Composite Autonomic Symptom Score 31 (COMPASS-31) for the assessment of symptoms of autonomic dysfunction in fibromyalgia.

Objectives: Autonomic dysfunction is a feature of fibromyalgia (FM). The Composite Autonomic Symptom Score-31 (COMPASS-31) is a validated tool to assess autonomic dysfunction. This study aimed to evaluate autonomic dysfunction in FM patients using COMPASS-31 and examine correlations with FM severity measures.

Methods: A cross-sectional study included women with FM and matched healthy controls. Participants completed COMPASS-31, the Revised Fibromyalgia Impact Questionnaire (FIQR), Polysymptomatic Distress Scale (PDS), Modified Fibromyalgia Assessment Status (FASmod), and PainDetect Questionnaire (PDQ). Correlations and severity analyses were performed.

Results: The study included 77 women with FM and 77 matched controls. Autonomic dysfunction was observed in 64.9% of FM patients and 3.5% of healthy controls. FM patients exhibited significantly higher COMPASS-31 scores (mean 47.03±17.27) compared to controls (21.55±11.48; p<0.00001). Internal consistency was good (Cronbach's α=0.74). A COMPASS-31 cut-off point of 38.28 (sensitivity 71.43%; specificity 91.86%; LR+ 8.78) distinguished FM patients from healthy controls. COMPASS-31 scores correlated positively with FIQR (rho=0.47, p<0.0001), PDS (rho=0.36, p<0.0001), FASmod (rho=0.32, p=0.004) and PDQ scores (rho=0.56, p<0.0001). Disease severity categories identified by FIQR were significantly associated with autonomic dysfunction symptoms (Kruskal-Wallis test: 18.77; p=0.00086).

Conclusions: This study highlights the high prevalence of autonomic dysfunction in FM and supports the utility of COMPASS-31 as a reliable tool for assessing autonomic symptoms in FM patients. Future research should explore the causality and the impact of FM severity on autonomic dysfunction through longitudinal studies.