Regression tree analysis of 10,000 Monte Carlo simulations sampling across the uncertainty in all parameters.

The leaves of the tree end in ovals that show the mean cost per DALY of maternal influenza vaccine among all simulations whose parameters follow the paths described in the proximal branches. Further partitioning of this pruned, cross-validated tree did not reduce generalization error. Parameters affecting infant influenza are shown in shades of blue, while parameters affecting influenza in women are shown in purple. Cost-effectiveness ratios < 1x per-capita GDP in Mali are shown in green, those between 1x and 3x per-capita GDP in Mali are shown in yellow, those >3x per-capita GDP in Mali are shown in red. LCI: Lab-confirmed influenza; CFR: case-fatality ratio; VE: vaccine efficacy.