STUDY DESIGN: Assessment of correlation of measures of low back pain (LBP) using data pooled from 2 identical studies. OBJECTIVE: To assess the relative responsiveness of and correlation between various measures of LBP, including the Roland-Morris Disability Questionnaire (RMDQ), the LBP intensity (LBPI) visual analog scale (VAS), and patient's global assessment of response to therapy (PGART). SUMMARY OF BACKGROUND DATA: Several tools are available to measure pain, functional limitation, and response to therapy for LBP. Studies have shown varying degrees of responsiveness and correlation. METHODS: This was a pooled subgroup analysis of patients with chronic LBP from 2 identical studies comparingetoricoxib 60 mg, 90 mg, and placebo. LBP was assessed by the time-weighted average change from baseline over 12 weeks as measured by RMDQ, LBPI VAS, and PGART. Correlation was calculated using Pearson's correlation coefficient. RESULTS: The correlation (r) between LBPI and RMDQ changes ranged from 0.657 and 0.703; correlations between LBPI and PGART changes ranged from 0.677 and 0.738. Cutpoints separating responders from nonresponders for all 3 measures fell near the 66.7th percentile of response and were consistent with minimal clinically significant changes identified in the literature. CONCLUSION: In this study, the RMDQ, LBPI VAS, and PGART showed a high degree of correlation in measuring response to therapy in LBP, suggesting clinicians may be able to simplify assessments.
RCT Entities:
STUDY DESIGN: Assessment of correlation of measures of low back pain (LBP) using data pooled from 2 identical studies. OBJECTIVE: To assess the relative responsiveness of and correlation between various measures of LBP, including the Roland-Morris Disability Questionnaire (RMDQ), the LBP intensity (LBPI) visual analog scale (VAS), and patient's global assessment of response to therapy (PGART). SUMMARY OF BACKGROUND DATA: Several tools are available to measure pain, functional limitation, and response to therapy for LBP. Studies have shown varying degrees of responsiveness and correlation. METHODS: This was a pooled subgroup analysis of patients with chronic LBP from 2 identical studies comparing etoricoxib 60 mg, 90 mg, and placebo. LBP was assessed by the time-weighted average change from baseline over 12 weeks as measured by RMDQ, LBPI VAS, and PGART. Correlation was calculated using Pearson's correlation coefficient. RESULTS: The correlation (r) between LBPI and RMDQ changes ranged from 0.657 and 0.703; correlations between LBPI and PGART changes ranged from 0.677 and 0.738. Cutpoints separating responders from nonresponders for all 3 measures fell near the 66.7th percentile of response and were consistent with minimal clinically significant changes identified in the literature. CONCLUSION: In this study, the RMDQ, LBPI VAS, and PGART showed a high degree of correlation in measuring response to therapy in LBP, suggesting clinicians may be able to simplify assessments.
Authors: Gustavo C Machado; Chris G Maher; Paulo H Ferreira; Marina B Pinheiro; Chung-Wei Christine Lin; Richard O Day; Andrew J McLachlan; Manuela L Ferreira Journal: BMJ Date: 2015-03-31