How to Read and Apply Clinical Studies in Daily Practice

As doctors of optometry, we must engage with clinical research to improve patient care. We want our care to be evidence-based, current, and aligned with best practices.

Our field is evolving rapidly and keeping up with research allows us to make informed decisions about emerging technologies and therapies. This benefits our patients, and also allows us to maintain credibility in a competitive landscape.

There is no doubt that it can be a challenge to keep up with research while maintaining a busy clinical practice. Reading research involves not only considering the results but also the trustworthiness of the study. As we approach research literature, we must determine whether the research is sound and how it may be clinically applicable.

When evaluating the rigor of a trial, study design is one of the first things to examine.

Randomized, double-masked, placebo-controlled trials are generally considered the most rigorous design for assessing a treatment effect (1). Unlike most other study types, randomized clinical trials (RCTs) can show causation (proving that the intervention caused the outcome).

It is not always possible to carry out trials with this structure, especially for rare conditions in evolving fields. In some cases, other study designs may be more practical for answering real-world questions. There are also other considerations, such as time commitment and cost, that can sometimes lead researchers to choose other designs.

Studies that are not randomized, double-masked, and placebo-controlled can also support clinical decision-making, though typically, these studies can only show correlations, not causation. A retrospective study can provide great insight. A meta-analysis analyzes multiple clinical studies to cover a population of sometimes thousands of patients. Population health studies, longitudinal studies, and even informal surveys can also provide valuable data on large patient populations. Case reports of uncommon conditions can make a meaningful contribution to clinical understanding. The important thing is to be aware of study design and to keep the level of rigor in mind when deciding whether to make changes to patient care.

Look for reputable journals in which articles undergo rigorous peer review.

There are key journals on specific topics that serve as authoritative sources for the latest developments in the field. These journals are included in PubMed, and it is possible to look up their impact factor, which represents the frequency that the average article in the journal is cited, as well as, for some impact rankings, the prestige of the citing journal. There are also indirect ways of learning about research. There are well-accepted trade publications in optometry that provide important insights from a clinical or academic perspective, but do not include peer review. These publications can provide an overview of research as well as expert commentary, clinical summaries, and practical guidance. If particular research is central to your practice, or you would like more detailed information, you can then go to the original peer-reviewed journal papers.

Thought leaders can act as a channel for information on research. Hearing them speak at conferences can be a valuable source of information, but there are a few things to keep in mind. These speakers may have a different approach in their clinic. Their focus may be specialized, and their perspective on research may not reflect the needs of primary care optometrists.

There is also potential for bias. Even if there is a lack of bias (which is the case more often than not), a speaker might present prospective, randomized mass trials in the same vein as a case report publication, even though they do not involve the same rigor. Unless the speaker shares this information, there is no way for the doctor in attendance to know without reviewing the actual paper.

Reviewing the researchers can help you evaluate perspective and expertise within a study. Are the researchers leaders in their field with a track record of rigorous scientific investigation and unbiased, independent inquiry? You can evaluate their affiliations, assess their past work, and, if you have attended presentations by these researchers, you may have an impression of whether they seemed trustworthy and whether the research information you brought back to your practice was clinically relevant.

It is important to note whether the authors have a conflict of interest. Many times, the person who invented a product or did the original research has the greatest store of relevant knowledge and is a logical initial investigator, because no one else will know much about the specifics of the drug or the device. Conflict of interest does not mean you should not read a paper, but it should be taken into consideration.

It is also good to check whether the funding source includes the organization that produces or sells the product being studied. If the answer is yes, it does not necessarily mean that the study is not valuable; some of the best studies have been funded this way.

The title of a study report and its keywords are often your first exposure to a trial. The next step is generally to read the abstract. Spending five minutes with these elements should give you a first impression about the trustworthiness of the study and whether it might be relevant to your practice.

The methods section describes study design elements, such as randomization, masking, or controls. This section will also give the number of participants in the trial. This is a vital consideration. Is it a study of 12 patients or 200? A trial with 12 participants can provide ideas for consideration, but it is generally not substantive enough to change the way a doctor practices.

It is also good to look at the diversity of participants. Is there racial and gender diversity? Is there age diversity? Is the population studied similar to that treated in your clinic?

The result section shows you what actually happened in the study. Here, you focus on what outcomes were measured and whether the results showed a meaningful difference.

You want to look for a statistically significant effect, which provides evidence that the observed result is unlikely to have occurred by chance. A quick tutorial: a p-value of less than 0.05 is the threshold required to achieve statistical significance (meaning we can be more than 95% confident that the result is not due to random chance). So, a p-value of 0.01 or 0.001 is highly significant, while a p-value of 0.1 or 0.06 is statistically insignificant, essentially a ‘null’ result. It is also important to consider the sample size, because very large studies can produce statistically significant p-values even for small effects. In contrast, small studies may miss meaningful effects due to insufficient sample size. A small study with highly statistically significant results generally indicates a powerful treatment effect.

This section, along with the discussion section, is also a place to assess whether the study accounted for confounding factors. Look for explanations of how potential confounders, which could create false associations between the treatment and outcome, were identified and addressed.

The discussion section helps you understand the results of a trial or study. It can put results in context, interpret statistical findings, and suggest implications for practice.

Best practices are for authors to address study limitations in this section and suggest future research - whether or not authors have done this is another way to assess their credibility. For example, if a study was conducted with a small number of participants, the authors should note that their study shows promising data but needs to be confirmed with a larger scale study.

Reading research alongside running a busy clinical practice can be a challenge. One approach is to dedicate a certain amount of time to this reading one day per week, even if you can only spare ten to fifteen minutes.

Another approach is to focus on the more rigorous and authoritative studies related to a topic that interests you. It would also be an option to attend lectures by doctors who read these high-level studies and put them in their presentations. If a certain study or trial seems particularly relevant to your practice, you can then read the original paper.

Some doctors also look up current research with a patient in the chair. They have found that patients respond favorably to a comment such as, “You know, I’m really curious about the latest thinking on this subject,” followed by a quick search.  

When deciding whether to integrate research findings into your practice, assess whether the results fit what you see clinically. Consider incorporating the new information into your practice through experimentation with a few patients at the beginning. If the results are encouraging, the new findings may become part of how you diagnose or treat patients.

Additionally, share the research findings with your patients. Communicating research helps patients understand the validity of your approach. It helps them understand that you are staying up to date on the latest innovations and knowledge.

Patients are more aware of research findings than they were in the past. They are coming in armed with information gleaned from online sources, and this information is not always accurate. Patients often appreciate having access to studies related to their area of interest. We must keep pace with evolving research and be able to help patients know whether what they are seeing is fact or fiction.