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

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 1month and a baseline VAS score greater than 50/100mm 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.