Multilevel Analysis in Household Survey: An Application to Health Condition Data

The aim of this thesis is to apply multilevel regression model in context of household surveys. Hierarchical structure in this type of data is characterized by many small groups. In last years comparative and multilevel analysis in the field of perceived health have grown in size. The purpose of this thesis is to develop a multilevel analysis with three level of hierarchy for Physical Component Summary outcome to: evaluate magnitude of within and between variance at each level (individual, household and municipality); explore which covariates affect on perceived physical health at each level; compare model-based and design-based approach in order to establish informativeness of sampling design; estimate a quantile regression for hierarchical data. The target population are the Italian residents aged 18 years and older. Our study shows a high degree of homogeneity within level 1 units belonging from the same group, with an intraclass correlation of 27% in a level-2 null model. Almost all variance is explained by level 1 covariates. In fact, in our model the explanatory variables having more impact on the outcome are disability, unable to work, age and chronic diseases (18 pathologies). An additional analysis are performed by using novel procedure of analysis :"Linear Quantile Mixed Model", named "Multilevel Linear Quantile Regression", estimate. This give us the possibility to describe more generally the conditional distribution of the response through the estimation of its quantiles, while accounting for the dependence among the observations. This has represented a great advantage of our models with respect to classic multilevel regression. The median regression with random effects reveals to be more efficient than the mean regression in representation of the outcome central tendency. A more detailed analysis of the conditional distribution of the response on other quantiles highlighted a differential effect of some covariate along the distribution.

Predictors of vaginal practices for sex and hygiene in KwaZulu-Natal, South Africa: findings of a household survey and qualitative inquiry

Vaginal practices in sub-Saharan Africa may increase HIV transmission and have important implications for development of microbicides and future HIV prevention technologies. It remains unclear which women undertake vaginal practices and what factors predict prevalence, practice type and choice of products. Using cross-sectional data from mixed research methods, we identify factors associated with vaginal practices among women in KwaZulu-Natal, South Africa. Data were gathered through focus group discussions, in-depth and key-informant interviews, followed by a province-wide, multi-stage cluster household survey, using structured questionnaires in face-to-face interviews with 867 women. This paper details six types of vaginal practices, which--despite their individual distinctiveness and diverse motivations--may be clustered into two broad groups: those undertaken for purposes of 'hygiene' (genital washing, douching and application) and those for 'sexual motivations' (application, insertion, ingestion and incisions). Multivariate analysis found significant associations between 'hygiene' practices and media access, religiosity and transactional sex. 'Sexual' practices were associated with partner concurrency, religiosity and use of injectable hormonal contraceptives. Future interventions relating to vaginal practices as well as microbicides need to reflect this characterisation of practices as sexual- and/or hygiene-related.

Prevalence, motivations, and adverse effects of vaginal practices in Africa and Asia: findings from a multicountry household survey

Background: Women worldwide use various vaginal practices to clean or modify their vulva and vagina. Additional population-level information is needed on prevalence and motivations for these practices, characteristics of users, and their adverse effects. Methods: This was a household survey using multistage cluster sampling in Tete, Mozambique; KwaZulu-Natal, South Africa; Yogyakarta, Indonesia; and Chonburi, Thailand. In 2006–2007, vaginal practices and their motivations were examined using structured interviews with women 18–60 years of age (n=3610). Results: Prevalence, frequency, and motivations varied markedly. Two thirds of women in Yogyakarta and Chonburi reported one or more practices. In Yogyakarta, nearly half ingest substances with vaginal effects, and in Chonburi, external washing and application predominate. In Tete, half reported three or four current practices, and a quarter reported five or more practices. Labial elongation was near universal, and 92% of those surveyed cleanse internally. Two third's in KwaZulu-Natal practiced internal cleansing. Insertion of traditional solid products was rare in Chonburi and Yogyakarta, but one tenth of women in KwaZulu-Natal and nearly two thirds of women in Tete do so. Multivariate analysis of the most common practice in each site showed these were more common among less educated women in Africa and young urban women in Asia. Explicit sexual motivations were frequent in KwaZulu-Natal and Tete, intended for pleasure and maintaining partner commitment. Practices in Chonburi and Yogyakarta were largely motivated by femininity and health. Genital irritation was common at African sites. Conclusions: Vaginal practices are not as rare, exotic, or benign as sometimes assumed. Limited evidence of their biomedical consequences remains a concern; further investigation of their safety and sexual health implications is warranted.

Transmission dynamics of extended-spectrum β-lactamase-producing Enterobacteriaceae in the tertiary care hospital and the household setting

Studies about transmission rates of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in hospitals and households are scarce.

