Global rating of change: perspectives of patients with lumbar impairments and of their physical therapists

Background: Global rating of change (GROC) scores provide a means of measuring patients' self-perceived change in health status over time. Objectives: The purposes of the study were to examine agreement of GROC ratings between the patient (GROCp) and the treating therapist (GROCt), the impact on the minimal clinically important difference (MCID) estimates by reporting resources, and the relationships between the subjective GROC scores and objective outcome measures. Methods: Data from 52,767 patients with orthopedic lumbar spine impairments treated in 623 outpatient rehabilitation clinics in 34 states (United States) were analyzed. Patient's functional status (FS) before and after the treatment was measured using the Lumbar Computerized Adaptive Testing (LCAT) survey (0-100 scale). The GROC ratings were obtained from both the patients and their caring therapists at discharge. Results: On average, GROCp (mean [(SD]=3.1 [4.1]) was 1.9 points lower than GROCt (mean [SD]=5.0 [1.9]). There were negligible differences between MCID estimates derived from the patients' GROC ratings (MCID cutoff=9.2) and from the therapists' GROC ratings (MCID cutoff=9.5). While only analyzing patient data whose GROCp >= 0, the intraclass correlation coefficient between GROCp and GROCt was 0.61, the GROCp correlated with FS at intake at r=0.12, with FS at discharge at r=0.56, and with FS change scores at r=0.47. Conclusions: Therapists tended to report higher GROC ratings than their patients did but there were negligible differences between MCID estimates derived from GROCp and that derived from GROCt.