Method Is Everything: Evaluating Results by Study Design

OBJECTIVE: To review advantages and disadvantages of commonly used study design strategies and examine issues in interpretation of study results including bias and confounding. DATA SOURCES: Clinical literature, established epidemiologic texts. STUDY SELECTION: Not applicable. DATA EXTRACTION: Not applicable. DATA SYNTHESIS: The increasing flow of research reports on various therapeutic agents and procedures places managed care pharmacists in the position of evaluating the clinical relevance of new information and its applicability to clinical decision-making in their organizations. A solid understanding of study design strategies such as cohort, case-control, and clinical trials, and the flaws inherent in each, is invaluable for accurate interpretation of any study results. Some design strategies are more appropriate than others to answer certain clinical questions. The randomized, controlled, blinded clinical trial is the most reliable design for assessing therapeutic effects of pharmacologic agents. CO...