The choice of outcome measure in orthopedic clinical research studies is paramount. The primary outcome measure for a study has several implications for the design and conduct of the study. These include: 1) sample size determination, 2) internal validity, 3) compliance and 4) cost. A thorough knowledge of outcome measures in orthopedic research is paramount to the conduct of a quality study. The decision to choose a continuous versus dichotomous outcome has important implications for sample size. However, regardless of the type of outcome, investigators should always use the most 'patient-important' outcome and limit bias in its determination.
Keywords: Evidence-based medicine; outcomes; research.