Zaid Bhatti

A century of trends in adult human height

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. DOI: http://dx.doi.org/10.7554/eLife.13410.001

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study.

BACKGROUND International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries. METHODS Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated. FINDINGS Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations. INTERPRETATION We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems. FUNDING The Lowitja Institute.

Geographical and socioeconomic inequalities in women and children's nutritional status in Pakistan in 2011: an analysis of data from a nationally representative survey

Summary Background Pakistan has one of the highest levels of child and maternal undernutrition worldwide, but little information about geographical and socioeconomic inequalities is available. We aimed to analyse anthropometric indicators for childhood and maternal nutrition at a district level in Pakistan and assess the association of nutritional status with food security and maternal and household socioeconomic factors. Methods We used data from the 2011 Pakistan National Nutrition Survey, which included anthropometric measurements for 33 638 children younger than 5 years and 24 826 women of childbearing age. We estimated the prevalences of stunting, wasting, and underweight among children and of underweight, overweight, and obesity in women for all 143 districts of Pakistan using a Bayesian spatial technique. We used a mixed-effect linear model to analyse the association of nutritional status with individual and household sociodemographic factors and food security. Findings Stunting prevalence in Pakistans districts ranged between 22% (95% credible interval 19–26) and 76% (69–83); the lowest figures for wasting and underweight were both less than 2·5% and the highest were 42% (34–50) for wasting and 54% (49–59) for underweight. In 106 districts, more women were overweight than were underweight; in 49 of these districts more women were obese than were underweight. Children were better nourished if their mothers were taller or had higher weight, if they lived in wealthier households, and if their mothers had 10 or more years of education. Severe food insecurity was associated with worse nutritional outcomes for both children and women. Interpretation We noted large social and geographical inequalities in child and maternal nutrition in Pakistan, masked by national and provincial averages. Pakistan is also beginning to face the concurrent challenge of high burden of childhood undernutrition and overweight and obesity among women of reproductive age. Planning, implementation, and evaluation of programmes for food and nutrition should be based on district-level needs and outcomes. Funding Bill & Melinda Gates Foundation, Grand Challenges Canada, UK Medical Research Council.

Achieving maternal and child health gains in Afghanistan: a Countdown to 2015 country case study

BACKGROUND After the fall of the Taliban in 2001, Afghanistan experienced a tumultuous period of democracy overshadowed by conflict, widespread insurgency, and an inflow of development assistance. Although there have been several cross-sectional assessments of health gains over the last decade, there has been no systematic analysis of progress and factors influencing maternal and child health in Afghanistan. METHODS We undertook a comprehensive, systematic assessment of reproductive, maternal, newborn, and child health in Afghanistan over the last decade. Given the paucity of high-quality data before 2001, we relied mainly on 11 nationally representative surveys conducted between 2003 and 2013. We estimated national and subnational time trends for key reproductive, maternal, and child health indicators, and used linear regression methods to determine predictors of change in health-care service use. All analyses were weighted for sampling and design effects. Additional information was collated and analysed about health system performance from third party surveys and about human resources from the Afghan Ministry of Public Health. FINDINGS Between 2003 and 2015, Afghanistan experienced a 29% decline in mortality of children younger than 5 years. Although definite reductions in maternal mortality remain uncertain, concurrent improvements in essential maternal health interventions suggest parallel survival gains in mothers. In a little over a decade (2003-13 inclusive), coverage of several maternal care interventions increased-eg, for antenatal care (16% to 53%), skilled birth attendance (14% to 46%), and births in a health facility (13% to 39%). Childhood vaccination coverage rates for the basic vaccines from the Expanded Programme of Immunisation (eg, BCG, measles, diphtheria-tetanus-pertussis, and three doses of polio) doubled over this period (about 40% to about 80%). Between 2005 and 2013, the number of deployed facility and community-based health-care professionals also increased, including for nurses (738 to 5766), midwives (211 to 3333), general physicians (403 to 5990), and community health workers (2682 to 28 837). Multivariable analysis of factors contributing to overall changes in skilled birth attendance and facility births suggests independent contributions of maternal literacy, deployment of community midwives, and proximity to a facility. INTERPRETATION Despite conflict and poverty, Afghanistan has made reasonable progress in its reproductive, maternal, newborn, and child health indicators over the last decade based on contributions of factors within and outside the health sector. However, equitable access to health care remains a challenge and present delivery models have high transactional costs, affecting sustainability. To maintain and further accelerate health and development gains, future strategies in Afghanistan will need to focus on investments in improving social determinants of health and targeted cost-effective interventions to address major causes of maternal and newborn mortality. FUNDING US Fund for UNICEF under the Countdown to 2015 for Maternal, Newborn, and Child Survival grant from the Bill & Melinda Gates Foundation, and from the Government of Canada, Foreign Affairs, Trade and Development Canada. Additional direct and in-kind support was received from the UNICEF Country Office Afghanistan, the Centre for Global Child Health, the Hospital for Sick Children, Toronto, the Aga Khan University, and Mother and Child Care Trust (Pakistan).

