Excessive Alcohol Use Table 1. Impact of the SBI. Estimates and their 95% confidence interval (between brackets). Total Dutch population aged 20–65 years Number of excessive and dangerous drinkers in total Dutch population aged 20–65 years Number of persons screened in the opportunistic screening programme in the GP practice Number of excessive and dangerous drinkers found during the screening programme Number of excessive and dangerous drinkers receiving the brief intervention Number of drinkers who became moderate drinkers or abstained from alcohol *Derived from the annual General Public Health and Lifestyle Survey (Dutch initials: POLS) conducted by Statistics Netherlands. doi:10.1371/journal.pone.0005696.t001 N 10,029,000* 1,386,000* 6,176,000 (5,740,000–6,545,000) 853,000 (793,000–904,000) 577,000 (389,000–734,000) 39,000 (2,000–92,000) (ICER), expressed in euros per QALY (Quality Adjusted Life Years) [14]. We performed our assessment using a dynamic model for the entire Dutch population (the RIVM Chronic Disease Model (CDM)), taking a healthcare perspective focusing on health benefits and health care costs. The health care costs included are the costs of opportunistic screening, costs of brief intervention, the costs of alcohol related diseases and costs of diseases unrelated to alcohol in life years gained. There are previous studies which investigated the cost-effectiveness of interventions similar to SBI [15,16,17,18,19] e.g. Fleming et al. 2000 [19] calculated from the societal perspective that the benefit-cost ratio of the brief intervention was 5.6:1, or $56,263 in total benefit for every $10,000 invested. Only one of the previous studies [15] investigated the cost-effectiveness of SBI in costs per QALY gained. However, this study did not take into account the medical costs of diseases unrelated to alcohol in life years gained and did not account for the fact that quality of life decreases at older ages. Results The total Dutch population aged 20–65 years accounts for about 10 million people. On average 6,176,000 of them are screened during the opportunistic screening programme. As table 1 shows, 1,386,000 excessive and dangerous drinkers exist in the Dutch population aged 20–65. On average 853,000 of them are found with the screening instrument, and 577,000 of them receive the brief intervention. This results in 39,000 people becoming moderate drinkers or abstain from alcohol, which is about 3% of the amount of excessive drinkers in the Dutch population aged 20–65. In the SBI scenario the reduction in alcohol consumption results in a decrease in the incidence of alcohol related diseases, and in a decrease in health care costs of these diseases. As a consequence, this causes a gain in life years and QALYs compared to current practice scenario (no provision of SBI). Figure 1 displays a costs (differences in intervention+lifetime health care costs) and effects (QALYs gained) plane for SBI scenario compared to current practice scenario, for different values of the model input parameters. This figure displays the results of a PSA. Each point represents incremental costs and effects of one run of the CDM, taking as input a random sample drawn from the distributions of the model parameters. The spread of the cloud of points in the figure shows the uncertainty in the estimation of the joint distribution of costs and effects. As can be seen from this figure, health care costs increase as the amount of QALYs gained increases. If the numbers of person receiving SBI increases, both costs of SBI will increase, and the amount of QALYs gained. Incremental life years gained, QALYs gained, health care costs incurred and the resulting ICER for the SBI scenario are shown in Table 2. Figure 1. Incremental costs and effects of SBI compared to current practice scenario for the target population. doi:10.1371/journal.pone.0005696.g001 PLoS ONE | www.plosone.org 2 May 2009 | Volume 4 | Issue 5 | e5696