Derivation and preliminary validation of an administrative claims-based algorithm for the effectiveness of medications for rheumatoid arthritis

Abstract

IntroductionAdministrative claims data have not commonly been used to study the clinical effectiveness of medications for rheumatoid arthritis (RA) because of the lack of a validated algorithm for this outcome. We created and tested a claims-based algorithm to serve as a proxy for the clinical effectiveness of RA medications.MethodsWe linked Veterans Health Administration (VHA) medical and pharmacy claims for RA patients participating in the longitudinal Department of Veterans Affairs (VA) RA registry (VARA). Among individuals for whom treatment with a new biologic agent or nonbiologic disease-modifying agent in rheumatic disease (DMARD) was being initiated and with registry follow-up at 1 year, VARA and administrative data were used to create a gold standard for the claims-based effectiveness algorithm. The gold standard outcome was low disease activity (LDA) (Disease Activity Score using 28 joint counts (DAS28) ≤ 3.2) or improvement in DAS28 by > 1.2 units at 12 ± 2 months, with high adherence to therapy. The claims-based effectiveness algorithm incorporated biologic dose escalation or switching, addition of new disease-modifying agents, increase in oral glucocorticoid use and dose as well as parenteral glucocorticoid injections.ResultsAmong 1,397 patients, we identified 305 eligible biologic or DMARD treatment episodes in 269 unique individuals. The patients were primarily men (94%) with a mean (± SD) age of 62 ± 10 years. At 1 year, 27% of treatment episodes achieved the effectiveness gold standard. The performance characteristics of the effectiveness algorithm were as follows: positive predictive value, 76% (95% confidence interval (95% CI) = 71% to 81%); negative predictive value, 90% (95% CI = 88% to 92%); sensitivity, 72% (95% CI = 67% to 77%); and specificity, 91% (95% CI = 89% to 93%).ConclusionsAdministrative claims data may be useful in evaluating the effectiveness of medications for RA. Further validation of this effectiveness algorithm will be useful in assessing its generalizability and performance in other populations.

Medication Effectiveness with the Use of Tumor Necrosis Factor Inhibitors Among Texas Medicaid Patients Diagnosed with Rheumatoid Arthritis

“…23 Curtis et al (2011) developed an algorithm to serve as proxy for evaluating the clinical effectiveness of RA medications using administrative claims data. 24 Based on this algorithm, a RA medication is classified as effective if it requires no increase in its dose or dosing frequency, no switching to (or addition of) new biologic or nonbiologic RA drugs, no more than 1 glucocorticoid (GC) joint injection, no increase in dose of a concurrent oral GC, and has high patient medication adherence. Although this algorithm has been validated, limited information exists in the literature regarding its use.…”

“…Although this algorithm has been validated, limited information exists in the literature regarding its use. 24,25 The objective of this study was to estimate the effectiveness of ADA, ETN, and IFX among RA patients using the comparative effectiveness algorithm designed by Curtis et al for large retrospective databases. 24 R heumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints.…”

“…24,25 The objective of this study was to estimate the effectiveness of ADA, ETN, and IFX among RA patients using the comparative effectiveness algorithm designed by Curtis et al for large retrospective databases. 24 R heumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints. 1 RA is a leading cause of disability and affects about 1% of the adult U.S. population with a higher prevalence, incidence, and lifetime risk in women compared with men.…”

“…24 Based on the algorithm, a RA medication was classified as effective in a particular patient if all the of following criteria were met:…”

“…The study time frame was from July 2003 to August 2011, and prescription and medical claims for each subject were analyzed over an 18-month period (6 months pre-and 12 months post-index). Based on a RA medication effectiveness algorithm (Curtis et al 2011), a RA medication was classified as effective if each of the following 6 criteria were met: (1) high medication adherence (i.e., medication possession ratio [MPR] ≥ 80%, defined as the sum of days' supply for all fills or infusions divided by the number of days in the study period); (2) no switching to (or addition of) new biologic RA drugs; (3) no addition of new nonbiologic RA drugs; (4) no increase in dose or frequency of administration of the RA medication currently evaluated; (5) no more than 1 glucocorticoid (GC) joint injection; and (6) no increase in dose of a concurrent oral GC. Propensity score (PS) matching was employed, and paired tests (i.e., McNemar's) and multivariate conditional logistic regression analysis were used to compare groups.…”