Editorial Commentary: Shoulder Minimal Clinically Important Difference and Patient Acceptable Symptomatic State Metrics Provide a Foundation for Interpreting Patient-Reported Outcomes.

Limited data have been previously published on the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) after the treatment of shoulder instability. The MCID and PASS are useful in understanding how well one treatment performs against another and whether the differences in outcomes between treatments are clinically important to patients, supporting either treatment, performing power calculations for clinical studies and trials, and making an assessment as to whether a patient's final clinical state after treatment is reasonable. Anchor-based and distribution methods of MCID calculation have been performed for a variety of patient-reported outcome measures after the treatment of shoulder instability. In general, there is a high degree of variability in the MCID and PASS metrics reported in a relatively limited number of studies. Because of the importance of these metrics in interpreting clinical data, an emphasis should be placed on improved research to further define these metrics, along with others including substantial clinical benefit and maximal outcome improvement, for a variety of different shoulder instability pathologies as well as treatments. Nevertheless, the initial set of MCID and PASS metrics published provides a solid foundation for interpreting patient-reported outcome measures in the treatment of shoulder instability.