Prevalence and cost of subsequent fractures among U.S. patients with an incident fracture

Abstract

BACKGROUND: The prevalence and cost of subsequent fractures among patients with an incident fracture are not well defined. OBJECTIVE: To assess the prevalence of, and costs associated with, subsequent fractures in the year after an incident fracture. METHODS: This was a retrospective claims database analysis using data from Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (index fracture), were continuously enrolled in the health plan for = 1 year before and after the index fracture, and were aged = 65 years in the Medicare group or = 50 years in the commercial group at the time of the index fracture. Subsequent fractures were identified by ICD-9-CM codes and were defined as the second fracture occurring = 3 to = 12 months after the index fracture (= 6 to =12 months for fractures at the same site as the index fracture). Rates of subsequent fractures were calculated as the number of patients who had a subsequent fracture divided by the total sample size. After propensity matching of demographic and clinical variables, we determined the total medical and pharmacy costs accrued within 1 year of the index fracture by patients with and without a subsequent fracture. Health care costs were compared between patients with and without a subsequent fracture using McNemar's test. RESULTS: A total of 45,603 patients were included in the Medicare group, and 54,145 patients were included in the commercial group. In the Medicare group, 7,604 (16.7[%]) patients experienced a subsequent fracture. The proportion of patients with a subsequent fracture was highest among patients with multiple index fractures (26.2[%], n = 905), followed by those with hip (25.5[%], n = 1,280) and vertebral (20.2[%], n = 1,908) index fractures. In the commercial group, 6,256 (11.6[%]) patients experienced a subsequent fracture. The proportion of patients with a subsequent fracture paralleled those observed in the Medicare group: 24.5[%] (n = 808) in patients with multiple index fractures, 22.0[%] (n = 525) in those with hip fracture, and 14.5[%] (n = 841) in those with vertebral fracture. For vertebral, hip, and nonhip nonvertebral fractures, subsequent fractures were most frequently of the same type as the index fracture. The mean total health care cost (sum of medical and pharmacy costs) in the year following the incident fracture for the Medicare group was $27,844 and differed significantly between patients with and without a subsequent fracture ($34,897 vs. $20,790; P < 0.001). The mean total health care cost in the year following the incident fracture for the commercial group was $29,316 and also differed significantly between patients with and without a subsequent fracture ($39,501 vs. $19,131; P < 0.001). CONCLUSIONS: Among patients with an incident fracture, those who experienced a subsequent fracture in the following year had significantly higher health care costs than those who did not. A subsequent fracture is most likely to be of the same type as the initial fracture.