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Choosing an optimum set of child health interventions for maximum mortality impact is important within resource-poor policy environments. The Lives Saved Tool (LiST) is a computer model that estimates the mortality and stillbirth impact of scaling up proven maternal and child health interventions. To model the impacts on child health, LiST uses the demographic engine of Spectrum (DemProj), which calculates the numbers of deaths disaggregated by age band, while using neonatal, infant, and under-five mortality rates from LiST. It then overlays the AIDS mortality directly related to children from the AIDS Impact Module (AIM), based upon the prevalence of AIDS among the entire population to calculate the total number of deaths due to AIDS. The non-AIDS individual causes of death are then overlayed on all of the non-AIDS deaths in children in the neonatal period and the 1-59 month period.
LiST estimates the mortality impact via five age bands: 0 months, 1-5 months, 6-11 months, 12-23 months, and 24-59 months. For each of these age bands, reductions in cause-specific mortality are estimated by applying intervention effectivenesses and affected fractions to intervention coverage changes. The impacts of interventions are calculated separately for eight causes of death in the neonatal period, and nine causes of death in the 1-59 month period. Corrections are then made to this simple equation to correct for the impact of coverage achieved prior to the projection period. The impact of interventions are calculated in groups such that periconceptual, antenatal, and childbirth interventions, sequentially, have the first "opportunity" to prevent mortality, with preventive interventions impacting mortality next and leaving those that are more curative in nature to reduce the remaining mortality that is not reduced. Then each child who is "saved" is then capable of dying of other causes during the subsequent age period.
Simultaneously, nutrition interventions can impact either nutritional status or directly impact mortality. In the former case, LiST acts as a cohort model where current nutritional statuses such as stunting or intrauterine growth restriction impact the probability of stunting as the cohort ages. LiST links with DemProj to estimate the deaths and deaths averted due to the reductions in mortality rates.
In addition, AIM calculates the impact of PMTCT, Cotrimoxazole, and ART for children and then feeds these directly back into the LiST model as deaths averted by these interventions. The Family Planning (FamPlan) and DemProj modules can also feed into the LiST model via changes in the number of births, resulting in varying numbers of child deaths upon which to apply the intervention impacts.
LiST also estimates the impact of interventions on maternal mortality. The calculations are very similar to those for child mortality. One difference is that all women aged 15-49 are treated as a single group in the calculations, and interventions act directly on one or more of the nine causes of death (i.e., none affect an intermediate nutrition status). Family planning, although not an intervention in LiST, may also impact maternal mortality by reducing the incidence of abortion, which is a maternal cause of death in the LiST model. The reductions in maternal mortality are translated into maternal mortality ratios, which are then translated into maternal deaths and maternal deaths averted via live births calculated in DemProj.
Finally, LiST estimates the impact of interventions on stillbirths. Different from the other outputs, the reductions are analyzed by when the stillbirth occurs in pregnancy – either antepartum or intrapartum. As with maternal mortality, stillbirth reductions are translated into stillbirth rates, and stillbirths via pregnancies in DemProj.
For more information on the general methodology of LiST please see Walker N, Tam Y, Friberg I. Overview of the Lives Saved Tool (LiST). BMC Public Health 2013; 13(Suppl 3): S1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3847271/.
For more information on the calculations within LiST, please see Winfrey W, McKinnon R, Stover J. Methods used in the Lives Saved Tool (LiST). BMC Public Health 2011, 11(Suppl 3): S32. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3231906/.
Please visit www.livessavedtool.org for a complete list of papers using LiST and other resources. |
