Here’s a question:

That is a perfectly good question if you’re a doctor or policy maker concerned with effective treatment methods, but it won’t work for a systematic review or, for that matter, for a research study.

First, you have to be clearer about the populations and conditions you want to examine. What kind of patients are you talking about here? What do you mean by kidney disease?

This is the first step in PICO (D): write a clear and precise definition of your Population. When we talk about Population, we’re talking about the specific types of people you’re interested in, as well as the condition those people are experiencing.

This step is important: unclear or imprecise definitions can create confusion when you’re searching for studies and sharing your results.

Let’s look at the initial question again:

So what do you mean by patients? Not everyone with kidney disease is a patient, so do you want to require that research participants be under medical care? Are you including children and adults? Replace patients with adults to be more specific.

Next, you have to clarify what you mean by kidney disease.

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