Christa L Fischer Walker’s research while affiliated with Johns Hopkins University and other places

Background: The Lives Saved Tool (LiST) is a publicly available and widely used model used to estimate the impact of scaling up interventions on maternal and child health. A strength of the model is that it is continuously updated with country-specific information about intervention coverage, risk factors and causes of death. This paper reports an updated review and meta-analysis on the efficacy of water, sanitation and hygiene (WASH) interventions in reducing diarrhea morbidity among children under the age of five years. Methods: We updated previous LiST systematic reviews for improved WASH interventions according to standard LiST criteria. We sought to identify more recent WASH studies to update LiST efficacy estimates for each WASH intervention on diarrhea morbidity. In addition, we conducted a search to identify studies that reported an effect size for combined improved WASH interventions. For interventions where we found new studies, we conducted a weighted meta-analysis to produce an updated effect size estimate. Results: We did not find new studies demonstrating an effect of improved water source alone on diarrhea morbidity among children under 5 years of age. For improved sanitation, we conducted an updated meta-analysis among 4 studies and found no difference between intervention and control arms (weighted mean difference (WMD) = -5% (95% confidence interval (CI) = -11% to 2%). We identified four trials that assessed the effect of combined interventions targeting improved water, sanitation and hygiene. The weighted mean difference also showed no effect on diarrhea morbidity among children under 5 years of age (WMD = -6%, 95% CI = -15% to 4%). Our updated results for handwashing promotion estimate the effects to results in a 17% reduction in childhood diarrhea morbidity (95% CI = 7% to 27%). Conclusions: Despite widespread acceptance that WASH interventions can improve diarrhea morbidity, the evidence supporting this specifically for children under 5 years of age remains weak. Children interact with the environment in ways that differ from adults and these constant exposures may limit the effect that these WASH interventions can have on diarrhea morbidity.

Background: Childhood diarrhea deaths have declined more than 80% from 1980 to 2015, in spite of an increase in the number of children in low- and middle-income countries (LMIC). Possible drivers of this remarkable accomplishment can guide the further reduction of the half million annual child deaths from diarrhea that still occur. Methods: We used the Lives Saved Tool, which models effects on mortality due to changes in coverage of preventive or therapeutic interventions or risk factors, for 50 LMIC to determine the proximal drivers of the diarrhea mortality reduction. Results: Diarrhea treatment (oral rehydration solution [ORS], zinc, antibiotics for dysentery and management of persistent diarrhea) and use of rotavirus vaccine accounted for 49.7% of the diarrhea mortality reduction from 1980 to 2015. Improvements in nutrition (stunting, wasting, breastfeeding practices, vitamin A) accounted for 38.8% and improvements in water, sanitation and handwashing for 11.5%. The contribution of ORS was greater from 1980 to 2000 (58.0% of the reduction) than from 2000 to 2015 (30.7%); coverage of ORS increased from zero in 1980 to 29.5% in 2000 and more slowly to 44.1% by 2015. To eliminate the remaining childhood diarrhea deaths globally, all these interventions will be needed. Scaling up diarrhea treatment and rotavirus vaccine, to 90% coverage could reduce global child diarrhea mortality by 74.1% from 2015 levels by 2030. Adding improved nutrition could increase that to 89.1%. Finally, adding increased use of improved water sources, sanitation and handwashing could result in a 92.8% reduction from the 2015 level. Conclusions: Employing the interventions that have resulted in such a large reduction in diarrhea mortality in the last 35 years can virtually eliminate remaining childhood diarrhea deaths by 2030.

