School of Biomedical Engineering, University of Technology Sydney, Sydney, Australia; Garvan Institute of Medical Research, Sydney, Australia; Faculty of Medicine, UNSW Sydney, New South Wales, Australia
Thao Ho-Le
School of Biomedical Engineering, University of Technology Sydney, Sydney, Australia
Dana Bliuc
Garvan Institute of Medical Research, Sydney, Australia; Faculty of Medicine, UNSW Sydney, New South Wales, Australia
Bo Abrahamsen
Department of Medicine, Holbæk Hospital, Holbæk, Denmark; Department of Clinical Research, Odense Patient Data Explorative Network, University of Southern Denmark, Odense, Denmark; Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences University of Oxford, Oxford, United Kingdom
Kontraktenheden, North Denmark Region, Denmark, Denmark
Peter Vestergaard
Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark; Steno Diabetes Center North Jutland, Aalborg, Denmark
Garvan Institute of Medical Research, Sydney, Australia; Faculty of Medicine, UNSW Sydney, New South Wales, Australia; School of Medicine Sydney, University of Notre Dame Australia, Sydney, Australia
School of Biomedical Engineering, University of Technology Sydney, Sydney, Australia; School of Medicine Sydney, University of Notre Dame Australia, Sydney, Australia; School of Population Health, UNSW Medicine, UNSW Sydney, Kensington, Australia
Background: Fragility fracture is associated with an increased risk of mortality, but mortality is not part of doctor-patient communication. Here, we introduce a new concept called ‘Skeletal Age’ as the age of an individual’s skeleton resulting from a fragility fracture to convey the combined risk of fracture and fracture-associated mortality for an individual. Methods: We used the Danish National Hospital Discharge Register which includes the whole-country data of 1,667,339 adults in Denmark born on or before January 1, 1950, who were followed up to December 31, 2016 for incident low-trauma fracture and mortality. Skeletal age is defined as the sum of chronological age and the number of years of life lost (YLL) associated with a fracture. Cox’s proportional hazards model was employed to determine the hazard of mortality associated with a specific fracture for a given risk profile, and the hazard was then transformed into YLL using the Gompertz law of mortality. Results: During the median follow-up period of 16 years, there had been 307,870 fractures and 122,744 post-fracture deaths. A fracture was associated with between 1 and 7 years of life lost, with the loss being greater in men than women. Hip fractures incurred the greatest loss of life years. For instance, a 60-year-old individual with a hip fracture is estimated to have a skeletal age of 66 for men and 65 for women. Skeletal Age was estimated for each age and fracture site stratified by gender. Conclusions: We propose ‘Skeletal Age’ as a new metric to assess the impact of a fragility fracture on an individual’s life expectancy. This approach will enhance doctor-patient risk communication about the risks associated with osteoporosis. Funding: National Health and Medical Research Council in Australia and Amgen Competitive Grant Program 2019.
