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# IV. Applications and Interpretations of the Decision Rule.

If the values of the four parameters in decision rule (9) were known<sup>with</sup> confidence for a specific country or region of a country and the other assumptions of the analysis accepted, application of rule (9) would provide the cost-eireoive integration strategy. Unfortunately none of these parameters is known with precision for any country.<sup>Thls section</sup> applies information from three studies, on Ghana, Java, and the Ivory Coast, in order to<sup>arrive</sup> at tentative estimates of the parameters a, b and tif, life-days-saved per encounter and per vaccination and the intercept of the f5xed-center isocost curve with the e axs. All of these estimates are drawn<sup>together</sup> to illustrate the application and interpreeation of the decision rule in Table 7 at the<sup>end of</sup> the section.

1. Estimates of Healthy Life-Days-Saved Per Vaccination. Table 1 presents two estimates of b, the number of life-days-saved (LDS) per vaccination in an immunization program based on Ghanaian data and assumptions as presented by the Ghana Health Assessment Team (1981).[131 The first estimate of 75.4 LDS per<sup>vaccination</sup> at the bottom of column (7) is based on the theoretical distribution of the various vaccinations in that column. The second estimate of _53.8_ LDS per vaccinatioon at the bottom of column (8) is based on an empirical distrioution of vaccinations observed in neighboring Ivory Coast. Apparently<sup>it is difficult</sup> to maintain the proper ratio of measles vaccines to other vaccines<sup>and to deliver the third doses of the</sup> polio and DPT vaccines. Since the third doses add less<sup>than the average to</sup> LDS, reducing their proportions increases the average of the program. However, since measles vaccination has at least thirty times more impact<sup>on</sup> LDS per vaccination than any of the others, reducing its proportion even slightly has a large negative effect<sup>on the average LDS per vaccine.</sup>

Table 2 presents in columns (8)<sup>and (9) the raw material for developing a</sup> comparable estimate of b based on Javanese data and assumptions as developed and analyzed by a University of Michigan study (Grosse et al, 1979).(14] In e rural population of 50,000, the<sup>Michigan study estimated that</sup> an immunization program consisting of 27,000 administered doses per year would reduce mortality and morbidity to a degree which<sup>is calculated here to</sup> save 1,790 life years through averted deaths and 22,500 days of partial or total disability. Thus on average the Javanese vaccination program is estimated to save 25.0 healthy-life-days per vaccination, a figure which is of the same order of magnitude as the<sup>eatimates for Ghana from Table 1.</sup> However the Javanese immunization program considered by the Michigan study differs in three ways from the immunization program<sup>presented in Table</sup> 1. The Javanese program includes a vaccination of 2100 mothers per year for neonatal tetanus but excludes vaccinations against measles and polio. By referring to the Michigan report,<sup>it is possible to estimate the value of b that</sup> would obtain in Java if the vaccination program resembled that in Table<sup>1.</sup>