Correlation of Fibromyalgia Survey Questionnaire and Quantitative Sensory Testing Among Patients With Active Rheumatoid Arthritis

Objective. Patients with rheumatoid arthritis (RA) commonly demonstrate disordered pain processing associated with high pain sensitization. Pain sensitization is often assessed using quantitative sensory testing (QST), which is burdensome to patients. The self-administered Fibromyalgia Survey Questionnaire (FSQ) has been proposed as a low-burden, surrogate measure of central pain sensitization. We examined the correlation between FSQ and QST in patients with active RA. Methods. Participants in the Central Pain in Rheumatoid Arthritis (CPIRA) cohort underwent FSQ and QST evaluation at enrollment. QST measures included pressure pain threshold (PPT) at the thumb, trapezius, wrist, and knee; temporal summation (TS) at the wrist and arm; and conditioned pain modulation (CPM). Partial Spearman correlation between FSQ and each QST measure was assessed, adjusted for demographic factors, study site, disease characteristics, and pain catastrophizing. Sensitivity analyses included (1) stratified analysis by sex and (2) evaluation of how each component of FSQ associates with the QST measures. Results. Among 285 participants with active RA, FSQ was weakly but statistically significantly correlated with PPT (r range = -0.31 to -0.21), and TS (r range = 0.13-0.15) at all sites in unadjusted analyses. After adjustment, statistically significant correlations persisted for TS at the wrist and PPT at all sites (except the thumb). Sensitivity analyses did not identify differences in association based on sex or with individual FSQ components. Conclusion. FSQ and QST were correlated among participants with active RA, but the strength of association was weak. QST and FSQ are not interchangeable measures of pain sensitization.