Immunogenicity of poliovirus vaccines in chronically malnourished infants: a randomized controlled trial in Pakistan.

Reaching high population immunity against polioviruses (PV) is essential to achieving global polio eradication. Efficacy of oral poliovirus vaccine (OPV) varies and is lower among children living in tropical areas with impoverished environments. Malnutrition found as a risk factor for lower serological protection against PV. We compared whether inactivated polio vaccine (IPV) can be used to rapidly close the immunity gap among chronically malnourished (stunted) infants in Pakistan who will not be eligible for the 14 week IPV dose in routine EPI schedule. A phase 3, multicenter 4-arm randomized controlled trial conducted at five Primary Health Care (PHC) centers in Karachi, Pakistan. Infants, 9–12 months were stratified by length for age Z score into chronically malnourished and normally nourished. Infants were randomized to receive one dose of either bivalent OPV (bOPV) alone or bOPV + IPV. Baseline seroprevalence of PV antibodies and serum immune response to study vaccine dose were assessed by neutralization assay. Vaccine PV shedding in stool was evaluated 7 days after a bOPV challenge dose. Sera and stool were analyzed from 852/928 (92%) enrolled children. At baseline, the seroprevalence was 85.6% (n = 386), 73.6% (n = 332), and 70.7% (n = 319) in malnourished children against PV types 1, 2 and 3 respectively; and 94.1% (n = 448), 87.0% (n = 441) and 83.6% (n = 397) in the normally nourished group (p < 0.05). Children had previously received 9–10 doses of bOPV (80%) or tOPV (20%). One dose of IPV + bOPV given to malnourished children increased their serological protection (PV1, n = 201, 97.6%; PV2, n = 198, 96.1% and PV3, n = 189, 91.7%) to parity with normally nourished children who had not received IPV (p = <0.001). Seroconversion and boosting for all three serotypes was significantly more frequent in children who received IPV + bOPV than in those with bOPV only (p < 0.001) in both strata. Shedding of polioviruses in stool did not differ between study groups and ranged from 2.4% (n = 5) to 7.1% (n = 15). In malnourished children the shedding was reduced after bOPV + IPV compared to bOPV only. Chronically malnourished infants were more likely to be unprotected against polioviruses than normal infants. bOPV + IPV helped close the immunity gap better than bOPV alone.

