Fragility fracture identifies patients at imminent risk for subsequent fracture: real-world retrospective database study in Ontario, Canada

Abstract

Background: The secondary fracture prevention gap in the osteoporosis field has been previously described as a 'crisis'. Closing this gap is increasingly important in the context of accumulating evidence showing that an incident fragility fracture is associated with an increased risk of subsequent fracture within 1-2 years, known as imminent fracture risk. The objective of this study was to use health services data to characterize the time between index fragility fractures occurring at different osteoporotic sites and subsequent fractures.

Methods: This retrospective observational study used de-identified health services data from the publicly funded healthcare system in Ontario, the largest province of Canada. Patients aged > 65 with an index fragility fracture occurring between 2011 and 2015 were identified from the ICES Data Repository using International Classification of Diseases (ICD)-10 codes. We examined median time to subsequent fragility fractures for osteoporotic fracture sites until the end of follow-up (2017). BMD assessment and use of osteoporosis therapies following index fracture were also characterized.

Results: Among 115,776 patients with an index fragility fracture, 17.8% incurred a second fragility fracture. Median time between index and second fracture occurring at any site was 555 days (interquartile range: 236-955). For each index fracture site examined, median time from index to second fracture was < 2 years. The proportion of patients with BMD assessment was 10.3% ≤1 year prior to and 16.4% ≤1 year post index fracture. The proportion of patients receiving osteoporosis therapy was 29.8% ≤1 year prior, 34.6% ≤1 year post, and 25.9% > 3 years post index fracture.

Conclusions: This cohort of Canadian patients aged > 65 years who experienced a fragility fracture at any site are at imminent risk of experiencing subsequent fracture within the next 2 years and should be proactively assessed and treated.

Keywords: Fragility fracture; Imminent fracture risk; Osteoporosis; Post fracture care; Real-world data; Secondary fracture prevention; Subsequent fracture.

Fig. 1

Median time to second fragility fracture occurring at any site (by index fracture site). Number of index fractures, number and proportion of second fragility fractures at any site, and time to second fracture stratified by site of index fracture. Fracture sites are in descending order of number of index fractures. Abbreviations: IQR, interquartile range

Fig. 2

Proportion of fragility fracture patients undergoing BMD assessment ≤1 year prior to and ≤ 1 year post index fracture by: a sex; b age group; and c site of index fracture

Fig. 3

Proportion of patients, by sex and age group, receiving any osteoporosis treatment within 1 year prior* to and during the time of index fragility fracture and at any time post index fracture. * ≤ 1 year prior period included osteoporosis treatments dispensed within 1 year prior to and during the time of index fracture, and also captured the period of 7 days post index fracture hospital discharge date (to reflect a potential delay in the dispensing of osteoporosis treatments prescribed at the time of the index event). Post index event dispensed osteoporosis treatments were assessed from 8 days post index fracture hospital discharge date until the end of study follow-up. Osteoporosis treatments examined in this cohort included bisphosphonates (alendronate, etidronate, risedronate, or zoledronic acid), denosumab, teriparatide, raloxifene, and HRT