Low income, education levels tied to knee osteoarthritis

Socioeconomic status (SES), education level in particular, is correlated with the prevalence of knee osteoarthritis (OA), a recent study has found.

Researchers conducted a cross-sectional analysis of 9,071 participants (57.2 percent women) whose data were drawn from the fifth Korean National Health and Nutrition Examination Survey. SES was broken down into three components: education level, income level, and occupation.

The overall prevalence of radiographic knee OA was 36.3 percent. Stratifying by sex, a higher prevalence was seen in women than in men (44.8 percent vs 24.9 percent). Of all radiographic OA patients, 70.7 percent were women. Moreover, living in an urban area, higher education status, higher income level, and being in a managerial position were all linked to lower radiographic knee OA prevalence.

Groupings according to each SES component confirmed that in men and women, those in the lowest quartile of income and education level were more likely to have radiographic knee OA, knee pain, and knee stiffness than comparators in the top quartile. Participants in managerial work, including office and service jobs, had the lowest prevalence of knee symptoms, while those without jobs had the highest.

Multivariate logistic regression analysis revealed education level to be the strongest SES correlate of knee OA. Men (odds ratio [OR], 2.13, 95 percent confidence interval [CI], 1.38–3.286; p_trend<0.0001) and women (OR, 2.669, 95 percent CI, 1.713–4.158; p_trend<0.0001) with elementary education only were more than twice as likely to have knee OA vs counterparts with college education.

Income level remained a significant correlate in both sexes, as did occupation in women, but with much weaker magnitudes of effect.