Test–retest reliability and responsiveness of the Self-Regulation Assessment in a rehabilitation population: A prospective multicentre validation study

ObjectiveThis study aimed to examine the test-retest reliability and responsiveness of the Self-Regulation Assessment, a recently developed patient-reported outcome measure designed to evaluate self-regulation in a multi-diagnostic rehabilitation population.DesignA prospective cohort study following COSMIN guidelines. Participants completed the Self-Regulation Assessment and other measurements at start of rehabilitation (T0), 6 months later (T1), and 2 weeks after T1 (T2). Test-retest reliability (T1-T2) was quantified by intraclass correlation coefficient values, Bland-Altman plots, and the smallest detectable change. Responsiveness (T0-T1) was quantified by hypothesis testing, effect size, area under the curve, and minimal important change based on the anchor Global Rating of Change scale of self-regulation.Setting and participantsInpatients and outpatients of 14 Dutch rehabilitation institutions with various diagnosis.Main measureThe Self-Regulation Assessment.ResultsIn total, 555 patients completed the Self-Regulation Assessment at T0 and T1 and 167 patients at T1 and T2. In inpatients and outpatients, the Self-Regulation Assessment showed adequate to good reliability, with smallest detectable changes ranging from 16.0 to 22.9 points at individual level and 1.5 to 3.3 at group level for outpatients and inpatients, respectively. Significant changes (T0-T1) were observed in both groups, with a small effect size for inpatients and large for outpatients. Hypothesis testing indicated near sufficient responsiveness in both groups (67% confirmed). Minimal important change values ranged from 6.25 to 9.8 points for outpatients.ConclusionThe Self-Regulation Assessment demonstrated sufficient reliability and detected changes at group level, but was not suitable for detecting changes at individual level in outpatient rehabilitation.