Introduction Diarrhoea is a leading cause of mortality among young children in India although few receive the recommended treatment. The diarrhoea alleviation through zinc and oral rehydration salts (ORS) therapy (DAZT) team initiated a programme in Gujarat from 2011 to 2013 to increase coverage of these interventions through public and private providers at scale. This study evaluates the economic impact of diarrhoea to caregivers before and after the introduction of zinc and ORS at scale through the DAZT programme. Methods The DAZT programme evaluation took a before-and-after study design using a two-stage clustered cross-sectional survey. Factors associated with the odds of caregivers incurring economic costs and their amounts were evaluated in a two-part modelling approach. Results The DAZT programme lowered unadjusted economic costs to caregivers of treating a diarrhoeal episode from $4.04 to$2.49 in 2 years. Controlling for covariates, analysis showed no association between the programme and a change in odds of incurring an economic cost but did show an association with a reduction in economic cost of $2.15 (95$1.20–$3.11) per diarrhoea episode. A more than 4-fold increase in care-seeking from public community health workers, reduction in care-seeking from higher levels of the health system and reduced spending on drugs besides ORS and zinc may explain these results. Discussion This study found an association between zinc introduction and a reduction in economic burden of diarrhoea treatment to caregivers in underserved rural areas of Gujarat through more efficient patterns of care-seeking and content of care.

Background: Rotavirus is the leading cause of vaccine-preventable diarrhea among children under-five globally. Rotavirus vaccination has been shown to prevent severe rotavirus infections with varying efficacy and effectiveness by region. Methods: We sought to generate updated region-specific estimates of rotavirus vaccine efficacy and effectiveness. We systematically reviewed published vaccine efficacy and effectiveness studies to assess the region- specific effect of rotavirus vaccination on select diarrheal morbidity and mortality outcomes in children under-five years of age. We employed meta-analytic methods to generate pooled effect sizes by Millennium Development Goal (MDG) region. Results: Rotavirus vaccination was both efficacious and effective in preventing rotavirus diarrhea, severe rotavirus diarrhea and rotavirus hospitalizations among children under-five across all regions represented by the 48 included studies. Efficacy against severe rotavirus diarrhea ranged from 90.6% (95% CI: 82.3-95.0%) in the Developed region to 88.4% (67.1-95.9%) in Eastern/Southeastern Asia, 79.6% (71.3-85.5%) in Latin America and the Caribbean, 50.0% (34.4-61.9%) in Southern Asia, and 46.1% (29.1-59.1%) in sub Saharan Africa. Region-specific effectiveness followed a similar pattern. There was also evidence of vaccine efficacy against severe diarrhea and diarrheal hospitalizations. Conclusion: Our findings confirm the protective efficacy and effectiveness of rotavirus vaccination against rotavirus diarrheal outcomes among children under-five globally.

Zinc is a key micronutrient of particular importance during childhood and pregnancy. Zinc deficiency has been linked to increased infection and stunting among children and is a risk factor for adverse pregnancy outcomes and preterm delivery. Targeted interventions have the potential to alleviate the adverse effects of zinc deficiency via therapeutic and preventive supplementation, fortification and biofortification, but implementation is challenging. A growing number of low- and middle- income countries have introduced national policies for zinc treatment of diarrhea among children under 5 years in response to mounting evidence of reduced episode duration and severity as well as reduced incidence in the ensuing months, but coverage remains low in the absence of effective scale-up efforts. Implementation of preventive zinc supplementation in young children has also been slow, despite evidence linking routine daily supplementation and treatment regimens with reductions in stunting and the incidence of diarrhea and pneumonia. Acceptance of other zinc interventions, including traditional fortification, fortification with micronutrient powders and biofortification, is hindered by unclear evidence on efficacy. Additional research is therefore warranted to ascertain the efficacy of delivering zinc through fortified and biofortified foods and in combination with other micronutrients in supplements or powders. Operations research is also necessary to establish best practices for scale-up of therapeutic zinc supplementation for diarrhea.

We propose taking advantage of methodology for missing data to estimate relationships and adjust outcomes in a meta-analysis where a continuous covariate is differentially categorized across studies. The proposed method incorporates all available data in an implementation of the expectation-maximization algorithm. We use simulations to demonstrate that the proposed method eliminates bias that would arise by ignoring a covariate and generalizes the meta-analytical approach for incorporating covariates that are not uniformly categorized. The proposed method is illustrated in an application for estimating diarrhea incidence in children aged ≤59 months.

