Evaluation of the outcome of evidence-based practice decisions in individual patients or patient groups is step five in the evidence-based practice approach. Outcome measures are any measures that reflect patient status. Status or outcome measures can be used to detect change over time (eg, treatment effects), to discriminate among clinical groups, or to predict future outcomes (eg, return to work). A variety of reliable and valid physical impairment and disability measures are available to assess treatment outcomes in hand surgery and therapy. Evidence from research studies that includes normative data, standard error of measurement, or comparative scores for important clinical subgroups can be used to set treatment goals, monitor recovery, and compare individual patient outcomes to those reported in the literature. Clinicians tend to rely on impairment measures, such as radiographic measures, grip strength, and range of motion, although self-report measures are known to be equally reliable and more related to global effects, such as return-to-work. The process of selecting and implementing outcome measures is crucial. This process works best when team members are involved and willing to trial new measures. In this way, the team can develop customized outcome assessment procedures that meet their needs for assessing individual patients and providing data for program evaluation.