Measuring clinically meaningful change following mental health treatment.

Assessment of clinically meaningful change is useful for treatment planning, monitoring progress, and evaluating treatment response. Outcome studies often assess statistically significant change, which may not be clinically meaningful. Study objectives are to: (1) evaluate responsiveness of the BASIS-24 using three methods for determining clinically meaningful change: reliable change index (RCI), effect size (ES), and standard error of measurement (SEM); and (2) determine which method provides an estimate of clinically meaningful change most concordant with other change measures. BASIS-24 assessments were obtained at two time points for 1,397 inpatients and 850 outpatients. The proportion showing clinically meaningful change using each method was compared to the proportion showing change in global mental health, retrospectively reported change, and clinician-assessed change. BASIS-24 demonstrated responsiveness at both aggregate and individual levels. Regarding clinically meaningful improvement and decline, SEM was most concordant with all three outcome measures; regarding no change, RCI was most concordant with all three measures.