A Markov model was used to fully capture the progressive nature of osteoporosis and a full description of the model was provided. The time horizon was 30 years (or until the patient's death) and the authors reported that a societal perspective was adopted.
: The clinical inputs to the model were derived from extensive literature searches and some assumptions were made for adverse events, mortality, and morbidity. All assumptions were clearly reported. The key clinical parameters were the prevalence of osteoporosis, the positive predictive value of the OST, and the relative risk reduction in vertebral and non-vertebral fractures, with alendronate therapy versus without.
Monetary benefit and utility valuations:
The utility values were from published studies that used standardised methods (time trade-off or standard gamble technique) to measure the preferences.
Measure of benefit:
Life-years gained (LYG) and quality-adjusted life-years (QALYs) were the measures of benefit and these were discounted at an annual rate of 3%.
The analysis included the direct costs for the first year from fracture of the hip, wrist, or vertebra; home health care and nursing home care due to fracture; bone densitometry screening; annual treatment with alendronate; and oesophageal ulcer treatment. These costs were derived from published studies or from Medicare data. All costs were adjusted for inflation, using the urban medical care component of the consumer price index, and reported for the price year 2006 in US dollars ($). An annual discount rate of 3% was applied.
Analysis of uncertainty:
One-way sensitivity analysis was conducted on all the input parameters.