Economic Burden of Patients with Inadequate Response to Targeted Immunomodulators for Rheumatoid Arthritis

BACKGROUND: Targeted immunomodulators (TIMs), including biologic disease-modifying antirheumatic drugs (DMARDs) and JAK/STAT inhibitors, are effective therapies for rheumatoid arthritis (RA), but some patients fail to respond or lose response over time. This study estimated the real-world prevalence of RA patients with inadequate responses to an initial TIM (nonresponders) in the United States and assessed their direct and indirect economic burden compared with treatment responders. METHODS: Administrative claims data (January 1999-March 2014) from a large private-insurer database were used, which included work-loss data from a subset of reporting companies. Eligible patients (classified as responders and nonresponders) had ≥ 1 claim for a TIM approved for the treatment of RA and ≥ 2 RA diagnoses in the claims history, with continuous pharmaceutical and medical benefit eligibility for 6 months before (baseline) and 12 months after (study period) the date of the first TIM claim (index date). All-cause and RA-related health care resource use (HCRU) and costs, work loss, and indirect costs during the study period were compared for responders versus nonresponders. Multivariable regression was used to adjust for baseline covariates. Sensitivity analyses of HCRU and direct costs were conducted for patients with index dates before and after 2008 to account for different approval dates of TIMs. RESULTS: Of 7,540 eligible patients with RA, 2,527 (34%) were classified as responders, and 5,013 (66%) were classified as nonresponders; 407 and 723 had work-loss data, respectively. After adjusting for baseline covariates, nonresponders had significantly higher HCRU, including inpatient admissions (incidence rate ratio [IRR] = 1.94), outpatient visits (IRR = 1.19), emergency department visits (IRR = 1.53), and number of prescription fills (IRR = 1.09; all, P < 0.001). Nonresponders also had significantly higher adjusted all-cause ($12,868 vs. $9,621, respectively) and RA-related ($5,740 vs. $4,495; both, P < 0.001) medical costs compared with responders. In addition, nonresponders reported significantly more days of work lost compared with responders (22.1 vs. 16.7 days, respectively; IRR = 1.21; P = 0.007) and higher indirect costs ($3,548 vs. $2,890; P = 0.002). Sensitivity analyses of HCRU and direct costs by index date (before and after 2008) were consistent with the full sample. CONCLUSIONS: A large portion of patients with RA had inadequate responses to their initial TIM therapy with significantly higher economic burden, including higher HCRU, medical costs, and indirect costs due to work loss, compared with TIM therapy responders.