Validation of Verbal Autopsy Tool for Ascertaining the Causes of Stillbirth

Objective To assess performance of the WHO revised verbal autopsy tool for ascertaining the causes of still birth in comparison with reference standard cause of death ascertained by standardized clinical and supportive data. Methods All stillbirths at a tertiary hospital in Karachi, Pakistan were prospectively recruited into study from August 2006- February 2008. The reference standard cause of death was established by two senior obstetricians within 48 hours using the ICD coding system. Verbal autopsy interviews using modified WHO tool were conducted by trained health workers within 2- 6 weeks of still birth and the cause of death was assigned by second panel of obstetricians. The performance was assessed in terms of sensitivity, specificity and Kappa. Results There were 204 still births. Of these, 80.8% of antepartum and 50.5% of intrapartum deaths were correctly diagnosed by verbal autopsy. Sensitivity of verbal autopsy was highest 68.4%, (95%CI: 46-84.6) for congenital malformation followed by obstetric complication 57.6%, (95%CI: 25-84.2). The specificity for all major causes was greater than 90%. The level of agreement was high (kappa=0.72) for anomalies and moderate (k=0.4) for all major causes of still birth, except asphyxia. Conclusion Our results suggest that verbal autopsy has reasonable validity in identifying and discriminating between causes of stillbirth in Pakistan. On the basis of these findings, we feel it has a place in resource constrained areas to inform strategic planning and mobilization of resources to attain Millennium Development Goals.

Demographic, Socioeconomic, and Health Characteristics of the MAL-ED Network Study Site in Rural Pakistan

The Pakistan study site of the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study is located in Molhan union council of Naushahro Feroze district in the Sindh province. The study site is located in a rural district, where the majority of the population has an agrarian livelihood. Most families are nuclear families and the average household has 7 persons. More than half the women in the region have no formal education, and the median parity is 6. Only 48%-61% of the households across the district, province, and country have access to an improved toilet facility. Similar to the provincial and national estimates, the district has a low rate of exclusive breastfeeding at 6 months, and the prevalence of prelacteal feeding is high. There is also a high proportion of malnourished children. In addition, the acute respiratory infection and diarrheal illness burden and the mortality rates in children <5 years old in the district are high but comparable with the provincial and national estimates. Overall, the district is representative of rural populations at the regional and national level in terms of demographics, socioeconomic status, and general health and mortality indicators.

Prevalence and Predictors of Iron Deficiency Anemia in Children under Five Years of Age in Pakistan, A Secondary Analysis of National Nutrition Survey Data 2011–2012

Background Iron deficiency Anemia (IDA) in children is a recognized public health problem that impacts adversely on child morbidity, mortality and impairs cognitive development. In Pakistan information on the true prevalence and predictors of IDA is limited. This study sought to investigate IDA in children under five years of age using data from a nationally representative stratified cross-sectional survey. Methods Secondary analysis was performed on the National Nutrition Survey in Pakistan 2011–2012. We used a pre-structured instrument to collect socio demographic and nutritional data on mothers and children. We also collected Anthropometric measurements and blood samples for micronutrient deficiencies. IDA was defined as having both haemoglobin levels of <110 g/L and ferritin levels of < 12 μg/L. Data analysis was performed by applying univariate and multivariate techniques using logistic regression through SPSS. Findings A total of 7138 children aged between 6–59 months were included in the analysis. The prevalence of IDA was 33.2%. In multivariate regression analysis adjusted odds ratios (AOR) were calculated. Age < 24 months (AOR 1.40, 95% CI 1.18–1.55 p <0.05), stunting (AOR 1.42 CI 1.23–1.63 p<0.05), presence of clinical anemia (AOR 5.69 CI 4.93–6.56 p<0.05), having a mother with IDA (AOR 1.72 CI 1.47–2.01 p<0.05) and household food insecurity (AOR 1.20 CI 1.10–1.40 P<0.05) were associated with IDA. Living in a rural area (AOR 0.77 CI 0.65–0.90 p<0.05) and being a female child (AOR 0.87 CI 0.76–0.98 p<0.05) were associated with reduced odds of IDA. Conclusion The prevalence of IDA amongst Pakistani children represents a moderate burden that disproportionately affects the youngest, growth retarded children, affected children are more likely to have mothers with IDA and live in areas where food security is lacking. National efforts to alleviate the burden of IDA should involve both short term vertical programs such as iron supplementation and long term horizontal programs including wheat flour fortification.

