Oral Presentation ANZBMS-MEPSA-ANZORS 2022

Fracture risk in women with osteoporosis treated with gastro-resistant (ec) risedronate versus immediate release risedronate or alendronate: a claims data analysis in the United States (#8)

John Eisman 1 , Friedrike Thomasius 2 , Mitra Boolell 3 , Francis Vekeman 4 , Asif Alam 3 , Jason Heroux 4 , Bernard Cortet 5
  1. Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
  2. Rheumatology , Frankfurter Hormon Und Osteoporosezentrum, Frankfurt, Germany
  3. Medical Department, Theramex, London, UK
  4. Econometrics, STATLOG , Montreal, Quebec
  5. Service de rhumatologie, hôpital Roger-Salengro, CHU de Lille ; université Lille-2, Lille, France

Objective(s): Risedronate immediate release (Ris-IR) and delayed release (GR/EC) formulations and alendronate (Ale; IR formulation) are used by women with osteoporosis (OP) in the US. We compared risk of fractures between women on GR(EC) Ris and those on (a) IR Ris and (b) Ale.

Material and Methods: Women aged ≥ 60 yr with ≥ 2 oral bisphosphonate (OBPs) prescription fills with OP diagnosis and/or history of fracture were selected from a claims database (2009-2019). The index date and study cohorts (GR/EC Ris, IR Ris, Ale) were based on the first observed OBPs dispensing. All eligible women on GR/EC Ris were analyzed (N = 1,080). Comparator cohorts, randomly selected from women initiated on IR Ris and Ale to match the index year of women on GR/EC Ris. Adjusted incidence rate ratios (IRRs) were used to compare fracture risk between GR/EC Ris and IR Ris/Ale; and in women with high fracture risk.

Results: Women in the GR/EC Ris, IR Ris and Ale cohorts were followed for 3.0, 3.2, and 3.2 yr, respectively (mean age: 69, 69, and 70 yr). Unadjusted rates of any fracture per 1,000 women-yr were highest among women aged ≥70 yr (GR/EC Ris: 67 vs. 58 among women aged ≥65 yr, 60 among those at high risk with comorbidity/medications, and 51 among any GR/EC Ris; IR Ris: 97 vs. 88, 77, 65; Ale: 102 vs 87, 80, 67; respectively). Adjusted IRRs for GR/EC Ris vs IR Ris /Ale generally indicated lower risk of fracture for the GR/EC Ris (IRRs <1; Figure).

IRRs were statistically lower for GR/EC for pelvis fractures and for select fractures(Figure). 

Conclusions: Results suggest GR/EC Ris offers a lower risk of fracture than IR Ris or Ale among women with OP with higher baseline risk of fracture.

Disclosures: The study was funded by Theramex.

Figure. 6294801c81bbe-ANZBMS+graph.jpg