Prevalence of rheumatic regional pain syndromes in Latin-American indigenous groups: a census study based on COPCORD methodology and syndrome-specific diagnostic criteria

This study assessed the overall and specific prevalence of the main rheumatic regional pain syndromes (RRPS) in four Latin-American indigenous groups. A Community Oriented Program for Control of Rheumatic Diseases (COPCORD) methodology-based census study was performed in 4240 adults (participation rate: 78.88 %) in four indigenous groups: Chontal (Oaxaca, Mexico, n = 124), Mixteco (Oaxaca, Mexico; n = 937), Maya-Yucateco (Yucatan, Mexico; n = 1523), and Qom (Rosario, Argentina; n = 1656). Subjects with musculoskeletal pain were identified using a cross-cultural, validated COPCORD questionnaire administered by bilingual personnel, and reviewed by general practitioners or rheumatologists using standardized case definitions for the 12 most frequent RRPS. The overall prevalence of RRPS was confirmed in 239 cases (5.64 %, 95 % CI: 4.98–6.37). The prevalence in each group was Chontal n = 19 (15.32 %, 95 % CI: 10.03–22.69); Maya-Yucateco n = 165 (10.83 %, 95 % CI: 9.37–12.49); Qom n = 48 (2.90 %, 95 % CI: 2.19–3.82); and Mixteco n = 7 (0.75 %, 95 % CI: 0.36–1.53). In the whole sample, the syndrome-specific prevalence was rotator cuff tendinopathy: 1.98 % (95 % CI: 1.60–2.45); lateral epicondylalgia: 0.83 % (95 % CI: 0.59–1.15); medial epicondylalgia: 0.73 % (95 % CI: 0.52–1.04); biceps tendinopathy: 0.71 % (95 % CI: 0.50–1.01); anserine syndrome: 0.64 % (95 % CI: 0.44–0.92); inferior heel pain: 0.61 % (95 % CI: 0.42–0.90); trochanteric syndrome: 0.49 % (95 % CI: 0.25–0.64); de Quervain’s tendinopathy: 0.45 % (95 % CI: 0.29–0.70); trigger finger: 0.42 % (95 % CI: 0.27–0.67); carpal tunnel syndrome: 0.28 % (95 % CI: 0.16–0.49); Achilles tendinopathy (insertional): 0.12 % (95 % CI: 0.05–0.28); and Achilles tendinopathy (non-insertional): 0.07 % (95 % CI: 0.02–0.21). Leaving aside the comparison between Maya-Yucateco and Chontal groups (p = 0.18), we found significant differences (p < 0.001) in overall RRPS prevalence between the remaining pairs of indigenous groups. Syndrome-specific prevalences were also different between groups. Our findings support the hypothesis that overall RRPS prevalence and syndrome-specific prevalences are modulated by population-specific factors.