Analytical approach:
The analysis was based on a decision tree. A short-term horizon that covered the hospitalisation period until discharge was used for the cost-effectiveness analysis, and a 30-year time horizon that covered the survival of the offspring was used for the cost-utility analysis. The authors stated that the analysis took the perspective of the payer.
Effectiveness data:
Most of the epidemiological inputs were from a large pregnancy database, containing records of 14,500 births over four years, of the major health maintenance organisations in Israel. Other data were from the Central Bureau of Statistics. The treatment effect for preventive measures was from several published studies, including a meta-analysis. The accuracy of screening was a key input for the model and was from published studies.
Monetary benefit and utility valuations:
The utility values were from published studies.
Measure of benefit:
Quality-adjusted life-years (QALYs) were used for the cost-utility analysis, and pre-eclampsia cases avoided were used for the cost-effectiveness analysis. A 3% annual discount rate was applied for the long-term cost-utility analysis.
Cost data:
The economic analysis included the costs of the screening tests, standard care (visits and preventive measures), hospitalisation before delivery, vaginal delivery, caesarean delivery, and neonatal intensive care unit stay. The costs were based on official list prices provided by the Israeli Ministry of Health. The costs of the screening tests were based on prices in Israel, as well as in other European countries. All costs were converted to US $, using purchasing power parity. A 3% annual discount rate was applied to the long-term costs.
Analysis of uncertainty:
One-way sensitivity analyses were carried out on selected inputs, including the cost of the screening test, the false-positive rate, pre-eclampsia prevalence, the detection rate of the test, and the effectiveness of preventive measures. Some alternative estimates or ranges were from published sources.