Costs and predictors of costs in rheumatoid arthritis: A prevalence‐based study

Objective To analyze the annual cost of rheumatoid arthritis (RA) and its predictive factors. Methods Data were obtained from a 12‐month retrospective cohort of 201 RA patients, randomly selected from a rheumatology registry, through a structured interview and records of the Central Information System of the hospital. Results were divided into direct, indirect, and total costs in 2001 US dollars. A sensitivity analysis was performed. Multiple linear regression models for the different types of costs were carried out. Results The total cost was $2.2 million per year, with a cost attributable to RA of $2.07 million per year. The average cost per patient was $10,419 per year (ranging from $7,914 per patient per year in the best scenario to $12,922 per patient per year in the worst case). Direct costs represent nearly 70% of total costs. We found an average increment in total costs of $11,184 per year per unit of Health Assessment Questionnaire (HAQ) score ( P < 0.0001) and an average annual increment of $621 per year of disease ( P < 0.0001). After adjustment, the HAQ score, inability to perform housework tasks, and being permanently disabled for work were the only predictors of high costs. Conclusion Our data show a remarkable economic impact of RA over society and link the costs of the disease to its consequences in terms of functional disability, work disability, and housework disability.