Dynamic aspects of ORF1ab and N RNA cycle threshold values among COVID-19 patients in China.

The dynamics of viral loads among COVID-19 patients in Changzhou, China were evaluated using dynamic random effects models. The models were estimated by maximum likelihood methods allowing for between and within patient variations. Statistical criteria were developed for focusing on viral RNAs for clinical decision making. The empirical results showed that inflammation among patients were significant predictors of cycle threshold values for ORF1ab and N RNAs. Moreover, within subject variations were higher in Ct values of ORF1ab RNA indicating that assessment of N RNA may be adequate in resource-poor settings. The inter-relationships between ORF1ab and N RNAs were investigated and the need for developing comprehensive models for viral load dynamics is emphasized.

Climate change, demographic pressures and global sustainability.

This article emphasizes the need for broader approaches for formulating policies for mitigating the effects of climate change especially in the contexts of agricultural decisions, and population health and migration. Constraints imposed by rapid population growth in developing countries for achievement of Sustainable Development Goals are discussed and evidence is presented on "unwanted" fertility from India. Second, comparisons are made for India during 2002-2016 for average well depths in 495 districts and terrestrial water storage anomalies assessed via GRACE satellites for 274 1°â€¯× 1° grids using estimated parameters from dynamic random effects models. Lastly, migration patterns especially of the highly educated from 39 sending countries to OECD countries during 2000-2010 are analyzed using dynamic random effects models and total fertility rates were significantly associated with higher migration rates for the highly educated. Implications of the empirical evidence for enhancing global sustainability are discussed.

Dietary Modifications and Lipid Accumulation Product Are Associated with Systolic and Diastolic Blood Pressures in the Women's Health Trial: Feasibility Study in Minority Populations.

PURPOSE OF REVIEW: Approximately 65% of adults over 60 years in the USA are hypertensive. Poor dietary habits and sedentary lifestyles are fueling the hypertension epidemic. The effects of higher intakes of fruits and vegetables and whole-grain products on systolic and diastolic blood pressures were analyzed using data at baseline, 6 months, and 12 months on 349 and 573 subjects, respectively, in the control and intervention groups of the Women's Health Trial: Feasibility Study in Minority Populations. RECENT FINDINGS: Models for systolic and diastolic blood pressures have been estimated using cross-sectional and longitudinal data in different settings. However, it is important to estimate comprehensive dynamic random effects models that take into account inter-relationships between systolic and diastolic blood pressures as well as the effects of dietary intakes and biomarkers for making robust inferences. There were significantly greater reductions (P < 0.05) between baseline and 12 months in systolic and diastolic blood pressures in the intervention group. Second, ratios of α-tocopherol to energy intakes were negatively and significantly associated with systolic and diastolic blood pressures in the intervention group. Third, the lipid accumulation product was positively associated with systolic and diastolic blood pressures in the control and intervention groups. The estimated coefficients of diastolic and systolic blood pressure variables in the respective models for systolic and diastolic blood pressures showed that combining the two measures as pulse pressure can lead to misleading inferences. Overall, dietary interventions promoting higher consumption of fruits and vegetables and whole-grain products can help lower blood pressures of women in the USA.

Health status, food insecurity, and time allocation patterns of patients with AIDS receiving antiretroviral treatment in South Africa.

For patients with AIDS receiving antiretroviral treatment (ART) in South Africa via public clinics, improvements in nutritional status and economic productivity are likely to depend on adherence to drug regimen and quality of diet reflected in protein and micronutrient intakes. This study randomized 643 patients receiving ART from public clinics in the Free State Province into a Control group, a treatment group receiving adherence support, and a treatment group receiving adherence support and a nutritious food supplement. The data on food insecurity levels and time spent on various activities were analyzed for assessing the impact of the intervention programs. The main results were, first, changes between survey rounds 1 and 3 were significant at the 5% level for outcomes such as food insecurity levels and CD4 cell counts. Moreover, there was a significant reduction in food insecurity levels of patients with BMI less than 25 who received the nutritious food supplement. Second, the estimated parameters from models for patients' food insecurity levels showed that household incomes were significantly associated with lower food insecurity levels. Third, patients' BMI was a significant predictor of time spent on sedentary, moderate and overall activity levels, and it was important to separately evaluate the effects of BMI for under-weight and over-weight patients. Overall, the results indicated the need for reducing food insecurity levels, and for designing different interventions for under-weight and over-weight patients with AIDS for enhancing their labor productivity.

