Prospective Cohort Studies
Prospective cohort studies are longitudinal studies that follow a group of participants (cohort) into the future for a period of time (often many years) while observing their environment, their exposure, their treatment (if applicable) and their outcomes. A major advantage of prospective cohort studies is the ability to study multiple outcomes in one cohort. The disadvantage is that these studies can be very expensive, and they take a long time to complete.
d) Retrospective Studies
Retrospective studies take a group of participants who share an outcome (such as one particular disease, one profession etc.) and looks at their experiences, which may include practices, exposures, race, age, gender and so on. Such studies often include questionnaires. The advantage of retrospective studies is that they are quick and easy to perform. The disadvantage is that their results are less reliable.
e) Expert Opinion
Although the expert opinion of an experienced professional in an area of study can provide valuable insight, it does not usually include any experimentation, as it relies solely on the personal experience and testimony of the expert or group of experts. As a result, expert opinion can be more biased than a scientific study.
Blogs are the lowest in quality and reliability because they provide anecdotal experiences from non-experts, as they can be written by anyone, even those with no medical or scientific background. The personal experience of one individual does not mean that everyone will have the same experience. Anecdotal experiences are like restaurant reviews. One bad review should not deter you from going to that restaurant. You would need to read many reviews to have an understanding of the overall experience at that restaurant and this applies to blogs as well.
4. When comparing studies, are you comparing apples to apples?
Make sure the studies you are comparing are asking the same questions and are structured in a similar manner with similar populations, sample sizes, and inclusion and exclusion criteria. Otherwise, their results may not be comparable. A good way to ensure you are comparing similar studies is to read the methods section. In this section you will find information on how the studies were was conducted, the sample size, (number of participants), the type of participants (men, women, children, race) and so on.
5. What is the p-value and how was the data collected?
In a clinical study, the p-value represents the probably or likelihood of achieving similar results in a greater population size. The p-value is usually found in the results section. A value of <0.1 means the results are statistically significant and the author(s) anticipate(s) that if you expand the sample size, similar results would be achieved. Also in the results section, you would find how the data was collected. Qualitative data uses descriptive words to represent results (ex. Hair colour, symptoms, patient experience etc). Quantitative data uses numbers to measure results (ex. height, weight, PSA value etc.). While both types of studies are valuable, quantitative research is preferred among the scientific community as it is more objective and easier to measure and reproduce.
6. What are the limitations of the study?
All peer-reviewed journals publish the limitations of their study. Limitations are important to share because they place the research findings in context. Properly acknowledging the limitations of a study makes the study more credible as it recognizes the problems and constraints of the study as opposed to hiding them, or waiting for other reviewers to find them.
While it is natural to feel overwhelmed with the extent of information available, these 6 probing questions can help you better understand the information you are reading so as to better inform the decisions you make to optimize your health. Before you make any final decisions, check with your doctor. Since everyone is different, your doctor, who knows you the best, is in the best position to help you apply the information in the proper context for your personal health benefit.