Adalimumab, etanercept, and infliximab utilization patterns and drug costs among rheumatoid arthritis patients.
ABSTRACT To evaluate the utilization patterns of the anti-tumor necrosis factor (anti-TNF) agents Humira (adalimumab), Enbrel (etanercept), and Remicade (infliximab) in patients with rheumatoid arthritis (RA) and compare medication costs during the first year of treatment. (Humira is a registered trademark of Abbott Laboratories, IL; Enbrel is a registered trademark of Immunex Corporation, CA; and Remicade is a registered trademark of Janssen Biotech, Inc., PA).
This retrospective analysis of medical and pharmacy claims included patients who were aged ≥18 years, had ≥2 RA diagnosis codes, and had ≥365 days of persistence with the index anti-TNF. Patients excluded had claims for anti-TNF agents within 6 months before the index date. Refill patterns for adalimumab and etanercept, number of infliximab infusions, time between infusions, and dose per infusion were analyzed for 12 months. Direct anti-TNF medication costs were compared among anti-TNFs for the initial treatment year.
Infliximab-treated patients (n = 457) were significantly older than adalimumab- (n = 337) or etanercept-treated patients (n = 902). Time between refills was longer than recommended for 28% and 30% of adalimumab and etanercept refill periods, respectively. Potential cumulative time without therapy was 33 days for adalimumab and 43 days for etanercept. Statistically significant differences in mean per-patient anti-TNF medication costs for the first year were reported for adalimumab, etanercept, and infliximab ($14,991, $13,361, and $18,139, respectively; p < 0.0001); however, a cost assessment using labeled dosing of the anti-TNF agents with optimal treatment compliance yielded comparable annual medication costs.
This analysis only evaluated utilization patterns for selected anti-TNF agents and was not inclusive of other medications that patients may have been using for RA. Absolute patient adherence could not be assessed due to lack of information on how patients were self-administering adalimumab and etanercept or if samples of the agents were made available.
This study identified gaps in patients' refills compared with prescriber recommendations. The infliximab-treated group had infusion patterns consistent with prescribing information. Potential clinical and economic implications of dose attenuation with adalimumab and etanercept should be explored further.
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ABSTRACT: Comorbidity (CM) is a powerful predictor of health outcome and cost, as well as an important confounder in many epidemiologic studies. However, choosing the most appropriate CM measurement instrument is difficult because comparative data on how the available instruments perform in various disease settings are limited. We collected CM data (from the complete medical records) for two population-based prevalence cohorts with rheumatoid arthritis (RA) and osteoarthritis (OA) and a comparison cohort without arthritis (NA), using two different CM instruments: the Charlson CM index (Charl), which is based on 17 diagnoses each weighted by mortality risk, and the Index of Coexistent Diseases (ICED), which estimates the severity and frequency of 14 comorbid conditions and provides an assessment of the impairment or disability caused by each. Cox proportional hazards modeling was used to assess the impact of the two types of comorbidity scores (Charl and ICED) on survival after prevalence (index) date, adjusting for the age, sex, and disease status. There were 450, 441, and 889 individuals in the RA, OA, and NA groups, respectively, with a mean follow-up period of 10.6 years. During the follow-up, 293, 307, and 546 deaths occurred in the RA, OA, and NA groups, respectively. The mean age and percent females were: 63.3 years, 74%; 70.7 years, 74%; and 67.5 years, 75% for the RA, OA, and NA groups, respectively. Comorbidity was highest in RA, intermediate in OA, and lowest in NA by both Charl and ICED. Cox proportional hazards modeling demonstrated that both Charl and ICED were highly statistically significant predictors of mortality (P<0.0001) after adjusting for age, sex, and disease state (RA, OA, or NA) and that ICED remained highly significant as a predictor of mortality, even after adjusting for Charl. We conclude that estimating CM from medical records using ICED, an instrument that incorporates an assessment of impairment and disability, is feasible and that such as assessment provides information that independently predicts mortality, even after adjusting for the results of traditional diagnosis-based CM measures, such as Charl.Journal of Clinical Epidemiology 12/1999; 52(12):1137-42. · 5.33 Impact Factor
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ABSTRACT: Variability in dosing and costs of biologics among patients with rheumatoid arthritis (RA) is of interest to healthcare descision-makers. We examined dosing and costs among RA patients newly treated with infliximab or etanercept under conditions of typical clinical practice. Integrated pharmacy and medical claims data were obtained from 61 U.S. health plans. RA patients newly treated with infliximab or etanercept between July 1999-June 2002 were selected. A maintenance number of infliximab vials was determined after the "loading period" (2-3 infusions); those with >or= 2 occurrences of an increase in vials or an interval between infusions of <49 days were considered to have had escalated. For etanercept patients, escalation was based on >or= 2 instances of increased average daily dose. Multiple logistic regression analyses were conducted to assess variables associated with dose escalation. RA-related costs at one year post-initiation also were examined; comparisons were made using generalized linear models. A total of 1,548 patients were identified (n = 598 and 950 for infliximab and etanercept respectively). Infliximab recipients were somewhat older (50.5 vs. 46.6 years for etanercept). Nearly 60% of infliximab patients increased their dose at one year, compared to 18% for etanercept. Infliximab patients who escalated dose incurred a 25% increase in mean one-year costs (20,915 dollars vs. 16,713 dollars for no increase; p < 0.0001). Costs among etanercept patients did not substantially differ based on dose escalation (14,482 dollars vs. 13,866 dollars respectively). Infliximab is associated with higher rates of dose escalation relative to etanercept, which contributes to substantially higher one-year medical costs.BMC Musculoskeletal Disorders 11/2004; 5(1):36. · 1.88 Impact Factor
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ABSTRACT: To observe the course of the disease activity in rheumatoid arthritis (RA) patients treated with the standard infliximab dosing regimen and to adjust treatment guided by the pattern of disease activity. All RA patients starting infliximab treatment were included and observed for at least 37 weeks. At infusion 4 (week 14), European League Against Rheumatism response was assessed. In moderate responders the dose was unchanged and the disease activity was carefully observed. In case of stable disease activity, the dose was increased at infusion 5 (week 22). In case of a temporary response the interval was reduced. Paired t-testing was applied to the disease activity score with 28-joint counts (DAS28) at week 22 and study endpoint. A total of 76 patients were included. Response after 14 weeks: good 22 (29%) patients, moderate 26 (34%) patients, and non-response in 21 patients. Seven patients (9%) dropped out before week 14 due to adverse events (5) or patients' initiative (2). In patients with moderate response, the following disease course between infusion 4 and 5 was observed: improvement to good response 6, temporary response 6, stable disease activity 6, drop out 8. In moderate responders, interval reduction and dose increase resulted in a decrease in mean DAS28 from 5.1 to 3.6 [P = 0.005, mean interval 5.6 weeks, mean infliximab dose 4.8 mg/kg/8 week (endpoint)] and from 4.1 to 3.6 [P = 0.04, mean infliximab dose 7.3 mg/kg/8 week (endpoint)], respectively. Three different patterns of disease activity were observed in moderate responders after 14 weeks of infliximab treatment, i.e. further improvement, no change in disease activity or a temporary response. Both interval reduction and dose increase significantly reduced disease activity, however, with different mean infliximab dosages. In good responders the response was often sustained over follow-up, whereas non-responders showed modest or no improvement despite dose adjustments.Rheumatology 02/2007; 46(1):146-9. · 4.21 Impact Factor