Compliance and persistence with bisphosphonate dosing regimens among women with postmenopausal osteoporosis.

OBJECTIVE: Poor compliance and persistence with bisphosphonates is a concern in postmenopausal osteoporosis due to its negative impact on fracture risk and healthcare costs as well as quality of life. Reducing oral bisphosphonate dosing frequency is one measure available to increase therapy convenience and practicality, with the hope of improving compliance and persistence. This study compared compliance and persistence with weekly and daily bisphosphonate regimens for postmenopausal osteoporosis.

METHODS: Administrative claims data (1997-2002) from 30 health plans were used to identify postmenopausal women (> 45 years) with osteoporosis, who had been newly prescribed a once-weekly (QW alendronate 35 mg or 70 mg) or once-daily (QD alendronate 5 mg or 10 mg or risedronate 5 mg) bisphosphonate. QW and QD cohorts were followed for 12 months from initial prescription. Medication possession ratios (MPRs) measured refill compliance during follow-up. Persistence was calculated as the number of days from the initial prescription to a lapse of > 30 days after completion of the previous refill.

RESULTS: Data were available for 2741 women (QW, N = 731, QD, N = 2010). QW users had significantly higher medication compliance than QD users (69.2% vs. 57.6% MPR, p < or = 0.0001). QW users persisted with therapy significantly longer than QD users (p < 0.0001) and had higher rates of retention on treatment at 12 months than QD users (44.2% QW; 31.7% QD). Dosing frequency was the strongest predictor of time to discontinuation (p < 0.0001).

CONCLUSIONS: Postmenopausal women prescribed a weekly bisphosphonate had significantly better compliance and persistence than those taking more frequent, daily bisphosphonate doses. However, compliance and persistence rates for both regimens were suboptimal, suggesting that less frequent dosing intervals may provide an opportunity to further improve the consistent use of bisphosphonate therapy.