K N Hayes1,2, N He3,4, K A Brown5,4,6, A M Cheung5,7, D N Juurlink5,4,8, S M Cadarette5,3,4,9. 1. Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. k.hayes@mail.utoronto.ca. 2. Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada. k.hayes@mail.utoronto.ca. 3. Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, ON, M5S 3M2, Canada. 4. ICES, Toronto, ON, Canada. 5. Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. 6. Public Health Ontario, Toronto, ON, Canada. 7. Department of Medicine, University Health Network, University of Toronto, Toronto, ON, Canada. 8. Sunnybrook Research Institute, Toronto, ON, Canada. 9. Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.
Abstract
Most adherence studies only consider treatment following a first prescription. Using an extended follow-up, we found that 60% of seniors starting oral bisphosphonate therapy were exposed for ≥ 3 years (48% for ≥ 5 years). Studies are needed to examine the benefits and harms of continuing bisphosphonate therapy beyond 3 years. INTRODUCTION: The purpose of this study was to identify and describe patterns of long-term oral bisphosphonate use among seniors using a novel methodological approach that considers extended follow-up. METHODS: Among Ontarians aged 66 years or older, we identified subjects with a first dispensing of alendronate or risedronate between November 2000 and December 2016. We followed them until death or December 2019 to identify patients with ≥ 3 years of bisphosphonate use, defined as a proportion of days covered ≥ 80%, using 3-year rolling windows. We calculated the proportion of patients with long-term therapy (≥ 3 years of use) using Kaplan-Meier estimates. We described patterns of long-term use and compared patient characteristics between patients with and without long-term therapy. RESULTS: We identified 260,784 eligible seniors initiating bisphosphonate therapy. Of these, 60% continued therapy ≥ 3 years (77% women), and 48% continued ≥ 5 years. Characteristics did not meaningfully differ between patients with or without long-term therapy. The median length of long-term therapy was 7.0 (IQR 5.1) years for women and 6.1 (IQR 4.3) years for men. Only 20% experienced a treatment gap before long-term therapy, yet 50% experienced a treatment gap of ≥ 120 days after a median 5.3 years of therapy. Eighty-one percent who returned to therapy following a treatment gap re-initiated an oral bisphosphonate, with 18% switching to denosumab. CONCLUSIONS: Among seniors initiating oral bisphosphonates, we found that 60% receive at least 3 years of therapy when using an extended follow-up. Studies are needed to examine the benefits and harms of continuing bisphosphonate therapy beyond 3 years.
Most adherence studies only consider treatment following a first prescription. Using an extended follow-up, we found that 60% of seniors starting oral bisphosphonate therapy were exposed for ≥ 3 years (48% for ≥ 5 years). Studies are needed to examine the benefits and harms of continuing bisphosphonate therapy beyond 3 years. INTRODUCTION: The purpose of this study was to identify and describe patterns of long-term oral bisphosphonate use among seniors using a novel methodological approach that considers extended follow-up. METHODS: Among Ontarians aged 66 years or older, we identified subjects with a first dispensing of alendronate or risedronate between November 2000 and December 2016. We followed them until death or December 2019 to identify patients with ≥ 3 years of bisphosphonate use, defined as a proportion of days covered ≥ 80%, using 3-year rolling windows. We calculated the proportion of patients with long-term therapy (≥ 3 years of use) using Kaplan-Meier estimates. We described patterns of long-term use and compared patient characteristics between patients with and without long-term therapy. RESULTS: We identified 260,784 eligible seniors initiating bisphosphonate therapy. Of these, 60% continued therapy ≥ 3 years (77% women), and 48% continued ≥ 5 years. Characteristics did not meaningfully differ between patients with or without long-term therapy. The median length of long-term therapy was 7.0 (IQR 5.1) years for women and 6.1 (IQR 4.3) years for men. Only 20% experienced a treatment gap before long-term therapy, yet 50% experienced a treatment gap of ≥ 120 days after a median 5.3 years of therapy. Eighty-one percent who returned to therapy following a treatment gap re-initiated an oral bisphosphonate, with 18% switching to denosumab. CONCLUSIONS: Among seniors initiating oral bisphosphonates, we found that 60% receive at least 3 years of therapy when using an extended follow-up. Studies are needed to examine the benefits and harms of continuing bisphosphonate therapy beyond 3 years.
Entities:
Keywords:
Bisphosphonates; Epidemiology; Health services research; Osteoporosis; Pharmacoepidemiology; Practice patterns