The Lives Saved Tool (LiST) as a model for diarrhea mortality reduction

BACKGROUND: Diarrhea is a leading cause of morbidity and mortality among children under five years of age. The Lives Saved Tool (LiST) is a model used to calculate deaths averted or lives saved by past interventions and for the purposes of program planning when costly and time consuming impact studies are not possible. DISCUSSION: LiST models the relationship between coverage of interventions and outputs, such as stunting, diarrhea incidence and diarrhea mortality. Each intervention directly prevents a proportion of diarrhea deaths such that the effect size of the intervention is multiplied by coverage to calculate lives saved. That is, the maximum effect size could be achieved at 100% coverage, but at 50% coverage only 50% of possible deaths are prevented. Diarrhea mortality is one of the most complex causes of death to be modeled. The complexity is driven by the combination of direct prevention and treatment interventions as well as interventions that operate indirectly via the reduction in risk factors, such as stunting and wasting. Published evidence is used to quantify the effect sizes for each direct and indirect relationship. Several studies have compared measured changes in mortality to LiST estimates of mortality change looking at different sets of interventions in different countries. While comparison work has generally found good agreement between the LiST estimates and measured mortality reduction, where data availability is weak, the model is less likely to produce accurate results. LiST can be used as a component of program evaluation, but should be coupled with more complete information on inputs, processes and outputs, not just outcomes and impact. SUMMARY: LiST is an effective tool for modeling diarrhea mortality and can be a useful alternative to large and expensive mortality impact studies. Predicting the impact of interventions or comparing the impact of more than one intervention without having to wait for the results of large and expensive mortality studies is critical to keep programs focused and results oriented for continued reductions in diarrhea and all-cause mortality among children under five years of age

Rotavirus vaccine and diarrhea mortality: quantifying regional variation in effect size

<p>Abstract</p> <p>Background</p> <p>Diarrhea mortality remains a leading cause of child death and rotavirus vaccine an effective tool for preventing severe rotavirus diarrhea. New data suggest vaccine efficacy may vary by region.</p> <p>Methods</p> <p>We reviewed published vaccine efficacy trials to estimate a regional-specific effect of vaccine efficacy on severe rotavirus diarrhea and hospitalizations. We assessed the quality of evidence using a standard protocol and conducted meta-analyses where more than 1 data point was available.</p> <p>Results</p> <p>Rotavirus vaccine prevented severe rotavirus episodes in all regions; 81% of episodes in Latin America, 42.7% of episodes in high-mortality Asia, 50% of episodes in sub-Saharan Africa, 88% of episodes low-mortality Asia and North Africa, and 91% of episodes in developed countries. The effect sizes observed for preventing severe rotavirus diarrhea will be used in <it>LiST</it> as the effect size for rotavirus vaccine on rotavirus-specific diarrhea mortality.</p> <p>Conclusions</p> <p>Vaccine trials have not measured the effect of vaccine on diarrhea mortality. The overall quality of the evidence and consistency observed across studies suggests that estimating mortality based on a severe morbidity reduction is highly plausible.</p

Standards for CHERG reviews of intervention effects on child survival

Background The Lives Saved Tool (LiST) uses estimates of the effects of interventions on cause-specific child mortality as a basis for generating projections of child lives that could be saved by increasing coverage of effective interventions. Estimates of intervention effects are an essential element of LiST, and need to reflect the best available scientific evidence. This article describes the guidelines developed by the Child Health Epidemiology Reference Group (CHERG) that are applied by scientists conducting reviews of intervention effects for use in LiST. Methods The guidelines build on and extend those developed by the Cochrane Collaboration and the Working Group for Grading of Recommendations Assessment, Development and Evaluation (GRADE). They reflect the experience gained by the CHERG intervention review groups in conducting the reviews published in this volume, and will continue to be refined through future reviews. Presentation of the guidelines Expected products and guidelines are described for six steps in the CHERG intervention review process: (i) defining the scope of the review; (ii) conducting the literature search; (iii) extracting information from individual studies; (iv) assessing and summarizing the evidence; (v) translating the evidence into estimates of intervention effects and (vi) presenting the results. Conclusions The CHERG intervention reviews represent an ambitious effort to summarize existing evidence and use it as the basis for supporting sound public health decision making through LiST. These efforts will continue, and a similar process is now under way to assess intervention effects for reducing maternal mortalit

Does Age Affect the Response to Zinc Therapy for Diarrhoea in Bangladeshi Infants?

The benefit of zinc for the treatment of diarrhoea in a cluster-randomized trial of children, aged 3–59 months, living in rural Bangladesh was previously reported. Here, the benefits of zinc stratified by age—3–5 months, 6–11 months, and 12–59 months—are reported. Although the sample sizes in the stratified groups were too small to detect statistical significance in the 3–5-month and 6–11-month age-groups, the trends suggest that there may be a benefit of zinc for the treatment of diarrhoea on the duration of diarrhoea and on subsequent morbidity and mortality. Additional research is needed to better understand the effect of zinc for the treatment of diarrhoea among infants aged less than six months

Effect of HIV/AIDS and Malaria on the Context for Introduction of Zinc Treatment and Low-osmolarity ORS for Childhood Diarrhoea*

Diarrhoea was estimated to account for 18% of the estimated 10.6 million deaths of children aged less than five years annually in 2003. Two—Africa and South-East Asia—of the six regions of the World Health Organization accounted for approximately 40% and 31% of these deaths respectively, or almost three-quarters of the global annual deaths of children aged less than five years attributable to diarrhoea. Much of the effort to roll out low-osmolarity oral rehydration solution (ORS) and supplementation of zinc for the management of diarrhoea accordingly is being devoted to sub-Saharan Africa and to South and South-East Asia. A number of significant differences exist in diarrhoea-treatment behaviours and challenges of the public-health systems between Africa and Asia. The differences in rates of ORS use are the most common indicator of treatment of diarrhoea and vary dramatically by and within region and may significantly influence the roll-out strategy for zinc and low-osmolarity ORS. The prevalence of HIV/AIDS and the endemi-city of malaria also differ greatly between regions; both the diseases consume the attention and financial commitment of public-health programmes in regions where rates are high. This paper examined how these differences could affect the context for the introduction of zinc and low-osmolarity ORS at various levels, including the process of policy dialogue with local decision-makers, questions to be addressed in formative research, implementation approaches, and strategies for behaviour-change communication and training of health workers

Quantifying the Association between Campylobacter Infection and Guillain-Barré Syndrome: A Systematic Review

Guillain-Barré Syndrome (GBS) is a neurologic disease that causes ascending paralysis and is triggered by a preceding bacterial or viral infection. Several studies have shown that patients with GBS have a recent history of infection due to Campylobacter jejuni. A literature review of published studies that reported rates of Campylobacter infection before or in conjunction with GBS was done. These reported data were used for calculating the proportion of GBS cases who tested positive for Campylobacter compared to the control population and the incidence of GBS among patients infected with Campylobacter. Results of the analysis suggest that 31% of 2,502 GBS cases included in these papers are attributable to Campylobacter infection

Diarrhea as a risk factor for acute lower respiratory tract infections among young children in low income settings

Diarrhea and acute lower respiratory tract infections (ALRI) are leading causes of morbidity and mortality among children under 5 years of age. We sought to quantify the correlation of diarrhea and respiratory infections within an individual child and to determine if infection with one illness increases the risk of infection with the other during the same time period