Responsiveness of the P4, Patient Specific Functional Scale 2.0, Satisfaction and Recovery Index, and SF-12 in Patients With Musculoskeletal Disorders.

Background Recently, estimation of intervention effects has been recommended using minimum important change (MIC). This study aimed to investigate the responsiveness of the four-item pain intensity measure (P4), Patient Specific Functional Scale 2.0 (PSFS 2.0), Satisfaction and Recovery Index (SRI), and physical (PCS) and mental component summary (MCS) scores of the SF-12v2® Health Survey Acute (QualityMetric Inc. & Fukuhara S, Kyoto) in patients with musculoskeletal disorders and to estimate their MICs. Methodology Data of outpatients receiving musculoskeletal physical therapy were collected using a survey in multi-center cohorts. The participants completed the first survey before their first physical therapy session and the second survey after the third to seventh sessions. Responsiveness was assessed by investigating the area under the receiver operating characteristic curve (AUC) and by investigating prior hypotheses with correlations between change scores. In the former method, the AUCs of the measures were calculated for discriminating improved cases (i.e., 11-point Global Rating of Change Scale (GRCS) ≥ 2) and non-improved cases (i.e., GRCS < 2). The MIC scores were estimated with GRCS using the predictive modeling method. Results Data from 100 participants were analyzed. The PSFS 2.0 satisfied both acceptable responsiveness criteria, the P4 and SRI satisfied the moderate responsiveness criterion of the construct approach only, and the PCS and MCS satisfied both poor responsiveness criteria. The MICs were 1.64, 2.92, 6.16, 4.49, and 1.67 for the P4, PSFS 2.0, SRI, and PCS and MCS scores, respectively. Conclusion The PSFS 2.0 has acceptable responsiveness and can be used to determine treatment effects in clinical practice, while the P4 and SRI can also be used in some cases.