The association of disability and pain with individual and community socioeconomic status in people with hip osteoarthritis.

Objective: To examine associations between disability and socioeconomic status (SES) in persons with hip radiographic OA (rOA) or symptomatic OA (sxOA) in the Johnston County Osteoarthritis Project.

Methods: Cross-sectional analyses were conducted on individuals with hip rOA (708) or sxOA (251). rOA was defined as Kellgren-Lawrence ≥ 2. Educational attainment (<12 years or ≥12 years) and occupation (managerial or non-managerial) were individual SES measures. Census block group poverty rate (<12%, 12-25%, ≥25%) was the community SES measure. Disability was measured by the HAQ-DI and the WOMAC (function, pain, total). Covariates included age, gender, race, BMI, and presence of knee symptoms. Analyses examined associations of disability with each SES effect separately, followed by multivariable analyses using all SES variables, adjusting for covariates.

Results: In models with single SES variables adjusted for covariates, WOMAC scores were associated significantly (p<0.05) with low educational attainment and non-managerial occupation in rOA and sxOA. HAQ was significantly associated with low educational attainment in rOA and sxOA and with high community poverty in rOA. In models including all SES variables, the patterns of association were similar although with diminished significance. There was indication that education was more strongly associated with HAQ and WOMAC function, while occupation was more strongly associated with WOMAC pain.

Conclusion: Our data provide evidence that individual SES is an important factor to consider when examining disability and pain outcomes in older adults with hip OA.