A community-based study on the prevalence of spondyloarthritis and inflammatory back pain in Mexicans.

BACKGROUND: The prevalence of spondyloarthritis (SpA) varies across populations. In Mexicans, the prevalence of SpA is still unknown. OBJECTIVE: The objective of this study was to determine the prevalence of SpA in the community as well as that of inflammatory back pain (IBP) and ankylosing spondylitis (AS). METHODS: We identified individuals older than 18 years with nontraumatic back pain (BP) in a door-to-door nurse survey using the Community Oriented Program for the Control of Rheumatic Diseases. Then, general physicians and rheumatology fellows selected those likely to have IBP (Berlin criteria). Finally, 2 expert rheumatologists assessed IBP individuals according to clinical data and classification criteria and requested HLA-B27 and radiographic studies to determine the clinical condition of the individual and SpA (European SpA Study Group) classification. RESULTS: The prevalence of BP among 4059 individuals was 14.6% (95% confidence interval [CI], 13.6-15.8). The prevalence of IBP and SpA was 1.3% (95% CI, 1.0-1.7) and 0.6% (95% CI, 0.4-0.9), respectively. Ankylosing spondylitis prevalence was 0.1% (95% CI, 0.02-0.2). Inflammatory back pain and SpA percentage of males and females was similar. The percentage of individuals with IBP according to the 2 experts was lower than that determined by general physicians and rheumatology fellows, but all cases with HLA-B27, radiographic sacroiliitis, SpA, and AS had previous IBP confirmation by the expert. CONCLUSIONS: The prevalence and sex distribution of patients classified with SpA in this community study--as well as that of patients diagnosed with AS--are consistent with those found in recent studies. Expert assessment of individuals with positive responses to questionnaires is relevant for the classification of IBP and SpA.

Prevalence of back pain in the community. A COPCORD-based study in the Mexican population.

OBJECTIVE: Back pain (BP) is frequent in the community; its prevalence in México is 6%. Our objective was to determine the prevalence of BP in Mexican communities and determine its most important characteristics. METHODS: A cross-sectional study of individuals aged > 18 years was conducted in Mexico City and in urban communities in the state of Nuevo León. Sampling in Mexico City was based on community census and in Nuevo León, on stratified, balanced, and random sampling. Procedures included a door-to-door survey, using the Community Oriented Program for the Control of Rheumatic Diseases, to identify individuals with BP > 1 on a visual analog scale in the last 7 days. General practitioners/rheumatology fellows confirmed and characterized BP symptoms. RESULTS: In all, 8159 individuals (mean age 43.7 yrs, two-thirds female) were surveyed and 1219 had BP. The prevalence of nontraumatic BP in the last 7 days was 8.0% (95% CI 7.5-8.7). The mean age of these individuals was 42.7 years, and 61.9% were female. Thirty-seven percent had inflammatory BP [prevalence of 3.0% (95% CI 2.7-3.4)]. Compared with the state of Nuevo Léon, the characteristics and consequences of BP in Mexico City were more severe. In logistic regression analysis, living in Mexico City, having a paid job, any kind of musculoskeletal pain, high pain intensity, and obesity among other variables were associated with BP. CONCLUSION: The prevalence of nontraumatic BP in the last 7 days in urban communities in México is 8.0%. However, clinical features and consequences differed among the communities studied, suggesting a role for local factors in BP.