Evidence-Based Medicine Starts with Asking the Right Questions

The cornerstone of evidence-based medicine is critical thinking. A practitioner must constantly refer to the latest clinical research and medical literature to stay current with advances in the field, and then use that information to create a treatment strategy for a particular patient. Every step in the treatment process, from the diagnostic tests run to the course of treatment ultimately prescribed, has to be scrutinized for usefulness. That scrutiny starts with identifying the right questions to ask.

This question must be focused enough to yield actionable insight. There are any number of queries that come up in a clinical scenario, and finding one that is structured properly to provide the right sort of information is vital.

A well-formed question should address four major elements, described by the abbreviation PICO:

  • P – the Population or Patient at hand. What unique demographic information is required to solve this issue?
  • I – the Intervention or exposure. What steps need to be undertaken to treat or cure this condition? What tests will need to be run, and what course of treatment will ultimately be prescribed?
  • C – the Comparison. How does this particular course of treatment compare with the alternative?
  • O – the Outcome. What will happen if the treatment is pursued for this particular patient?

In some case, an additional variable, T (for time) is added to this framework.

Take, for example, this case Medical Research Essentials by Rania Esteitie, MD: A 50-year old healthy male patient comes into a clinic, and wants to know whether it is a good idea to regularly take aspirin to prevent heart disease. In this case, you know the “patient” is middle-aged and male, with no risk factors. You know the “intervention” is aspirin, and that the “comparison” is not taking aspirin. The “outcome” being discussed is cardiovascular disease.

An example of a focused, well-defined question is: “in an otherwise healthy male with no existing medical conditions, what is the benefit of taking aspirin versus no aspirin at preventing cardiovascular disease?”

Once the question has been developed, it is time to find evidence to answer or refine it. The best way to do this is to combine searching available literature, such as journals and databases, with personal experience as a clinician. Choosing appropriate search terms is an important part of this process, as the results yielded will be directly based on the terms that have been input. One efficient method involves the use of Boolean operators, such as AND and OR, which allow for the combination or exclusion of particular factors. Searches can be further refined by time period (e.g. not performed longer than 10 years ago) or survey type (e.g. randomized controlled trials only).

For more information about evidence-based medicine and asking the right questions, please download our free eBook Why Evidence-Based Medicine?.

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