Validity and Agreement of the Thai Self-Reported Questionnaire Based on the Acttion-Aps Pain Taxonomy Fibromyalgia Diagnostic Criteria in Patients With Chronic Musculoskeletal Pain

Background: Fibromyalgia (FM) is a chronic widespread pain syndrome that leads to functional impairment and poor quality of life. The American College of Rheumatology (ACR) diagnostic criteria, introduced in 2016, have been widely used. However, the ACTTION-American Pain Society Pain Taxonomy (AAPT) group introduced new, shorter criteria in 2018 to simplify the diagnosis. The FM self-administered questionnaire (FSQ), based on the ACR 2016, had good validity; however, studies on the shorter and more user-friendly AAPT criteria were needed. Objectives: This study aimed to develop a Thai version of the short AAPT criteria for the FM self-administered questionnaire (AAPT-FSQ) and to assess its validity and agreement with the ACR 2016. Methods: AAPT criteria were translated into Thai. Of the 128 patients with chronic musculoskeletal pain for more than three months at the Rehabilitation Medicine outpatient clinic were asked to complete a self-questionnaire that included the Thai AAPT-FSQ, Thai Fatigue Severity Scale (FSS), and Thai Pittsburgh Sleep Quality Index (PSQI). Lastly, FM diagnosis for each participant was done by physiatrists based on the ACR 2016 diagnostic criteria. Results: Construct validity showed strong correlations between AAPT pain sites and Widespread Pain Index (rs = 0.78, p < 0.001); AAPT sleep problems and Thai PSQI (rs = 0.64, p < 0.001), and AAPT fatigue problems and Thai FSS (rs = 0.67, p < 0.001). Diagnosis agreement between the AAPT and ACR 2016 criteria was 90.6%, with a substantial Kappa coefficient of 0.67 (p < 0.001), indicating good concordance. The sensitivity and specificity were 48.3% (95% CI: 29.4%–67.5%) and 99.0% (95% CI: 94.5%–100.0%), respectively. Conclusion: The Thai AAPT-FSQ had good construct validity and agreement in patients with chronic musculoskeletal pain. Due to its shorter criteria and simplicity, it may serve as a practical self-administered questionnaire for FM.