A LONGITUDINAL ANALYSIS OF INTERNAL MIGRATION, DIVORCE AND WELL-BEING IN CHINA.

The rapid economic growth in China has been accompanied by increases in internal migration as well as marital dissolution. Using longitudinal data from China Health and Nutrition Surveys covering over 19,000 individuals during 1989-2011, this study modelled the inter-relationships between internal migration, divorce and individual well-being, tackling conceptual and methodological aspects such as the joint determination of variables. First, random effects probit models showed that the migration periods of husbands and wives significantly increased their respective chances of divorce. Second, results from dynamic random effects models for self-reported health showed different effects of separation periods for husbands and wives; divorce did not significantly lower health status. Third, dynamic models for systolic and diastolic blood pressures showed significant effects of migration durations of husbands and wives; men had lower systolic blood pressure following divorce thereby indicating beneficial effects for unhappily married couples. The implications of the findings are discussed.

Statistical methodologies to pool across multiple intervention studies.

Combining and analyzing data from heterogeneous randomized controlled trials of complex multiple-component intervention studies, or discussing them in a systematic review, is not straightforward. The present article describes certain issues to be considered when combining data across studies, based on discussions in an NIH-sponsored workshop on pooling issues across studies in consortia (see Belle et al. in Psychol Aging, 18(3):396-405, 2003). Several statistical methodologies are described and their advantages and limitations are explored. Whether weighting the different studies data differently, or via employing random effects, one must recognize that different pooling methodologies may yield different results. Pooling can be used for comprehensive exploratory analyses of data from RCTs and should not be viewed as replacing the standard analysis plan for each study. Pooling may help to identify intervention components that may be more effective especially for subsets of participants with certain behavioral characteristics. Pooling, when supported by statistical tests, can allow exploratory investigation of potential hypotheses and for the design of future interventions.

Protein and Micronutrient Intakes Are Associated with Child Growth and Morbidity from Infancy to Adulthood in the Philippines.

BACKGROUND: Interactions between nutrition and infections in developing countries are complex, and analyses of the interrelations require data from longitudinal studies that span several years and a comprehensive framework facilitating the formulation of food and health policies. OBJECTIVE: The effects of dietary intakes in the Philippines for birth outcomes, heights, weights, and morbidity during ages 2-24 mo; heights and weights during ages 8-19 y; and completed adult heights were analyzed. METHODS: Data on >3000 children from the Cebu Longitudinal Health and Nutrition Survey were modeled in 4 sets of analyses. Cross-sectional and multilevel models were estimated for length and weight at birth. Dynamic random-effects models were estimated for children's heights, weights, and morbidity levels during ages 2-24 mo. Children's heights and weights during ages 8-19 y were modeled by using random-effects models. Children's heights at age 22 y were modeled for investigating the effects of nutritional intakes in early childhood and in adolescence. RESULTS: Maternal anthropometric indicators, energy intakes, and sociodemographic variables were significantly associated with children's length and weight at birth. Dynamic models for children's heights and weights during ages 2-24 mo showed significant effects of calcium and protein intakes; child morbidity levels were significantly associated with height and weight. Higher ß-carotene intakes were significantly associated with lower morbidity levels. Analyses of data on children during ages 8-19 y showed significant effects of protein and calcium intakes and of morbidity levels on heights and weights. Models for children's heights at age 22 y indicated significant effects of protein and calcium intakes during early childhood and in adolescence. CONCLUSIONS: The results underscored the need for formulating long-term food and health policies for the Philippines that enhance children's physical development and ultimately their adult stature, which is important for physical work capacity and labor productivity.

