Osteoporosis medication use after hip fracture in U.S. patients between 2002 and 2011

Abstract

Hip fractures are common, morbid, costly, and associated with subsequent fractures. Historically, postfracture osteoporosis medication use rates have been poor, but have not been recently examined in a large-scale study. We conducted a retrospective, observational cohort study based on U.S. administrative insurance claims data for beneficiaries with commercial or Medicare supplemental health insurance. Eligible participants were hospitalized for hip fracture between January 1, 2002, and December 31, 2011, and aged 50 years or older at admission. The outcome of interest was osteoporosis medication use within 12 months after discharge. Patients were censored after 12 months, loss to follow-up, or a medical claim for cancer or Paget's disease, whichever event occurred first. During the study period, 96,887 beneficiaries met the inclusion criteria; they had a mean age of 80 years and 70% were female. A total of 34,389 (35.5%) patients were censored before reaching 12 months of follow-up. The Kaplan-Meier estimated probability of osteoporosis medication use within 12 months after discharge was 28.5%. The rates declined significantly from 40.2% in 2002, to 20.5% in 2011 (p for trend <0.001). In multivariable Cox proportional hazards models, a number of patient characteristics were associated with reduced likelihood of osteoporosis medication use, including older age and male gender. However, the predictor most strongly and most positively associated with osteoporosis medication use after fracture was osteoporosis medication use before the fracture (hazard ratio = 7.45; 95% confidence interval [CI], 7.23-7.69). Most patients suffering a hip fracture do not use osteoporosis medication in the subsequent year and treatment rates have worsened.

Keywords: HIP FRACTURE; OSTEOPOROSIS; TREATMENT PATTERNS.

Fig 1

Distribution of time to osteoporosis medication use within 36 months after discharge (Kaplan-Meier method). Six months, all patients = 0.162; patients with 3+ months of enrollment (ie, excluding patients censored before 3 months) = 0.169. Six months: all patients = 0.236; patients with 6+ months of enrollment = 0.254. Nine months: all patients = 0.264; patients with 9+ months of enrollment = 0.290.

Fig 2

Annual unadjusted probability of osteoporosis medication use within 12 months after discharge (Kaplan-Meier method).

Fig 3

Unadjusted probability of osteoporosis medication use within 12 months after discharge, by U.S. Census Bureau Division.