Socioeconomic Disparities in Osteoporosis Prevalence: Different Results in the Overall Korean Adult Population and Single-person Households

Objectives: The present study was conducted in order to examine the association between socioeconomic status (SES) and osteoporosis prevalence in Korea and to assess whether different associations are found in single-person households. Methods: A cross-sectional population-based study was conducted using the Korea National Health and Nutrition Examination Survey, from 2008 to 2011. The study subjects were people aged ${\geq}50$ years with osteoporosis as defined by bone mineral density. Multivariate logistic models were used to estimate prevalence odds ratios (pORs) and 95% confidence intervals (CIs). Gender differences in the likelihood of osteoporosis were analyzed based on household income, education level, and residential area. Results: There were 8221 osteoporosis patients aged ${\geq}50$ years, of whom 927 lived in single-person households. There was a gender-specific association between osteoporosis prevalence and all three SES factors that we analyzed: income, education, and residential area. After adjusting for age, SES, and health behaviors, including body mass index (BMI), low household income was only significantly associated with osteoporosis in men, whereas education level had an inverse relationship with osteoporosis only in women (p=0.01, p<0.001, respectively). However, after controlling for age and BMI, rural residency was only associated with osteoporosis in women living in single-person households (pOR, 1.59; 95% CI, 1.05 to 2.43). Conclusions: The Korean adult population showed a gender-specific relationship between SES and osteoporosis prevalence, with a different pattern found in single-person households.