“…In this study, for cost-effectiveness analysis, after drawing the decision tree model in the TreeAge pro 2011 software, the ICER was calculated and the WHO approach was used to calculate the cost-effectiveness threshold so that if the incremental cost-effectiveness ratio is less than three times the GDP per capita, the strategy is costeffective (20,21). An ICER is calculated by dividing the difference in total costs (incremental cost) by the difference in the chosen measure of health outcome (incremental effect) (18,22).…”