Persistence and compliance of medications used in the treatment of osteoporosis--analysis using a large scale, representative, longitudinal German database.

OBJECTIVE: Osteoporosis can be effectively treated with a number of medications. However, high persistence and compliance are required to assure efficacy. This study analyses persistence and compliance with a variety of medical interventions including p.o., i.v. and s.c. administrations in Germany.
METHODS: This retrospective cohort study used a representative longitudinal database (IMS® LRx) comprising longitudinal prescription data for Germany from almost 80% of all German prescriptions of members of the German statutory health insurance system. Persistence is defined as the proportion of patients who remained on their initially prescribed therapy at 1 year. Compliance is measured indirectly based on the medication possession ratio (MPR).
RESULTS: A total of more than 1 million patients (1,107,482) for the period 07/2007 - 06/2009 was identified in the database who received a prescription for a bisphosphonate, strontium or PTH. Of these, 268,568 patients fulfilled further inclusion criteria and were included in the persistence and compliance analysis. At 12 months the proportion of patients that remained on treatment were 65.6% for zoledronate 5 mg; 56.6% for ibandronate i.v. 3 mg; 54.7% for PTH (teriparatide and 1-84 PTH), 51.0% for ibandronate 150 mg p.o.; 44.8% for alendronate 70 mg; 43.4% for etidronate. Other values were risedronate plus calcium 42.3%; alendronate plus vitamin D 37.8%; risedronate 35 mg 35.2%; risedronate 5 mg 30.6%; strontium ranelate 31.4% and alendronate 10 mg 17.3%.
CONCLUSION: Persistence and compliance during the treatment of osteoporosis were found to be insufficient. Treatment using the intravenous route and PTH showed the highest persistence and compliance rates and daily oral bisphosphonates the lowest. More effort to improve treatment compliance and persistence is needed to assure clinical efficacy.