Validity of the Global Rating of Change in patients with chronic low back pain

Abstract

Background The Global Rating of Change (GROC) is a widely used outcome measure that aims to capture change in overall health status. There is limited evidence on the validity of the GROC for measuring change among patients with chronic low back pain (CLBP), and little is known about which clinical variables explain the GROC score. Objectives This study aimed to assess the validity of the GROC in measuring change, and identify which clinical variables correlate with the GROC score in patients with CLBP. Design Retrospective observational study. Methods This secondary analysis included clinical data from patients with CLBP enrolled in a physiotherapy program. Data on pain intensity, function, pain catastrophizing, depression, and quality of life were collected at baseline and discharge, and the GROC scale was completed at discharge. We performed Spearman correlation and linear regression analyses to examine the relationship between the GROC and change/discharge scores for all clinical variables. Results Data from 102 participants were analysed. Spearman correlations between the GROC and discharge scores were greater (−0.46 to −0.71) than correlations between the GROC and change scores (−0.34 to −0.63) for all variables. The linear regression model including discharge scores explained a greater part of the variance of the GROC score (R2 = 0.63) than the model including change scores (R2 = 0.46). In both models, pain intensity was the variable most strongly associated with the GROC score. Conclusion Baseline and discharge outcome measures should be preferred over the GROC for measuring change after treatment in patients with CLBP.