Decision tree model of the human and economic consequences of artemisinin-combination therapy malaria treatment failure. The decision tree diagram illustrates how malaria incidence, deaths and costs are calculated in each of the two scenarios. The top branch represents the scenarios in which artemisinins are effective. This structure is replicated in the bottom branch representing the scenario of artemisinin resistance, with the necessary adjustments to parameter values. The branch following the blue node at High transmission is also replicated with parameter adjustments at the Low transmission node.