Rheumatoid Arthritis Prevalence and Risk Factors in Korean Adults: A Focus on Age and Sex Differences

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that affects the joints, causing swelling, pain, stiffness, and functional decline. This study aims to clarify the prevalence and risk factors of RA based on sex and age among Korean adults, providing essential data for targeted prevention and management strategies. We analyzed data from the Korea National Health and Nutrition Examination Survey 2016-2021, comprising 25,166 participants aged 20 and older. Sociodemographics, health status, and behavior factors were evaluated, with RA defined based on self-reported diagnosis. A complex sampling design was utilized to ensure representative results and multiple logistic regression was employed to determine the risk factors linked to RA. The overall prevalence of RA among Korean adults was 1.1%, showing a significant sex-based disparity: 0.6% and 1.7% in men and women, respectively. RA prevalence increased with age, peaking at 3.5% in individuals over 70. This study identified education level, subjective health status, and age as key predictors of RA. Among men, significant predictors of RA included education level and subjective health status, with a higher risk observed in men with only elementary education and poor perceived health. For women, age and subjective health status were the main risk factors, with RA risk increasing markedly in older age groups, particularly in those aged 70 and above. This study highlights the distinct prevalence and risk factors for RA among Korean adults by sex and age. Key predictors-education level, subjective health status, and age-suggest that tailored health interventions addressing these factors are crucial to reducing the RA burden and enhancing health outcomes among affected populations.