A model of the public health impact of improved treatment persistence in post-menopausal osteoporosis in France

Background: Treatment of osteoporosis with bisphosphonates can lead to important reductions in fracture rates. The effectiveness of bisphosphonates is however limited by inadequate treatment persistence. The introduction of weekly administered forms has been associated with improved treatment persistence. Objectives: This modelling study was designed to estimate the gain in persistence associated with a monthly treatment and the subsequent impact on fracture rates. Methods: Osteoporosis treatment rates and persistence rates were obtained from a French general practice registry for weekly and daily bisphosphonates and from a US managed care database for monthly bisphosphonates. Survival analyses were used to assess persistence. Fracture, hospitalisation and fracture rates were attributed based on data from clinical trials with bisphosphonates and epidemiological data. Results: Using a monthly treatment regimen, the reduction in the risk of vertebral and non-vertebral fractures with respect to untreated subjects was estimated to be 21.2% and 9.5% respectively. The reduction in risk of hospitalisation was estimated at 17.0% and the reduction of mortality at 18.1%. These reductions are around 60% higher as those estimated for daily bisphosphonate treatment and 25% higher than for weekly bisphosphonate treatment. Conclusion: This modelling approach supports the notion that increased treatment persistence associated with use of monthly bisphosphonate treatment regimens may result in a significant impact on osteoporotic fracture rates and consequent hospitalisation and mortality rates. (C) 2007 Elsevier Masson SAS. All rights reserved.