FACTORS ASSOCIATED WITH DISEASE SEVERITY IN MEXICAN PATIENTS WITH RHEUMATOID-ARTHRITIS

Objective: To investigate clinical demographic, laboratory, and behavi oral variables associated with disease severity in rheumatoid arthriti s (RA). Methods: A case-control study was carried out in a tertiary ca re center. Participants were RA patients, 16 - 65 years of age, with a disease duration of greater than or equal to 2 years. Selection crite ria were established in advance. The sample size was calculated caking into account the prevalence of a low formal education level (< 6 year s of school) in a sample of 60 patients. Controls for each case were p aired according to age, sex, rheumatoid factor; and disease duration f or a case/control ratio of 1.1.8. Cases were defined as those patients having at least two of the following: failure to respond to greater t han or equal to 3 disease modifying anti-rheumatic drugs, score greate r than or equal to 3/10 on the Disability Index of the Health Assessme nt Questionnaire, and disease severity greater than or equal to 4/10 a s judged by the treating physician on a visual analogue scale. Control s were obtained from the same group but without such characteristics. All of the clinical charts were blindly evaluated for the clinical, de mographic, laboratory, and behavioral variables. Descriptive statistic s, univariate and multivariate analysis, odds ratios (OR) and 95% conf idence intervals (95% CI) were calculated. Results: We studied 46 case s and 82 controls. Univariate analysis showed that severity was associ ated with a low level of formal education (OR 3.15, CI 1.38-7.13), use of non-conventional therapy (OR 2.7, CI 1.34-5.49), treatment with or al steroids (OR 2.6, CI 1.28-6.8), compliance, and disease duration be fore a confirmed diagnosis of RA. These variables remained in the mult ivariate model. A low hemoglobin level and art increased platelet coun t were the biological variables associated with severity. Conclusions: The evaluation of RA must be conducted in a socio-cultural context si nce this is in some way linked to disease severity.