Oral Presentation 33rd ASM of the Australian & New Zealand Bone & Mineral Society 2023

“Skeletal Age” for mapping the impact of fracture on mortality using clinical data (#51)

Thach Tran 1 2 , Dinh Tan Nguyen 2 , Lisa Langsetmo 3 , Nancy E Lane 4 , Tuan V Nguyen 2
  1. Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
  2. School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, Australia
  3. School of Public Health, University of Minnesota, Twin cities, Minneapolis, United States
  4. Department of Medicine, University of California at Davis, School of Medicine, Sacramento, CA, United States

We used registry-based data to propose a new metric called “Skeletal Age” (SA) for conveying the combined risk of fracture and fracture-related mortality in patient-doctor risk communication1. This study sought to estimate SA for specific fracture sites using clinically measured data.

Skeletal Age is conceptually defined as the age of an individual's skeleton resulting from a fragility fracture. Thus, for an individual with a fracture associated with increased mortality risk, the SA would be expected to be higher than the individual's chronological age. SA is estimated as the sum of chronological age and the number of years of life loss associated with each fracture site for an individual with a given clinical risk profile, including age, BMD, BMI, lifestyle factors, and comorbidities.

The study involved 5994 community-dwelling elderly men in the Osteoporotic Fractures in Men Study with an average age of 73.6 (±5.9) years. During a median follow-up of 13.9 years (IQR: 8.5, 17.5), 1085 men sustained a fragility fracture followed by 694 deaths. Hip, other proximal, and lower leg fractures were associated with a significantly increased risk of death. On average, a fragility fracture was associated with 1 to 9 years of life lost, with the loss being greater in younger patients with a hip, femur, or pelvis fracture (Figure). A 60-year man with a hip fracture is estimated to have a SA of 68.1 (95% CI: 66.9, 69.2); whereas the estimated SA for a 70-year man with a hip fracture is 76.3 (75.4, 77.1). 

Our results reemphasize that most fractures are associated with increased mortality risk and hence reduced life expectancy. The findings were consistent in both registry-based and clinical data. The proposed Skeletal Age supplements the traditional relative risk as a metric for conveying the mortality consequence of fracture, making the patient risk communication more intuitive.

64b9bead2ce76-SA+for+fractures.jpg doctor-

  1. 1. Tran T, Ho-Le T, Bliuc D, et al. 'Skeletal Age' for mapping the impact of fracture on mortality. Elife 2023;12:e83888