Association between teriparatide adherence and healthcare utilization and costs among hip fracture patients in the United States.

ABSTRACT

PURPOSE: This study examined the association between teriparatide (TPTD) adherence, and healthcare utilization and costs among hip fracture (HFx) patients. METHODS: Individuals aged 50years and older with an HFx between 1/1/2002-12/31/2010 were identified from a large US administrative claims database. The first HFx date during this period was designated as the index. Selected patients had at least 6months of pre-index continuous enrollment (baseline) and no baseline TPTD use, cancer, or Paget's disease. Patients initiating TPTD post-index were followed until censoring at switch to bisphosphonates, disenrollment, 36months post-index, or diagnosis of cancer or Paget's disease. Teriparatide adherence was measured as the proportion of days covered (PDC) by TPTD prescriptions, during the follow-up period, to construct three adherence groups low (PDC≤0.5), medium (0.50.8) adherence. Outcome measures were repeated HFx, number of inpatient admissions, and per-patient-per-month (PPPM) healthcare costs. Multivariable generalized linear models examined the association between the TPTD adherence groups and the outcomes, adjusting for cross-group differences in patient characteristics.

RESULTS:

A total of 824 patients (mean age 75years, 90% female) were included 30% low, 27% medium, and 44% high adherence. In multivariable analyses, high adherence was significantly (all p<0.05) directly associated with increased PPPM pharmacy costs ($621 low, $1093 medium, and $1572 high), but also with the lowest inpatient ($963 low, $960 medium, and $629 high) and outpatient ($1087 low, $1068 medium, and $776 high) costs, leading to the highest total costs in the medium adherence group but similar costs in the high and low adherence groups ($2599 low, $3163 medium, and $2869 high). The high adherence group also had the lowest number of inpatient admissions.

CONCLUSIONS:

Significantly increased pharmacy costs associated with the high TPTD adherence group were offset by significantly fewer inpatient admissions, fewer repeated HFx, and lower inpatient and outpatient costs.