Background/Purpose: Many studies have explored the economic burden of established RA but few data are available about the determinants of costs in early rheumatoid arthritis (RA) cared in real life settings.

The present study aims to describe the determinants of medical costs of early RA during the first 4 years of the disease.

Methods: The ESPOIR cohort is a nationwide cohort that enrolled 813 patients with early arthritis, highly suspect of RA¹, between 2002 and 2005. Data were collected every six months during the first two years then every year. The health resource use was investigated using a validated questionnaire collecting consultations to medical doctors or health professionals, clinical workups, hospitalizations, and treatments. Costs of care (direct costs) were elicited using the national average prices (2007 euros). 

After log-transformation of costs, their determinants were explored by multilevel modeling, using unconditional means models to test for structural effects. To investigate the impact of treatment strategies, patients were classified according to time of biologic initiation: “first-year” (n = 42), “later year” (n = 66) and “never” (n = 440). Univariate correlations were first tested (p ≤ 0.05) so as to preselect a set of variables for multivariate analyses. Then, a multilevel regression analysis was conducted to identify determinants of total direct costs during the first 4 years of follow-up.

Results: Complete data were available for 548 patients (mean age 56 yrs, female 77%, ACPA 46%, RF 50%, ACR/EULAR 2010 83%, mean DAS28 5.1, mean HAQ 1) . Annual mean direct cost per patient was €3,648, with a range from €18 to €53,739. On average, RA drug costs represented 48% of the overall direct costs, and up to 76% for patients receiving biologics.

With respects to total costs, living with a partner and baseline physician certainty of RA diagnosis less than 50% were each associated with lower total costs. Higher baseline HAQ score, increase in HAQ score ³ 0.25 between baseline and the 6-month study visit, and positive rheumatoid factor were associated with higher total costs. In addition, the greatest increases in total costs were associated with “first year” use and “later year” use with approximately 9 and 5-fold increases in total costs, respectively (Table below). Patient socioeconomic status had no impact on total medical costs.

Conclusion: As in established RA, biologic use is the main cost driver in rheumatoid arthritis care within the first years of the disease.

1: Combe B and Al. The ESPOIR cohort: a ten-year follow-up of early arthritis in France: methodology and baseline characteristics of the 813 included patients. Joint Bone Spine 2007;74(5):440-5.