Abstract
Increasing emphasis is placed on physical functional measures to examine treatments for chronic low back pain (CLBP). The Quebec Back Pain Disability Scale (Hindi version) (QBPDS-H) has never been evaluated for responsiveness. The objectives of this study were to (1) examine the internal and external responsiveness of the Quebec Back Pain Disability Scale (Hindi version) (QBPDS-H) and (2) find out the minimal clinically important difference (MCID) and minimal detectable change (MDC) in the functional ability of patients with chronic low back pain (CLBP) undergoing multimodal physical therapy treatment. In this prospective cohort study, QBPDS-H responses were recorded at the baseline and after eight weeks from 156 CLBP patients undergoing multimodal physiotherapy treatment. To differentiate between the clinically unimproved (n = 65, age: 44.16 ± 11.8 years) and clinically improved (n = 91, age: 43.28 ± 10.7 years) scores of patients from the initial assessment to the last follow-up, the Hindi version of the Patient's Global Impression of Change (H-PGIC) scale was utilized. Internal responsiveness was large (E.S. (pooled S.D.) (n = 91): 0.98 (95% CI = 1.14-0.85) and Standardized Response Mean (S.R.M.) (n = 91): 2.57 (95% CI = 3.05-2.17)). In addition, the correlation coefficient and receiver operative characteristics (R.O.C.) curve were used to assess the QBPDS-H external responsiveness. MCID and MDC were detected by the R.O.C. curve and standard error of measurements (S.E.M.), respectively. The H-PGIC scale showed moderate responsiveness (ρ = 0.514 and area under the curve (A.U.C.) = 0.658; 95% CI, 0.596-0.874), while the MDC achieved 13.68 points, and the MCID was found have 6 points (A.U.C. = 0.82; 95% CI: 0.74-0.88, sensitivity = 90%, specificity = 61%). This study shows that QBPDS-H has moderate levels of responsiveness in CLBP patients receiving multimodal physical therapy treatment, so it can be used to measure the changes in disability scores. MCID and MDC changes were also reported with QBPDS-H.