Childhood Obesity Research Demonstration project: cross-site evaluation methods.

INTRODUCTION: The Childhood Obesity Research Demonstration (CORD) project links public health and primary care interventions in three projects described in detail in accompanying articles in this issue of Childhood Obesity. This article describes a comprehensive evaluation plan to determine the extent to which the CORD model is associated with changes in behavior, body weight, BMI, quality of life, and healthcare satisfaction in children 2-12 years of age. DESIGN/METHODS: The CORD Evaluation Center (EC-CORD) will analyze the pooled data from three independent demonstration projects that each integrate public health and primary care childhood obesity interventions. An extensive set of common measures at the family, facility, and community levels were defined by consensus among the CORD projects and EC-CORD. Process evaluation will assess reach, dose delivered, and fidelity of intervention components. Impact evaluation will use a mixed linear models approach to account for heterogeneity among project-site populations and interventions. Sustainability evaluation will assess the potential for replicability, continuation of benefits beyond the funding period, institutionalization of the intervention activities, and community capacity to support ongoing program delivery. Finally, cost analyses will assess how much benefit can potentially be gained per dollar invested in programs based on the CORD model. CONCLUSIONS: The keys to combining and analyzing data across multiple projects include the CORD model framework and common measures for the behavioral and health outcomes along with important covariates at the individual, setting, and community levels. The overall objective of the comprehensive evaluation will develop evidence-based recommendations for replicating and disseminating community-wide, integrated public health and primary care programs based on the CORD model.

Modeling the effects of immunizations timing on child health outcomes in India.

Timely vaccinations of children in developing countries are important for reducing morbidity and mortality, which are Millennium Development Goals. However, a majority of children do not possess vaccination cards compiling information on timing. We investigated the benefits of vaccination cards for the uptake of immunizations against diphtheria, pertussis and tetanus (DPT), polio, tuberculosis (BCG), and measles using data on over 200,000 Indian children from the District Level Health and Facility Survey 3. Methodological issues such as whether parents of children with higher morbidity levels may have them vaccinated were investigated. The results from the models for DPT, polio, measles, and BCG vaccinations showed significant beneficial effects of maternal education, household possessions, and access to health care facilities. Moreover, models for children's ages at the time of vaccination showed significant interactions between maternal education and access to and availability of health care facilities. Finally, models for child morbidity due to diarrhea, cough, and fever showed that timely vaccinations against DPT, access to piped water, and cooking with electricity or natural gas were associated with lower morbidity. Overall, issuing paper or electronic vaccination cards to children is likely to enhance timely uptake of various immunizations thereby reducing child morbidity.

Iron status, malaria parasite loads and food policies: evidence from sub-Saharan Africa.

This brief article investigates the consequences of improving children's iron status for malaria parasite loads by analyzing data from Cote d'Ivoire, Zambia, and Tanzania; the treatment of iron deficiencies has been argued to flare up malaria in under-nourished populations. The data from a randomized controlled trial in Cote d'Ivoire showed statistically insignificant effects of the consumption of iron-fortified biscuits on children's malaria parasite loads. Second, nutrient intakes data from Zambia showed insignificant correlations and associations between children's iron and folate intakes and malaria parasite loads. Third, malaria parasite loads did not change significantly for Tanzanian children receiving anthelmintic treatment; malaria loads were lower for older children and for those using bed nets. Overall, the evidence from sub-Saharan African countries suggests that small improvements in iron status achieved via suitable food policies are unlikely to have detrimental effects for children's malaria parasite loads.

Health care utilization, socioeconomic factors and child health in India.

This paper models the proximate determinants of height, weight and haemoglobin concentration of over 25,000 Indian children using data from the National Family Health Survey-3. The effects of public and private health care service utilization, food consumption patterns and maternal health status on child health were investigated in a multidisciplinary framework. Methodological issues such as potential endogeneity of explanatory variables and the appropriateness of combining height and weight as the body mass index were tackled. The results from models for children's heights and weight showed beneficial effects of child vaccinations against DPT, polio and measles, and negative effects of not utilizing government health facilities. The models for children's haemoglobin concentration indicated beneficial effects of food consumption patterns and treatment against intestinal parasites. The results provide several insights for improving child health in India.

