Background A recent retrospective analysis of US insurance claims data suggested that, among patients newly diagnosed with RA, those who were anti-cyclic citrullinated peptide (anti-CCP) and/or rheumatoid factor (RF) positive (+) had increased RA-related healthcare costs over a 6-month post-diagnosis period compared with those who were anti-CCP/RF negative (–).1 Identification and treatment of this poor prognostic factor in the realm of RA diagnosis per the ACR guidelines appear to be of value.
Objectives To investigate the potential role of anti-CCP status in association with clinical outcomes and healthcare costs in conventional (c)DMARD-naïve patients with RA using real-world data.
Methods This was a retrospective, observational cohort study using the MarketScan® US administrative commercial claims and laboratory results databases. Patients included in this study had initiated cDMARD therapy between 1 January 2006 and 1 July 2014 (initiation=index), were aged ≥18 years at index, were continuously enrolled for 12 months before (baseline) and 12 months after (follow-up) index, did not receive cDMARDs or biologics during baseline, had an anti-CCP test result and had ≥2 medical claims with diagnoses of RA during baseline to 3 months after index. Patients were designated anti-CCP+ if their anti-CCP laboratory value was ≥20 IgG Ab units/mL. The study outcomes were all-cause and RA-related (i.e. medical claims with a diagnosis of RA or claims for cDMARDs and biologics) healthcare costs measured over the 12-month follow-up period. Generalized estimating equations were used to estimate the difference in healthcare costs from baseline to follow-up between anti-CCP+ and anti-CCP– patients (i.e. difference-in-difference [DiD]).
Results The study included 635 patients: 391 anti-CCP+ (mean age 52 years; 81% female); 244 anti-CCP– (mean age 52 years, 80% female). Anti-CCP+ and anti-CCP– patients differed substantially with respect to baseline all-cause healthcare costs (mean [SD] anti-CCP+: $7650 [$12,901], anti-CCP–: $12,591 [$23,922]; p<0.001), but not RA-specific costs (mean [SD] anti-CCP+: $809 [$2683], anti-CCP–: $891 [$2629]; p=0.239). In the DiD analysis, which adjusts for baseline differences between groups, anti-CCP+ patients experienced increases in all-cause total healthcare costs that were $2756 greater (p<0.001) than those of anti-CCP– patients; this result was primarily driven by greater increases in outpatient costs ($2274; p<0.001; Table). Analyses of RA-related healthcare costs were directionally consistent across the categories.
Conclusions After accounting for baseline differences between anti-CCP+ and anti-CCP– patients, anti-CCP+ patients' healthcare costs increased substantially more than anti-CCP– patients over a 12-month follow-up period. Among patients with RA who are newly initiating cDMARDs, anti-CCP positivity may serve as an identifiable predictor for markedly increased future healthcare costs, therefore establishing a need for a more appropriate treatment for cost reduction.
Johnston S, et al. J Manag Care Pharm 2015;21(Suppl. 10a):S69.
Disclosure of Interest S. Johnston Employee of: Truven Health Analytics; Truven Health Analytics was paid by Bristol-Myers Squibb to conduct this study, C. Patel Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb, K. Wilson Employee of: Truven Health Analytics, which was contracted by BMS to conduct this study, D. Spencer Grant/research support from: Bristol-Myers Squibb, L. Rosenblatt Shareholder of: Bristol-Myers Squibb, Employee of: Bristol-Myers Squibb