The added burden of depression in patients with osteoarthritis in Japan

Objectives: In Japan, osteoarthritis (OA) is a leading source of pain and disability; depressive disorders may limit patients' ability to cope with OA. This study examined the incremental effect of depression on the relationship between OA and health-related outcomes. Methods: Data from the 2014 Japan National Health and Wellness Survey (N=30,000) were collected on demographics, OA characteristics, and health characteristics of patients with OA. Depression symptoms were measured, and outcomes included health-related quality of life (HRQoL), work productivity and activity impairment, and health care resource utilization. Generalized linear regression models controlling for confounders were used to predict health-related outcomes. Results: Of 565 respondents with OA, 63 (11%) had symptoms of moderate or severe depression. In adjusted models, HRQoL remained lower among respondents with than without depression (p<0.001). Higher levels of presenteeism (mean±SE: 50%±9% vs 23%±2%) and activity impairment (mean±SE: 57%±7% vs 30%±1%) were observed for patients with than without depression (p<0.001); however, there were no differences for absenteeism (p=0.534). Patients with depression (vs no depression) reported more health care provider visits, emergency room visits, and hospitalizations (for all, p<0.001). Conclusion: Depression heightens the health-related burden of OA. Greater attention to depression among patients with OA is warranted.