Modeling the effects of physician emigration on human development.

We analyzed the effects of physician emigration on human development indicators in developing countries. First, the geographical distribution of physician brain drain was documented for the period 1991-2004. Second, random and fixed effects models were employed to investigate the effects of physicians in the home countries and abroad on child mortality and vaccination rates. Third, models were estimated to investigate migration-induced incentives in the medical sector that would increase the number of physicians. The results showed positive effects of migration prospects on medical training though the magnitude was too small for generating a net brain gain. Also, infant and child mortality rates were negatively associated with the number of physicians per capita after adult literacy rates exceeded 60%. The results for DPT and measles vaccinations underscored the importance of literacy rates and physicians per capita for higher vaccination rates. From the standpoint of Millennium Development Goals, reducing medical brain drain is likely to have only small benefits for child mortality and vaccination rates.

Healthcare infrastructure and emotional support are predictors of CD4 cell counts and quality of life indices of patients on antiretroviral treatment in Free State Province, South Africa.

While many AIDS patients in sub-Saharan Africa are receiving antiretroviral treatment (ART) via public clinics, improvements in health status also depend on socioeconomic and psychological factors and quality of healthcare services. Inter-dependence between patients' clinical markers and quality of life indicators should be analyzed using comprehensive models. This longitudinal study compiled socioeconomic and clinical variables at six monthly intervals on patients receiving ART in South Africa; patients' ratings of quality of services and staff in "Assessment" and "Treatment" sites were assessed. Dynamic random effects models were estimated by maximum likelihood for CD4 cell counts and for quality of life indices (EQ-5D and Visual Analogue Scale), incorporating the inter-dependence between plasma HIV RNA levels and CD4 cell counts. The results showed that emotional support received by patients was a significant predictor (P<0.05) of CD4 cell counts and quality of life indices. Ratings of services and staff in Assessment and Treatment sites were significantly associated with CD4 cell counts and quality of life indices; CD4 cell count was a significant predictor of quality of life indices. The results indicated that it is important to compile socioeconomic and psychological variables for AIDS patients and monitor healthcare services for improving their health status and quality of life.

Randomized controlled experiments in health and social sciences: some conceptual issues.

This brief article outlines some difficulties as well as benefits in conducting randomized controlled trials in social science settings especially in developing countries. Some of the historical developments are summarized and certain applications in health sciences are discussed from methodological and policy standpoints.

Socio-economic, behavioural and environmental factors predicted body weights and household food insecurity scores in the Early Childhood Longitudinal Study-Kindergarten.

Recent increases in obesity prevalence among children in developed countries are of policy concern. While significant positive associations between households' food insecurity status and body weights have been reported for adults, it is known from the energy physiology literature that energy requirements depend on BMR, anthropometric measures and physical activity. It is therefore important to model the bi-directional relationships between body weights and households' food insecurity scores especially for children that have evolving nutrient and energy requirements. The present paper estimated dynamic random effects models for children's body weights and BMI, and households' food insecurity scores using longitudinal data on 7635 children in the USA enrolled in 1st, 3rd and 5th grades (1999-2003) of the Early Childhood Longitudinal Study-Kindergarten. The main findings were, first, physical exercise and numbers of siblings were significantly (P < 0.05) negatively associated with body weights, while households' food insecurity score was not a significant predictor. Moreover, children's body weights were significantly lower in households with higher parental education and incomes; time spent watching television and in non-parental care were positively associated with weights. Second, models for households' food insecurity scores showed that poverty and respondents' poor emotional and physical health significantly increased food insecurity. Moreover, households with children who were taller and heavier for their ages faced significantly higher food insecurity levels. Overall, the results showed that household food insecurity was unlikely to exacerbate child obesity in the USA and it is important that children receive balanced school meals and perform higher physical activity.