Editorial Commentary: The Alphabet Soup of Understanding Clinical Shoulder Research: MCID (Minimal Clinically Important Difference), PASS (Patient Acceptable Symptomatic State), SCB (Substantial Clinical Benefit), and Now . . . MOI (Maximal Outcome Improvement).

Abstract

A variety of metrics have been developed for the purposes of understanding how to use and interpret patient self-reported functional outcome scores after treatment. Among these, the maximal outcome improvement (MOI) can now be added to the list. Limitations of other metrics including the minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit are ceiling effects if starting function is relatively high. The MOI now provides a measure of improvement based on the patient's total range of possible improvement to determine whether a satisfactory state was achieved. The value of the other measures, such as the minimal clinically important difference, is in interpreting studies comparing treatments to determine clinical significance as opposed to statistical significance, as well as performing sample size calculation for prospective studies, but may be limited in interpreting the outcomes of individual patients. The MOI provides a metric-in this case for patients after arthroscopic rotator cuff repair-that can be easily used in the clinic for assessment of improvement in an individual patient's function without limitations resulting from how good or bad his or her initial function is.