Health-Related Quality of Life in Older Adults with Rheumatoid Arthritis: A Sex-Specific Case-Control Analysis of Physical and Mental Health Domains

Abstract

Background: The impact of rheumatoid arthritis (RA) on health-related quality of life (HRQoL) in older adults remains incompletely characterized, particularly regarding sex-specific patterns and the relative contribution of physical and mental health domains in later life. Methods: We conducted an observational cross-sectional case–control analysis including adults aged ≥65 years. A total of 180 patients with RA (65.6% women) were compared with 195 age- and sex-matched control subjects. HRQoL was assessed using the Short Form-12 (SF-12) questionnaire, generating Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. Analyses were stratified by sex. Associations between HRQoL domains and clinical variables were examined using correlation analyses and sex-specific multivariable linear regression models. Effect sizes (Cohen’s d) were calculated to quantify the magnitude of between-group differences. Results: Women with RA showed significantly lower SF-12 physical (PCS) and mental (MCS) component scores than men with RA, indicating a greater impairment in overall HRQoL. Women also exhibited higher functional disability, as assessed by the Health Assessment Questionnaire (HAQ), and higher disease activity, as assessed by DAS28. In sex-stratified case–control comparisons, men with RA showed lower SF-12 PCS scores, while MCS scores were comparable to those of the age-matched male controls. In contrast, women with RA exhibited significantly lower PCS and MCS scores compared to age-matched female controls. In multivariable analyses, distinct sex-specific patterns were observed. In women with RA, HAQ emerged as the only independent determinant of PCS, whereas DAS28 was the sole independent determinant of MCS. In men with RA, PCS was independently associated with DAS28, whereas MCS was independently associated with HAQ. Effect size analyses indicated consistently small impairments in both physical and mental HRQoL domains in women, whereas in men, the impact was small and largely confined to the physical domain. Conclusions: In older adults with RA, HRQoL impairment is sex-dependent and domain-specific, with women experiencing a more pronounced and generalized reduction in both physical and mental health compared with men. Sex-specific differences in the relative contribution of disease activity and functional disability highlight the need for a differentiated interpretation of patient-reported outcomes in this population. A domain-specific and sex-aware assessment of HRQoL may enhance the clinical evaluation of older patients and provide a more comprehensive understanding of disease burden beyond inflammatory activity alone.