Analytical approach:
A pharmacoeconomic discrete event simulation with a five-year time horizon was used. This was based on a published model (Heeg, et al. 2005, see ‘Other Publications of Related Interest’ below for bibliographic details) that was slightly modified for the Swedish setting. The authors reported that the third-party payer perspective was taken.
Effectiveness data:
The effectiveness data were mainly from the literature or were estimated by an expert panel. The main outcome measures were the disease severity, measured by the Positive and Negative Syndrome Scale (PANSS), and patient compliance. The two treatments were assumed to be identical, in all aspects, except compliance.
Monetary benefit and utility valuations:
Using a specific relationship (negative correlation), identified from the literature (Lenert, et al. 2004, see 'Other Publications of Related Interest' below for bibliographic details), the PANSS scores were translated into utility scores. The PANSS scores for patients who relapsed were from a randomised controlled trial, while those for patients who were in remission were from another study.
Measure of benefit:
Quality-adjusted life-years (QALYs) were the measure of benefit and they were discounted at an annual rate of 3%.
Cost data:
The analysis included the costs of community care, a staffed hostel, hospitalisation, and psychiatric visits. The probability of hospitalisation based on patient characteristics was reported, but the resource use data were not. The costs were from official national sources (the Regional Price List) and were reported as total categories, with unit costs provided only for psychiatric visits. All costs were reported in Swedish kronor (SEK) for the price year 2007. They were adjusted for inflation, using the Consumer Price Index, and were discounted at an annual rate of 3%.
Analysis of uncertainty:
Sensitivity analysis was conducted, using a scenario where all partially compliant patients were assumed to be either fully compliant or fully non-compliant.