Introduction: Clinical fractures are associated with an increased relative risk of future fractures, but the absolute risk and timing of new clinical fractures immediately after a clinical fracture have not been reported extensively. The study objective was to determine the absolute risk of subsequent clinical fractures within 2 years after a clinical fracture.
Methods: We analyzed clinical fracture data from a university hospital recruiting all fractures in the area between January 1999 and December 2001. Subjects were 2,419 male and female patients aged 50 years and older, with a total of 2,575 fractures. There were 139 patients with more than one simultaneous fracture. Mean age was 66 years for males and 72 for females.
Results: The cumulative incidence of patients with new clinical fractures over 2 years was 10.8% (262/2,419). In the 262 patients with subsequent fractures, we observed a higher mean age, more females and more often multiple baseline fractures compared with the 2,157 patients without subsequent fractures. Kaplan-Meier analysis indicated that age, gender and having multiple baseline fractures contributed significantly to cumulative new fracture incidence. Cox regression showed that these variables independently contributed to a higher subsequent fracture incidence. New fracture incidence was higher with increasing age ( p <0.001; hazard ratio [HR] 1.2 per decade; confidence interval [CI] 1.1-1.3). Females had a new fracture incidence of 12.2% compared with 7.4% in males ( p =0.015; HR 1.5; CI 1.1-2.0). Patients with multiple baseline fractures had a new fracture incidence of 17.3% compared with 10.4% for subjects with one baseline fracture ( p =0.006; HR 1.8; CI 1.2-2.7). Of all clinical fractures occurring within 2 years after a clinical fracture, 60% occurred during the first year and 40% during the second year ( p =0.005). The absolute risk to develop an incident clinical fracture within 2 years after any clinical fracture was 10.8%. Increased age, female gender and the presence of multiple simultaneous fractures at baseline each independently increased the risk of incident fracture. Significantly more fractures occurred in the first year following the index fracture than in the second year.
Conclusion: Altogether, these data support the need for early prevention of future fracture among individuals with a fracture after age 50, using interventions which have been shown to have a rapid anti-fracture benefit.