The instinct to “do your own research” when it comes to your health is a good one. The challenge often is not lack of information, but the opposite.

People are surrounded by studies, headlines, forums, family and friends, often all speaking at once in different directions and with different levels of reliability. How do you move through this abundance of information without getting lost in it?

I am a biostatistician by training. In my work, I study how medical evidence is generated and interpreted. I have been on the other side of that process, trying to make sense of medical information that could affect my health or the health of my loved ones.

Over time, I’ve found myself returning to the same road map when doing my own research to answer personal health questions. By sharing how I approach this process as a scientist, I’m hoping this method can help others sift through medical information carefully.

Before trying to answer a medical question, you first need to frame it in a way that can be answered with evidence.

In practice, this means identifying four things. First is the exposure or intervention, such as the medication, treatment, lifestyle change or other intervention you care about. Second is the outcome, such as whether you get sick or your symptoms improve. Third is the population, that is, whether you’re answering this question for yourself or someone else. And fourth is the time frame.

Suppose I’m interested in helping my pregnant sister understand whether taking fish oil, which contain omega-3 fatty acids – specifically DHA – during pregnancy will help lower her chances of having a preterm birth.

We can put these variables in what I call an evidence table.

Laying out the variables this way helps you be precise about exactly what question you’re asking. It will also help make sure the studies you draw on actually match these variables.

Now, I turn to the medical literature.

In medical research, different groups of researchers often study similar problems in different ways, across different populations and settings. This means that no single study usually gives the full picture for every person interested in a particular health question.

The first thing I usually look for are systematic reviews. These are studies that bring available work related to a particular scientific question together to try to understand all of the existing evidence.

I typically search for systematic reviews in a medical database such as PubMed. PubMed is a free, publicly available database of biomedical literature maintained by the National Library of Medicine. One important caveat, however, is that just because a study appears in PubMed does not mean it is necessarily of high quality or trustworthy. PubMed indexes articles from thousands of journals, so the presence of a study there is not necessarily a stamp of approval. However, PubMed is still a good place to find good research as long as you know how to filter out the weaker studies.

In the case of the question on how taking fish oil – specifically DHA – affects pregnancy, I might start by searching for something like “DHA preterm birth systematic review” in PubMed. When I did this in July 2026, I got 23 results.

The top result was a systematic review published in 2020 titled “Risk factors for postpartum depression: An evidence-based systematic review of systematic reviews and meta-analyses.” This might be a good place to start if I were interested in assessing the effects of DHA on postpartum depression, but the outcome I am interested in is preterm........

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