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Question Types

Question Types

Study types to answer clinical questions                                 

Image adapted from: Szajewska H. (2018). Evidence-Based Medicine and Clinical Research: Both Are Needed, Neither Is Perfect. Annals of Nutrition & Metabolism, 72 Suppl 3, 13–23.


Primary Question Types:

  • Therapy: how to select treatments to offer our patients that do more good than harm and that are worth the efforts and costs of using them.
  • Diagnostic tests: how to select and interpret diagnostic tests, in order to confirm or exclude a diagnosis, based on considering their precision, accuracy, acceptability, expense, safety, etc.
  • Prognosis: how to estimate a patient's likely clinical course over time due to factors other than interventions
  • Harm / Etiology: how to identify causes for disease (including its iatrogenic forms - illness caused by medical examination or treatment)

Other Question Types:

  • Clinical findings: how to properly gather and interpret findings from the history and physical examination.
  • Clinical manifestations of disease: knowing how often and when a disease causes its clinical manifestations and how to use this knowledge in classifying our patients' illnesses.
  • Differential diagnosis: when considering the possible causes of our patient’s clinical problem, how to select those that are likely, serious and responsive to treatment.
  • Prevention: how to reduce the chance of disease by identifying and modifying risk factors and how to diagnose disease early by screening.
  • Qualitative: how to empathize with our patients’ situations, appreciate the meaning they find in the experience and understand how this meaning influences their healing.

From: Duke University Medical Center Library & Archives - Evidence-Based Practice: PICO

This video explains common question types and what kinds of studies will best address those questions:

Video created by Molly Montgomery, Idaho State University Libraries.