Fig. 1

Sensitivity analysis (Cost per patient, varying reductions in vertical referrals) (Minimal scenario: 19% and 8% reduction of upward referrals from private and public PHCs, respectively; Medium scenario: 37% and 15% reduction of upward referrals from private and public PHCs, respectively; Maximal scenario: 56% and 23.1% reduction of upward referrals from private and public PHCs.). *US$1 = 14,212 rupiah (Bank Indonesia, June 28, 2019)