Observational studies: cohort and case-control studies

Plast Reconstr Surg. 2010 Dec;126(6):2234-2242. doi: 10.1097/PRS.0b013e3181f44abc.


Observational studies constitute an important category of study designs. To address some investigative questions in plastic surgery, randomized controlled trials are not always indicated or ethical to conduct. Instead, observational studies may be the next best method of addressing these types of questions. Well-designed observational studies have been shown to provide results similar to those of randomized controlled trials, challenging the belief that observational studies are second rate. Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. In this review article, the authors describe these study designs and methodologic issues, and provide examples from the plastic surgery literature.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Bias
  • Case-Control Studies*
  • Cohort Studies*
  • Evidence-Based Medicine*
  • Humans
  • Plastic Surgery Procedures / methods*
  • Plastic Surgery Procedures / standards*
  • Prospective Studies
  • Randomized Controlled Trials as Topic
  • Retrospective Studies