Progress and priorities for reproductive, maternal, newborn, and child health in Kenya: a Countdown to 2015 country case study

Summary Background Progress in reproductive, maternal, newborn, and child health (RMNCH) in Kenya has been inconsistent over the past two decades, despite the global push to foster accountability, reduce child mortality, and improve maternal health in an equitable manner. Although several cross-sectional assessments have been done, a systematic analysis of RMNCH in Kenya was needed to better understand the push and pull factors that govern intervention coverage and influence mortality trends. As such, we aimed to determine coverage and impact of key RMNCH interventions between 1990 and 2015. Methods We did a comprehensive, systematic assessment of RMNCH in Kenya from 1990 to 2015, using data from nationally representative Demographic Health Surveys done between 1989 and 2014. For comparison, we used modelled mortality estimates from the UN Inter-Agency Groups for Child and Maternal Mortality Estimation. We estimated time trends for key RMNCH indicators, as defined by Countdown to 2015, at both the national and the subnational level, and used linear regression methods to understand the determinants of change in intervention coverage during the past decade. Finally, we used the Lives Saved Tool (LiST) to model the effect of intervention scale-up by 2030. Findings After an increase in mortality between 1990 and 2003, there was a reversal in all mortality trends from 2003 onwards, although progress was not substantial enough for Kenya to achieve Millennium Development Goal targets 4 or 5. Between 1990 and 2015, maternal mortality declined at half the rate of under-5 mortality, and changes in neonatal mortality were even slower. National-level trends in intervention coverage have improved, although some geographical inequities remain, especially for counties comprising the northeastern, eastern, and northern Rift Valley regions. Disaggregation of intervention coverage by wealth quintile also revealed wide inequities for several health-systems-based interventions, such as skilled birth assistance. Multivariable analyses of predictors of change in family planning, skilled birth assistance, and full vaccination suggested that maternal literacy and family size are important drivers of positive change in key interventions across the continuum of care. LiST analyses clearly showed the importance of quality of care around birth for maternal and newborn survival. Interpretation Intensified and focused efforts are needed for Kenya to achieve the RMNCH targets for 2030. Kenya must build on its previous progress to further reduce mortality through the widespread implementation of key preventive and curative interventions, especially those pertaining to labour, delivery, and the first day of life. Deliberate targeting of the poor, least educated, and rural women, through the scale-up of community-level interventions, is needed to improve equity and accelerate progress. Funding US Fund for UNICEF, Bill & Melinda Gates Foundation.

Zinc supplementation fails to increase the immunogenicity of oral poliovirus vaccine: a randomized controlled trial.

BACKGROUND Polio eradication remains a challenge in Pakistan and the causes for the failure to eradicate poliomyelitis are complex. Undernutrition and micronutrient deficiencies, especially zinc deficiency, are major public health problems in Pakistan and could potentially affect the response to enteric vaccines, including oral poliovirus vaccine (OPV). OBJECTIVE To assess the impact of zinc supplementation among infants on immune response to oral poliovirus vaccine (OPV). METHODS A double-blind, randomized placebo-controlled trial was conducted in newborns (aged 0-14 days). Subjects were assigned to either receive 10mg of zinc or placebo supplementation daily for 18 weeks. Both groups received OPV doses at birth, at 6 weeks, 10 weeks and 14 weeks. Data was collected on prior immunization status, diarrheal episodes, breastfeeding practices and anthropometric measurements at recruitment and at 6 and 18 weeks. Blood samples were similarly collected to determine the antibody response to OPV and for micronutrient analysis. Logistic regression was used to determine the relationship between seroconversion and zinc status. RESULTS Overall, 404 subjects were recruited. At recruitment, seropositivity was already high for poliovirus (PV) serotype 1 (zinc: 91.1%; control: 90.5%) and PV2 (90.0%; 92.7%), with lower estimates for PV3 (70.0%; 64.8%). By week 18, the proportion of subjects with measured zinc levels in the normal range (i.e. ≥60 μg/dL) was significantly greater in the intervention group compared to the control group (71.9%; 27.4%; p<0.001). No significant difference in seroconversion was demonstrated between the groups for PV1, PV2, or PV3. CONCLUSIONS There was no effect of zinc supplementation on OPV immunogenicity. These conclusions were confirmed when restricting the analysis to those with measured higher zinc levels.