Establishing baseline absolute risk of subsequent fracture among adults presenting to hospital with a minimal-trauma-fracture

Background One in three women and one in five men are expected to experience a minimal-trauma-fracture after the age of 50-years, which increases the risk of subsequent fracture. Importantly, timely diagnosis and optimal treatment in the form of a fracture liaison service (FLS), has been shown to reduce this risk of a subsequent fracture. However, baseline risk of subsequent fracture among this group of FLS patients has not been well described. Therefore, this study aims to estimate absolute risk of subsequent fracture, among women and men aged 50-years or more, presenting to hospital with a minimal-trauma-fracture. Methods Women and men aged 50-years or more with a minimal-trauma-fracture, presenting to hospitals across the South Western Sydney Local Health District between January 2003 and December 2017 were followed to identify subsequent fracture presentations to hospital. Absolute risk of subsequent fracture was estimated, by taking into account the competing risk of death. Results Between January 2003 and December 2017-15,088 patients presented to the emergency departments of the five hospitals in the SWSLHD (11,149, women [74%]), with minimal-trauma-fractures. Subsequent fractures identified during the follow-up period (median = 4.5 years [IQR, 1.6-8.2]), occurred in 2024 (13%) patients. Death during the initial hospital stay, or during a subsequent hospital visit was recorded among 1646 patients (11%). Women were observed to have 7.1% risk of subsequent fracture after 1-year, following an initial fracture; and, the risk of subsequent fracture after 1-year was 6.2% for men. After 5-years the rate among women was 13.7, and 11.3% for men, respectively. Cumulative risk of subsequent fracture when initial fractures were classified as being at proximal or distal sites are also presented. Conclusion This study has estimated the baseline risk of subsequent fracture among women and men presenting to hospital with minimal trauma fractures. Importantly, this information can be used to communicate risk to patients deciding to attend an osteoporosis refracture prevention clinic, and highlight the need for screening, and initial of treatment when indicated, once a minimal-trauma-fracture has occurred.