Validated prediction of imminent risk of fracture for older adults

Abstract

Objectives: To develop and validate predictive models for imminent fracture risk in a Medicare population.

Study design: This retrospective administrative claims (Humana Research Database) study assessed imminent risk in Humana's Medicare Advantage and Prescription Drug plan members.

Methods: Individuals (aged 67-87 years on January 1, 2015 [index]) with 1 year or more of history were followed for 3 months to up to 2 years, with censoring at death/disenrollment. The cohort was split into training and validation samples (1:1). Cox regression models assessed demographics, fracture history, medically significant falls, osteoporosis-related factors, frailty markers, and selected medications and comorbidities for independent predictors (P <.001) of incident nontraumatic clinical fractures in 12 and 24 months. A 6-variable model of 12-month risk used a published method for the risk-scoring point system.

Results: Of 1,287,354 individuals (mean age, 74.3 years; 56% female; 84% white), 3.8% had at least 1 fragility fracture at 12-month follow-up; 6.6% experienced fracture at 24 months (women vs men: 12 months, 4.8% vs 2.5%; 24 months, 8.3% vs 4.4%; both P <.01). At 12 months, recent fracture conferred approximately 3-fold-higher fracture risk (vs no recent fracture). Older age, white race, female sex, osteoporosis-related screening/diagnosis/medication, antidepressant/antipsychotic/sedative hypnotic/muscle relaxant medications, history of falls, fracture history, and respiratory conditions also increased risk (all P <.0001). The simplified model (recent fracture, age, sex, race, falls, antidepressant/antipsychotic/sedative hypnotic/muscle relaxant medications) performed well (C statistic = 0.71).

Conclusions: Recent fracture, older age, female sex, white race, falls, and antidepressant/antipsychotic/sedative hypnotic/muscle relaxant medications predict imminent fracture risk in an older-adult Medicare Advantage population. Imminent fracture risk can be assessed using 6 easily quantified factors.