Rate of Osteoporosis Drug Treatment to Prevent Recurrent Fractures Dropping

Allison Inserro

A study of more than 97,000 elderly patients with hip fracture found they were not often prescribed osteoporosis medications in an effort to prevent future fractures, and in fact, the rates declined over 12 years, a finding that surprised researchers.  

The report, published Friday in JAMA Open, discovered a steady decline in osteoporosis medication initiation rates, from 9.8% in 2004 to 3.3% in 2015. 1
Improved interventions to increase awareness of this issue and finding ways to promote collaborative care models to increase adherence to evidence-based prescribing practices are needed, the researchers said.

Researchers used data from a commercial insurance claims database from the United States. Patients were included in the study if they were 50 years and older and had not previously been treated with osteoporosis medications before their fracture. The mean (SD) age was 80.2 (10.8) years, and most—64,164 (66%)—were women.

Recurrent fractures are a major burden in public health, since 15% to 25% of patients experience a second fracture within 10 years, the authors said.

However, pharmacological treatment rates in this population are apparently decreasing, with other studies suggesting rates of any treatment use after hip fracture in the range of 13% to 21%.

The researchers used the claims database to eliminate the confounding sometimes seen in randomized control trials, and evaluated 4 instrumental variables based on factors related to healthcare access, trends, and preferences. The 4 variables were calendar year, specialist access, geographic variation in prescribing patterns, and hospital preference.

A period of 180 days after hip fracture hospitalization was used to identify a new prescription of bisphosphonates (alendronate, ibandronate, risedronate, and zolendronic acid), teriparatide, and denosumab.

An instrumental variable analysis, chosen to account for measured and unmeasured confounding, suggested that starting osteoporosis treatment in patients with a hip fracture may result in a rate of subsequent fractures that is lower by a magnitude of 4.2 events per 100 person-years (95% CI, 1.1-7.3), compared with no treatment. Instrumental variables are a way to account for unobserved differences between groups. Instrumental variables are related to treatment assignment, but not to other patient risk factors that are associated with the treatment choice or health outcome of interest. 

In the effectiveness analyses, the hospital preference instrumental variable had a stronger association with treatment (pseudo R2 = 0.20) than the other 3 instrumental variables (specialist access: pseudo R2 = 0.04; calendar year: pseudo R2 = 0.05; and geographic variation: pseudo R2 = 0.07).

Writing in an accompanying editorial, Douglas C. Bauer, MD, of the Department of Medicine, University of California, San Francisco, noted that additional analyses found that low treatment rates were even worse in men and were not explained by disproportionate underuse in older or frail patients. 2

He described the results as “a shocking failure to provide adequate care to a high-risk population.”

1. Desai RJ,  Mahesri M, Abdia Y, et al. Association of osteoporosis medication use after hip fracture with prevention of subsequent nonvertebral fractures: an instrumental variable analysis. JAMA Netw Open. 2018;1(3):e180826. doi:10.1001/jamanetworkopen.2018.0826

2. Bauer DC. Osteoporosis treatment after hip fracture: bad news and getting worse. JAMA Netw Open. 2018;1(3):e180844. doi:10.1001/jamanetworkopen.2018.0844
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