Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Comparison of Fracture Rates and Economic Outcomes by Age Group in Patients with Osteoporosis treated with Risedronate Enteric-Coated versus Immediate Release Bisphosphonates: A claims Data Analysis (#220)

Friederike Thomasius 1 , Santiago Palacios 2 , Asif Alam 3 , Mitra Boolell 3 , Rachel L Duckham 4 , Francis Vekeman 5 , Genevieve Gauthier 5
  1. Frankfurter Hormon und Osteoporosezentrum, , Frankfurt, Germany
  2. Palacios’ Institute of Women’s Health, Madrid, Spain
  3. Theramex, , London, United Kingdom
  4. Theramex, Sydney, NSW, Australia
  5. STATLOG, Montreal, Canada

Objective: Risedronate Enteric-Coated (EC) is the only oral-bisphosphonate which can be taken with food, while preserving a higher bioavailability compared to immediate-release risedronate. Whether this formulation can further reduce the risk of fracture when compared to other Immediate-Release Bisphosphonate (IRB) remains unclear. Thus this study compared fracture rates and economic outcomes between women with osteoporosis treated with EC vs. IRB.

Methods: Women with osteoporosis were selected from a large US claims database (2009-2019). Patients were classified into EC or IRB cohorts based on the treatment initiated on the index date (first dispensing date for an oral bisphosphonate), matched 1:1 based on demographic and clinical characteristics, and observed for ≥2 years. Incidence rates (IRs) of fractures and healthcare resource utilization per 1,000 patient-years were compared between cohorts using IR ratios (IRRs). Outcomes were assessed overall and by age-groups (<65 yrs, ≥65 yrs and ≥75 yrs).

Results: Cohorts (n=2,726, median age: 60.0 yrs) were observed on average 4.5 yrs. The IR of fractures was significantly lower in the EC vs. the IRB cohort for any fracture site (EC: 34.65, IRB: 42.13; IRR=0.83, p<0.05) and spine fractures (EC: 10.84, IRB: 15.13; IRR=0.71, p<0.05). When stratified by age-group results persisted (table). Across the observation period, the IR of fracture was lower in the EC vs. the IRB cohort, reaching statistical significance at 36-months (fracture rate; EC=7.08%; IRB=8.67%, p=0.04). IR of hospitalizations was lower in the EC vs. the IRB cohort (EC: 106.74, IRB: 124.20; IRR=0.86, p<0.05) leading to significantly lower hospitalization costs among EC patients (average per-patient-per-year; EC: US$3,611; IRB: US$4,603, p<0.05).

Conclusion: Women with osteoporosis treated with EC have a lower incidence of fracture when compared to IRB. Potentially indicating that the bioavailability and  therefore the efficacy of EC is higher than IRB, independent of food intake.

 

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