Comparative effectiveness of denosumab, teriparatide, and zoledronic acid among frail older adults: a retrospective cohort study.

The comparative effects of zoledronic acid, denosumab, and teriparatide for preventing hip fractures in frail older adults, especially those in nursing homes, were unknown. We found that denosumab and zoledronic acid may be as effective as teriparatide for hip fracture prevention in nursing home residents. INTRODUCTION: Several non-oral drugs exist for osteoporosis treatment, including zoledronic acid (ZA), denosumab, and teriparatide. Little data exist on the comparative effectiveness of these drugs for hip fracture prevention in frail older adults. We examined their comparative effectiveness in one of the frailest segments of the US population-nursing home (NH) residents. METHODS: We conducted a national retrospective cohort study of NH residents aged ≥ 65 years using 2012 to 2016 national US Minimum Data Set clinical assessment data and linked Medicare claims. New parenteral ZA, denosumab, and teriparatide use was assessed via Medicare Parts B and D; hip fracture outcomes via Part A; and 125 covariates for confounding adjustment via several datasets. We used inverse probability weighted (IPW) competing risk regression models to compare hip fracture risk between groups with teriparatide as the reference. RESULTS: The study cohort (N = 2019) included 1046 denosumab, 578 teriparatide, and 395 ZA initiators. Mean age was 85 years, 90% were female, and 68% had at least moderate functional impairment. Seventy-two residents (3.6%) had a hip fracture and 1100 (54.5%) died over a mean follow-up of 1.5 years. Compared to teriparatide use, denosumab use was associated with a 46% lower risk of hip fracture (HR 0.54, 95% CI 0.29-1.00) and no difference was observed for ZA (HR 0.70, 95% CI 0.26-1.85). CONCLUSIONS: Denosumab and ZA may be as effective as teriparatide for hip fracture prevention in frail older adults. Given their lower cost and easier administration, denosumab and ZA are likely preferable non-oral treatments for most frail, older adults.

Defining hip fracture with claims data: outpatient and provider claims matter.

Medicare claims are commonly used to identify hip fractures, but there is no universally accepted definition. We found that a definition using inpatient claims identified fewer fractures than a definition including outpatient and provider claims. Few additional fractures were identified by including inconsistent diagnostic and procedural codes at contiguous sites. INTRODUCTION: Medicare claims data is commonly used in research studies to identify hip fractures, but there is no universally accepted definition of fracture. Our purpose was to describe potential misclassification when hip fractures are defined using Medicare Part A (inpatient) claims without considering Part B (outpatient and provider) claims and when inconsistent diagnostic and procedural codes occur at contiguous fracture sites (e.g., femoral shaft or pelvic). METHODS: Participants included all long-stay nursing home residents enrolled in Medicare Parts A and B fee-for-service between 1/1/2008 and 12/31/2009 with follow-up through 12/31/2011. We compared the number of hip fractures identified using only Part A claims to (1) Part A plus Part B claims and (2) Part A and Part B claims plus discordant codes at contiguous fracture sites. RESULTS: Among 1,257,279 long-stay residents, 40,932 (3.2%) met the definition of hip fracture using Part A claims, and 41,687 residents (3.3%) met the definition using Part B claims. 4566 hip fractures identified using Part B claims would not have been captured using Part A claims. An additional 227 hip fractures were identified after considering contiguous fracture sites. CONCLUSIONS: When ascertaining hip fractures, a definition using outpatient and provider claims identified 11% more fractures than a definition with only inpatient claims. Future studies should publish their definition of fracture and specify if diagnostic codes from contiguous fracture sites were used.