Cost-Effectiveness of Three Poliovirus Immunization Schedules in Shanghai, China

Figures

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  Figure 1. A decision tree model for cost-effectiveness analysis of three polio immunization schedules. The decision tree model had the following hypotheses: (1) 100% coverage of polio immunization in the study population; (2) no self-paid polio-containing vaccines in the study population; (3) no occurrence of VAPP after four-IPV immunization in the study population; (4) cost of cold-chain services, human resources, and administration remain identical across three polio immunization schedules. IPV, inactivated polio vaccine; VAPP, vaccine-associated paralytic poliomyelitis.

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  Figure 2. Cost-effectiveness analysis by using a decision tree model. Total cost of three polio immunization schedules in 2016 was used as the cost, and the sum of LY of local resident births in 2016 was used as the effectiveness. The four-tOPV immunization schedule was cost-effective; in contrast, both the two-IPV-two-bOPV schedule and the four-IPV schedule were cost-ineffective. bOPV, bivalent live attenuated oral polio vaccine; tOPV, trivalent live attenuated oral polio vaccine; IPV, inactivated polio vaccine; LY, life year.

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  Figure 3. Tornado plot of the two-IPV-two-bOPV (a) and the four-IPV (b) immunization schedules, compared to the four-tOPV schedule, using univariate sensitivity analysis. The X-axis represented ICERLY. The incidence of VAPP cases with the four-tOPV schedule, incidence of VAPP cases with the two-IPV-two-bOPV schedule, compensation cost of VAPP cases, and cost of IPV were included in the analysis according to the range of values (Table 1). Positive and negative associations were further determined by the estimation of ICER, which were not presented in the figure. bOPV, bivalent live attenuated oral polio vaccine; tOPV, trivalent live attenuated oral polio vaccine; ICER, incremental cost-effectiveness ratio; IPV, inactivated polio vaccine; LY, life year; VAPP, vaccine-associated paralytic poliomyelitis.

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  Figure 4. One-way sensitivity analysis net benefits graph for three polio immunization schedules. In (a), NMB of IPV-containing schedules was estimated over cost of IPV (X-axis), while that of the four-tOPV schedule was constant. In (b), NMB of the four-tOPV schedule was estimated over the incidence of VAPP cases with the four-tOPV, and those of IPV-containing schedules remained stable. The WTP in the decision tree model was set as CNY 600,000. NMB = total benefit – total cost, in which total benefit = effectiveness (sum of LY per year) × bound of ICERLY (that is WTP) and total cost was the total annual cost of different polio immunization schedules. bOPV, bivalent live attenuated oral polio vaccine; tOPV, trivalent live attenuated oral polio vaccine; IPV, inactivated polio vaccine; NMB, net monetary benefit; VAPP, vaccine-associated paralytic poliomyelitis.