Fig. 1.

Structure of the Markov model. In this model, the strategy of OPRM1 screening was compared to no screening. In the screening strategy (1; in dark gray), alcohol-dependent patients with a G-allele received naltrexone, and AA homozygotes randomly received either acamprosate or naltrexone. In the no screening strategy (2; in white), treatment allocation was non-genotype guided, and therefore patients randomly received acamprosate or naltrexone. The risk of relapse and associated costs and effects were compared across strategies.