Clinically relevant VAS pain score change in patients with acute rheumatic conditions

Abstract Introduction Pain assessment is a crucial step in the management of patients with rheumatic diseases. Among validated pain scores, the visual analog scale (VAS) score is the most widely used, in both clinical practice and therapeutic trials. Objective To determine the VAS pain score decrease that constitutes meaningful pain relief, with the goal of evaluating treatment effects. Methods We included patients with acute pain caused by non-malignant rheumatic conditions. Pain duration of less than 1 month and a baseline VAS score greater than 50/100 mm were required. Twice daily, patients evaluated pain intensity using the VAS and pain relief using a five-category verbal rating scale (VRS) where 0 indicated no pain relief and 4 excellent relief. Results Fifty patients were included. VAS score changes correlated linearly with VRS score changes ( r = 0.7 and P < 0.001). A one-category improvement on the VRS was associated with a 20-mm decrease in the VAS score ( P < 0.0001) and a two-category improvement with a 40-mm decrease ( P < 0.0003). Conclusion The dearth of published data on clinically relevant VAS pain score changes in patients with acute rheumatic pain requires further studies, in order to improve patient care and the comparability of therapeutic trials.