Impact of comorbid conditions on health care expenditure and work-related outcomes in patients with rheumatoid arthritis

Objective To evaluate the impact of comorbid conditions on direct health care expenditure and work-related outcomes in patients with rheumatoid arthritis (RA). Methods This was a retrospective analysis of the Medical Expenditure Panel Survey from 2006 to 2015 in 4,967 adult RA patients in the USA. Generalised linear models were used for health care expenditure and income, logistic model for employment status, and zero-inflated negative binomial model for absenteeism. Thirteen comorbid conditions were included as potential predictors of direct cost and work-related outcomes. The models were adjusted for sociodemographic factors including sex, age, region, marital status, race/ethnicity, income, education and smoking status. Results RA patients with heart failure had the highest incremental annual health care expenditure (US$8,205; 95% CI, US$3,683-US$12,726) compared to those without the condition. Many comorbid conditions including hypertension, diabetes, depression, obstructive pulmonary disease, cancer, stroke and heart failure reduced the chance of RA patients aged between 18-64 years being employed. Absenteeism of employed RA patients was significantly affected by hypertension, depression, disorders of the eye and adnexa or stroke. On average, an RA patient with heart failure earned US$15,833 (95% CI, US$4,435- US$27,231) per year less than an RA patient without heart failure. Conclusion Comorbid conditions in RA patients were associated with higher annual health care expenditure, lower likelihood of employment, higher rates of absenteeism and lower income. Despite its low prevalence, heart failure was associated with the highest incremental health care expenditure and the lowest likelihood of being employed compared to other common comorbid conditions.