Assistant Professor Brown University School of Public Health, Providence, Rhode Island, USA Brown University Providence, United States
Background: Many different therapy options exist for the treatment and prevention of osteoporosis. Introduction of new therapeutic options, updates to practice guidelines, media coverage of adverse drug events, and healthcare policy changes have likely affected the use of these medications over time.
Objectives: To estimate the number of older adults with use of osteoporosis drugs and describe trends over time in Ontario, Canada, 1996-2022.
Methods: The Ontario Drug Benefit (ODB) program covers prescription drugs listed on the formulary for all residents aged 65 years or older. We leveraged pharmacy claims (ODB) data to identify all community-dwelling older adults (aged 66 or more years) with dispensed prescriptions for oral bisphosphonates (alendronate, etidronate, risedronate), intravenous bisphosphonate (zoledronic acid), denosumab, teriparatide, nasal calcitonin, or raloxifene (females only) between May 27, 1996 (date of earliest claim) and December 31, 2022. The number of patients with initial use (no prior exposure history) and any use of each medication was plotted by calendar year, and patient age was summarized using descriptive statistics.
Results: In total, we identified 712,036 unique community-dwelling older adults with use of an eligible osteoporosis medication during the study period (mean age=75.6 [standard deviation=7.2] years). Risedronate was the most common osteoporosis medication used, with 460,647 unique users, followed by alendronate (n=310,482), etidronate (n=303,620), and denosumab (n=193,104), and raloxifene (n=22,205). Teriparatide (n=233) and calcitonin (n=1,669) were the least commonly used osteoporosis medications, likely due to ODB formulary restrictions for these medications and calcitonin’s removal from the Canadian market in 2013. Large shifts were observed in the total number of users of any osteoporosis medication annually, from n=28,403 in 1997 to a peak of n=240,640 in 2009, then to n=200,912 in 2022. Shifts were especially large for denosumab (from n=12,580 in 2012 to a peak of n=114,778 in 2022) and etidronate (from a peak of n=126,478 in 2002 to virtually no users beyond 2017).
Conclusions: We observed major fluctuations in the number of users of osteoporosis medications over time that likely reflect changes in policy and clinical practice. Consideration must be given to the absolute number of users of each medication as well as time-trends when designing pharmacoepidemiologic studies in this population.