Estimating lives saved by achieving dietary micronutrient adequacy, with a focus on vitamin A intervention programs in Cameroon

Background: We previously compared the potential effects of different intervention strategies for achieving dietary vitamin A (VA) adequacy. The Lives Saved Tool (LiST) permits estimates of lives saved through VA interventions but currently only considers periodic VA supplements (VASs). Objective:We aimed to adapt the LiST method for estimating the mortality impact of VASs to estimate the impact of other VA interventions (e.g., food fortification) on child mortality and to estimate the number of lives saved by VA interventions in 3 macroregions in Cameroon. Methods: We used national dietary intake data to predict the effects of VA intervention programs on the adequacy of VA intake. LiST parameters of population affected fraction and intervention coverage were replaced with estimates of prevalence of inadequate intake and effective coverage (proportion achieving adequate VA intake).We used a model of liver VA stores to derive an estimate of themortality reduction from achieving dietary VA adequacy; this estimate and a conservative assumption of equivalent mortality reduction for VAS and VA intake were applied to projections for Cameroon. Results: There were 2217-3048 total estimated VA-preventable deaths in year 1, with 58% occurring in the North macroregion. The relation between effective coverage and lives saved differed by year andmacroregion due to differences in total deaths, diarrhea burden, and prevalence of lowVA intake. Estimates of lives saved by VASs (the intervention common to both methods) were similar with the use of the adapted method (in 2012: North, 743-1021; South, 280-385; Yaoundé and Douala, 146-202) and the "usual" LiST method (North: 697; South: 381; Yaoundé and Douala: 147). Conclusions: Linking effective coverage estimates with an adapted LiST method permits estimation of the effects of combinations of VA programs (beyond VASs only) on childmortality to aid program planning andmanagement. Rigorous program monitoring and evaluation are necessary to confirm predicted impacts.