To address inadequate coverage of oral rehydration salts (ORS) and zinc supplements for the treatment of diarrhea among children under–five, the Diarrhea Alleviation through Zinc and ORS Treatment (DAZT) program was carried out from 2011–2013 in Gujarat and from 2011–2014 in Uttar Pradesh (UP), India. The program focused on improving the diarrhea treatment practices of public and private sector providers. We conducted cross–sectional household surveys in program districts at baseline and endline and constructed state–specific logistic regression models with generalized estimating equations to assess changes in ORS and zinc treatment during the program period. Between baseline and endline, zinc coverage increased from 2.5% to 22.4% in Gujarat and from 3.1% to 7.0% in UP; ORS coverage increased from 15.3% to 39.6% in Gujarat but did not change in UP. In comparison to baseline, children with diarrhea in the two–weeks preceding the endline survey had higher odds of receiving zinc treatment in both Gujarat (odds ratio, OR = 11.2; 95% confidence interval (CI) 6.4–19.3) and UP (OR = 2.4; 95% CI 1.4–3.9), but the odds of receiving ORS only increased in Gujarat (OR = 3.6; 95% CI 2.7–4.8; UP OR = 0.9; 95% CI 0.7–1.2). Seeking care outside the home, especially from a public sector source, was associated with higher odds of receiving ORS and zinc. Conclusions During the duration of the DAZT program, there were modest improvements in the treatment of diarrhea among young children. Future programs should build upon and accelerate this trend with continued investment in public and private sector provider training and supply chain sustainability, in addition to targeted care–giver demand generation activities.

There is limited evidence on adherence to the recommended dose and duration of zinc supplementation for diarrheal episodes in children under five years of age. In selected districts of Uttar Pradesh, India, we sought to assess adherence to the nationally advised zinc treatment regimen (ie, 10 mg/day for ages 2–6 months and 20 mg/day for ages 7–59 months for 14 days) among caregivers of zinc–prescribed children. We identified and conducted follow–up visits to children advised zinc for the treatment of diarrhea. At the initial visit, we collected data on the treatment instructions received from providers. Caregivers were asked to record treatments administered on a pictorial tracking form and were asked to retain all packaging for collection at follow–up. We quantified the average dose and duration of zinc therapy and built logistic regression models to assess the factors associated with caregiver adherence to national guidelines. Caregivers administered zinc for an average of 10.7 days (standard deviation (SD) = 3.9 days; median = 13 days), and 47.8% continued treatment for the complete 14 days. Among children receiving zinc syrups and tablets respectively, the age appropriate dose was received by 30.8% and 67.3%. Adherence to age appropriate dose and continuation of zinc for 14 days were highly associated with having received appropriate provider instructions. Our results indicate moderate–to–good adherence to national zinc treatment guidelines for diarrhea among caregivers in rural India. Our findings also highlight the importance of provider guidance in ensuring adherence to zinc dose and duration. Programs aiming to scale–up zinc treatment for childhood diarrhea should train providers to successfully communicate dosing instructions to caregivers, while also addressing the tendency of caregivers to terminate treatment once a child appears to have recovered from an acute diarrheal episode.

In Bihar, India, a new initiative to enhance diarrhea treatment with zinc and ORS in the public sector was rolled out in selected districts. We conducted an external evaluation to measure changes in diarrhea careseeking and treatment in intervention districts. We conducted baseline and endline household surveys among caregivers of children 2-59 months of age. We calculated summary statistics for household characteristics, knowledge, careseeking and treatments given to children with a diarrhea episode in the last 14 days and built logistic regression models to compare baseline and endline values. Caregivers named a public health center as an appropriate source of care for childhood diarrhea more often at endline (71.3%) compared to baseline (38.4%) but did not report increased careseeking to public sector providers for the current diarrhea episode. In logistic regression analyses, the odds of receiving zinc, with or without oral rehydration salts (ORS), increased at endline by more than 2.7 as compared to baseline. Children who were taken to the public sector for care were more likely to receive zinc (odds ratio, OR = 3.93) and zinc in addition to ORS (OR = 6.10) compared to children who were not taken to the public sector. Coverage of zinc and ORS can improve with public sector programs targeted at training and increasing product availability, but demand creation may be needed to increase public sector careseeking in areas where the private sector has historically provided much of the care.