Analytical approach:
An economic evaluation based on a multicentre randomised trial. The time horizon was one year. The authors stated that the analysis was conducted from two perspectives: health and social care, and societal.
Effectiveness data:
Effectiveness data were derived from a multicentre randomised trial conducted across Amsterdam, London, Leipzig and Verona; 409 patients were recruited across the four centres and were followed up from baseline for at least a year. The primary outcomes of the trial were the mental component summary score (MCS) of the Medical Outcome Study SF-36 (36-item Short Form Health Survey) and quality-adjusted life-years (QALYs).
Monetary benefit and utility valuations:
Utility gain over one year was measured using SF-36. The EQ-5D measure was considered in a sensitivity analysis. SF-6D and EQ-5D questionnaires were administered by face-to-face interviews taken at baseline (prior to randomisation) and at one year follow-up by assessors blinded to participants' group allocation. Adjustments were made for baseline differences. Utility weights were applied to health state values using general population valuations to generate QALYs.
Measure of benefit:
The health benefit was QALYs measured using the SF-6D.
Cost data:
Data on use of health, social care and criminal justice systems, time off work and informal care use were collected using a tailored version of the client Socio-demographic and Service Receipt Inventory (CSSRI-EU) administered by face-to-face interview with participants at baseline and one year follow-up. Resource use related to session durations and therapist preparation time was extracted from therapist patient case notes. Country-specific unit costs were applied to resource use data. Most unit costs were obtained from local or national data for each country. All medication costs were derived using UK prices. Costs were converted to Euros (€) using gross domestic product (GDP) purchasing power parity conversion rates and inflated to 2011 prices using country-specific GDP inflation rates.
Analysis of uncertainty:
Cost-effectiveness acceptability curves (CEAC) were constructed using the bootstrap technique. The CEAC showed the probability that the intervention was cost-effective over a range of willingness-to-pay (for an additional QALY) thresholds. 95% confidence intervals (CI) were reported alongside mean difference values and standard deviations (SD) were reported alongside mean values.