Influence of non-steroidal anti-inflammatory drugs on the inflammatory sonographic features in erosive hand osteoarthritis: an intervention study

Objective The aim was to examine whether inflammatory US features in erosive hand OA patients change when discontinuing intake of NSAIDs before US examination in a non-randomized study. Methods Patients (n = 99) were allocated to the NSAIDs or control group according to their intake at baseline. US was performed at baseline (T0) and 2 weeks after discontinuation of NSAIDs (T1). Inflammatory features (i.e. synovial proliferation, effusion and power Doppler signal) were scored using a semi-quantitative scale (from zero to three). Pain levels were scored on a numerical rating scale. Binomial mixed models were fitted for US features, and odds ratios of having a US score of at least two vs at most one for synovial proliferation and effusion, and zero vs at least one for power Doppler were calculated. Results At baseline, both groups [NSAIDs group (n = 47) vs control group (n = 52)] were comparable for numerical rating scale pain, disease duration, number of radiographically affected joints, BMI and US baseline data, but not for age (P = 0.005). At T1, more synovial proliferation and power Doppler signal was seen compared with T0 in the NSAIDs group (P = 0.018 and 0.031, respectively). However, the interaction term time*NSAIDs was not found to be significant for any variable. The numerical rating scale pain at T1 was higher compared with baseline, although statistically non-significant. Conclusion No significant changes in inflammatory US features were seen in patients with erosive hand OA after withdrawal of NSAIDs for 2 weeks. This study suggests that an NSAID-free period is not necessary before assessing inflammatory disease activity in erosive hand OA.