Fracture risk in women with osteoporosis initiated on gastro-resistant risedronate versus immediate release risedronate or alendronate: A claims data analysis in the USA
Publication Details
Eisman, J. A.,
Cortet, B.,
Boolell, M.,
Ionescu-Ittu, R.,
Vekeman, F.,
Heroux, J.,
&
Thomasius, F.
(2023).
Fracture risk in women with osteoporosis initiated on gastro-resistant risedronate versus immediate release risedronate or alendronate: A claims data analysis in the USA.
Osteoporosis International, 34.
Abstract
Summary: The study results indicate that women with osteoporosis initiated on gastro-resistant risedronate have a lower risk of fracture than those initiated on immediate release risedronate or alendronate. A large proportion of women discontinued all oral bisphosphonate therapies within 1 year of treatment start.
Purpose: Using a US claims database (2009–2019), we compared risk of fractures between women with osteoporosis initiated on gastro-resistant (GR) risedronate and those initiated on (a) immediate release (IR) risedronate or (b) immediate release alendronate.
Methods: Women aged ≥ 60 years with osteoporosis who had ≥ 2 oral bisphosphonate prescription fills were followed for ≥ 1 year after the first observed bisphosphonates dispensing (index date). Fracture risk was compared between the GR risedronate and IR risedronate/alendronate cohorts using adjusted incidence rate ratios (aIRRs), both overall and in subgroups with high fracture risk due to older age or comorbidity/medications. Site-specific fractures were identified based on diagnosis codes recorded on medical claims using a claims-based algorithm. Persistence on bisphosphonate therapy was evaluated for all groups.
Results: aIRRs generally indicated lower fracture risk for GR risedronate than IR risedronate and alendronate. When comparing GR risedronate to IR risedronate, statistically significant aIRRs (p<0.05) were observed for pelvic fractures in the full cohorts (aIRRs=0.37), for any fracture and pelvic fractures among women aged≥65 years (aIRRs=0.63 and 0.41), for any fracture and pelvic fractures among women aged≥70 years (aIRRs=0.69 and 0.24), and for pelvic fracture among high-risk women due to comorbidity/medications (aIRR=0.34). When comparing GR risedronate to alendronate, statistically signifcant aIRRs were observed for pelvic fractures in the full cohorts (aIRR=0.54), for any fracture and wrist/arm fractures among women aged≥65 years (aIRRs=0.73 and 0.63), and for any fracture, pelvic, and wrist/arm fractures among women aged≥70 years (aIRRs=0.72, 0.36, and 0.58). In all cohorts, ~40% completely discontinued oral bisphosphonates within 1 year. Conclusions Discontinuation rates of oral bisphosphonate therapy were high. However, women initiated on GR risedronate had a signifcantly lower risk of fracture for several skeletal sites than women initiated on IR risedronate/alendronate, particularly those aged≥70 years.> < 0.05) were observed for pelvic fractures in the full cohorts (aIRRs=0.37), for any fracture and pelvic fractures among women aged ≥ 65 years (aIRRs=0.63 and 0.41), for any fracture and pelvic fractures among women aged ≥ 70 years (aIRRs=0.69 and 0.24), and for pelvic fracture among high-risk women due to comorbidity/medications (aIRR=0.34). When comparing GR risedronate to alendronate, statistically significant aIRRs were observed for pelvic fractures in the full cohorts (aIRR=0.54), for any fracture and wrist/arm fractures among women aged ≥ 65 years (aIRRs=0.73 and 0.63), and for any fracture, pelvic, and wrist/arm fractures among women aged ≥ 70 years (aIRRs=0.72, 0.36, and 0.58). In all cohorts, ~40% completely discontinued oral bisphosphonates within 1 year.
Conclusions: Discontinuation rates of oral bisphosphonate therapy were high. However, women initiated on GR risedronate had a significantly lower risk of fracture for several skeletal sites than women initiated on IR risedronate/alendronate, particularly those aged ≥ 70 years.
Keywords
Osteoporosis, Gastric-resistant risedronate, Immediate release risedronate, Alendronate, Fracture rate, Persistence
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