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SAT0595-HPR Real-World Risk of Fall-Related Injuries among Rheumatoid Arthritis (RA) Patients Treated with Tumor Necrosis Factor Inhibitors (ANTI-TNFS) or Methotrexate (MTX)
  1. Y. Bao1,
  2. A. Ganguli1,
  3. G. De2,
  4. S. Kelkar2,
  5. J.R. Curtis3
  1. 1Health Economic and Outcomes Research, AbbVie, North Chicago
  2. 2Analysis Group Inc., New York
  3. 3University of Alabama at Birmingham, Birmingham, United States

Abstract

Background Structural damage and disease activity in RA patients may increase the risk of fall-related injuries (FRIs) due to limited mobility, impaired balance and postural instability.

Objectives To compare risks for FRIs between RA patients treated with anti-TNF therapies versus those treated with methotrexate (MTX) monotherapy in a real-world setting.

Methods Adults with ≥1 RA diagnosis (ICD-9 CM: 714.0) were identified in a large-scale U.S. claims database (OptumInsight, 1998-2011). Patients were stratified into treatment groups (anti-TNF and MTX group) based on their treatment history, irrespective of exposure to that treatment afterwards, similar to an intent-to-treat (ITT) approach. The anti-TNF group comprised new initiators with ≥1 claim for anti-TNFs, with or without MTX (index date defined as the date of the first anti-TNF claim). The MTX group comprised MTX users who were not eligible for the anti-TNF group and who filled ≥1 prescription for MTX (index date randomly selected). During the 6-month baseline period preceding the index date, patients in both groups were required to have continuous health plan enrollment and to be free of anti-TNF exposure. The primary study outcome was first hospitalization with FRI (ICD-9 CM: 800-829 and 850) after the index date. A secondary outcome was first use of any health care service (i.e. inpatient, out-patient, and emergency room) related to FRIs after the index date. Incidences for primary and secondary outcomes were described using Kaplan-Meier (KM) curves, and were compared between the treatment groups using multivariable Cox proportional hazard models adjusting for age, gender, Charlson comorbidity index, healthcare plan type, total RA-related costs and rates of FRIs during the baseline period.

Results A total of 11,894 patients were included in the anti-TNF group and 13,361 in the MTX group. Follow-up beyond 5 years was available for 2,011 and 1,104 patients, and median follow-up were 702 (1st quartile/Q1: 301, 3rd quartile/Q3: 1396) and 363 (Q1: 133, Q3: 882) days, respectively. The 5-year KM rates of hospitalizations with FRIs were 5.6% and 4.1% in the anti-TNF cohort and the MTX cohort, respectively. Based on the time-to-event analyses adjusting for baseline characteristics (including baseline FRIs), patients in the anti-TNF group were 21.3% less likely to incur a hospitalization with FRIs compared to patients in the MTX cohort (adjusted hazard ratio/HR: 0.79, 95% CI: 0.66–0.94, unadjusted HR: 0.69, 95% CI: 0.58–0.82). Moreover, patients in the anti-TNF cohort were 10.5% less likely to be diagnosed with FRIs at any place of service (adjusted HR: 0.90, 95% CI: 0.83–0.97, unadjusted HR: 0.84, 95% CI: 0.78–0.91) compared to patients in the MTX cohort.

Conclusions In this retrospective study of long-term, real-world outcomes, RA patients initiating anti-TNFs experienced a significantly lower risk of FRIs compared to patients receiving MTX.

Disclosure of Interest Y. Bao Shareholder of: AbbVie, Employee of: AbbVie, A. Ganguli Shareholder of: AbbVie, Employee of: AbbVie, G. De Employee of: Analysis Group, which has received consulting fee from AbbVie to partner on this research, S. Kelkar Employee of: Analysis Group, which has received consulting fee from AbbVie to partner on this research, J. Curtis Consultant for: AbbVie

DOI 10.1136/annrheumdis-2014-eular.1697

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