The study used a Markov state-transition model to estimate the clinical and economic outcomes, with the two bisphosphonates, using effectiveness data from one clinical study. The time horizon in the base-case was four years and the authors stated that the study was performed from the German Social Insurance system perspective.
The effectiveness evidence came from a medical claims database study, the Risedronate and Alendronate (REAL) study, which provided comparative data on patients taking risedronate versus alendronate. The main clinical parameters were the relative risk of hip fracture and the associated mortality.
Monetary benefit and utility valuations:
The utility estimates were based on age-specific European Quality of life (EQ-5D) questionnaire responses, from a Swedish study, using multipliers from published literature to reflect the impact of hip fractures.
Measure of benefit:
The measure of benefit was the number of quality-adjusted life-years (QALYs), which were discounted at an annual rate of 3%.
The direct costs included those of drugs, which were from a pharmaceutical company's website, and of hip fractures, which were from a published German study. They were based on 1995 to 1996 prices, which were updated to the 2008 price-year, using the medical care component of the Consumer Price Index for Germany. The currency was Euros (EUR).
Analysis of uncertainty:
A probabilistic sensitivity analysis was performed on the relative risk reductions, associated with each of the treatments. One-way and two-way deterministic sensitivity analyses were performed on a range of model parameters.