Observational studies: a review of study designs, challenges and strategies to reduce confounding.

摘要: There are several methods in which one can assess the relationship between an intervention and outcome. Randomized controlled trials (RCTs) considered as gold standard for evaluating interventions. However, many questions of clinical importance, RCTs would be impractical or unethical. Clinicians must rely on observational studies best available evidence when unavailable. This article provides overview research designs to facilitate understanding appraising their validity applicability practice. Major methodological issues including selection bias confounding also discussed. In addition, strategies minimize these problems design analytical phases a study highlighted. Knowledge strengths, weaknesses recent advances assist clinicians make informed decisions about whether particular provide useful information enhance patient care.