Minimal clinically important differences (MCID) are patient derived scores that reflect changes in a clinical intervention that are meaningful for the patient. At present, there are a number of different methods to obtain an MCID, as there a number of different factors that can influence the MCID value. This clinimetric corner outlines the hidden challenges associated with identifying a viable MCID and possible suggestions to improve the future development of these single scores.
Keywords: Global rating of change; Minimal clinically important difference; Outcomes measures.