Human and embodied energy analysis applied to water source protection and household water treatment interventions used in Mali, West Africa

As water quality interventions are scaled up to meet the Millennium Development Goal of halving the proportion of the population without access to safe drinking water by 2015 there has been much discussion on the merits of household- and source-level interventions. This study furthers the discussion by examining specific interventions through the use of embodied human and material energy. Embodied energy quantifies the total energy required to produce and use an intervention, including all upstream energy transactions. This model uses material quantities and prices to calculate embodied energy using national economic input/output-based models from China, the United States and Mali. Embodied energy is a measure of aggregate environmental impacts of the interventions. Human energy quantifies the caloric expenditure associated with the installation and operation of an intervention is calculated using the physical activity ratios (PARs) and basal metabolic rates (BMRs). Human energy is a measure of aggregate social impacts of an intervention. A total of four household treatment interventions – biosand filtration, chlorination, ceramic filtration and boiling – and four water source-level interventions – an improved well, a rope pump, a hand pump and a solar pump – are evaluated in the context of Mali, West Africa. Source-level interventions slightly out-perform household-level interventions in terms of having less total embodied energy. Human energy, typically assumed to be a negligible portion of total embodied energy, is shown to be significant to all eight interventions, and contributing over half of total embodied energy in four of the interventions. Traditional gender roles in Mali dictate the types of work performed by men and women. When the human energy is disaggregated by gender, it is seen that women perform over 99% of the work associated with seven of the eight interventions. This has profound implications for gender equality in the context of water quality interventions, and may justify investment in interventions that reduce human energy burdens.

The impact of balsamo (Myroxylon balsamum L. Harms) on coffee yield and household income in El Balsamar, El Salvador

El Balsamar is a community that relies upon coffee trees intercropped with the balsamo tree (Myroxylon balsamum L. Harms) for a substantial portion of household income. The balsamo tree is valued for its resin which is used as medicine in the community and sold commercially. Farmers believe that the shade from the balsamo tree decreases coffee yield compared to the shade from non balsamo species. Thirty coffee farms were studied, each set up as a paired plot. When cover type was balsamo, coffee yield was more likely to decrease. Plots with higher basal area were more likely to be balsamo cover type. As basal area increased, coffee yield decreased. Although coffee yield is lower under balsamo cover type, farmers still continue to plant and manage coffee under this cover type. Farmers accept a lower coffee yield because balsamo resin provides an important income source. Farmers rely on the community cooperative to provide them work to support their households. The cooperative relies on the farmers to provide the labor needed to harvest coffee and extract balsamo resin.

HOUSEHOLD SOLAR POWER SYSTEM

Photovoltaic power has become one of the most popular research area in new energy field. In this report, the case of household solar power system is presented. Based on the Matlab environment, the simulation is built by using Simulink and SimPowerSystem. There are four parts in a household solar system, solar cell, MPPT system, battery and power consumer. Solar cell and MPPT system are been studied and analyzed individually. The system with MPPT generates 30% more energy than the system without MPPT. After simulating the household system, it is can be seen that the power which generated by the system is 40.392 kWh per sunny day. By combining the power generated by the system and the price of the electric power, 8.42 years are need for the system to achieve a balance of income and expenditure when weather condition is considered.

Household Hardships, Public Programs, and Their Associations with the Health and Development of Very Young Children: Insights from Children’s HealthWatch

America’s low-income families struggle to protect their children from multiple threats to their health and growth. Many research and advocacy groups explore the health and educational effects of food insecurity, but less is known about these effects on very young children. Children’s HealthWatch, a group of pediatric clinicians and public health researchers, has continuously collected data on the effects of food insecurity alone and in conjunction with other household hardships since 1998. The group’s peer reviewed research has shown that a number of economic risks at the household level, including food, housing and energy insecurity, tend to be correlated. These insecurities alone or in conjunction increase the risk that a young child will suffer various negative health consequences, including increases in lifetime hospitalizations, parental report of fair or poor health,1 or risk for developmental delays.2 Child food insecurity is an incremental risk indicator above and beyond the risk imposed by household-level food insecurity. The Children’sHealthwatch research also suggests public benefits programs modify some of these effects for families experiencing hardships. This empirical evidence is presented in a variety of public venues outside the usual scientific settings, such as congressional hearings, to support the needs of America’s most vulnerable population through policy change. Children’s HealthWatch research supports legislative solutions to food insecurity, including sustained funding for public programs and re-evaluation of the use of the Thrifty Food Plan as the basis of SNAP benefits calculations. Children’s HealthWatch is one of many models to support the American Academy of Pediatrics’ call to “stand up, speak up, and step up for children.”3 No isolated group or single intervention will solve child poverty or multiple hardships. However, working collaboratively each group has a role to play in supporting the health and well-being of young children and their families. 1. Cook JT, Frank DA, Berkowitz C, et al. Food insecurity is associated with adverse health outcomes among human infants and toddlers. J Nutr. 2004;134:1432-1438. 2. Rose-Jacobs R, Black MM, Casey PH, et al. Household food insecurity: associations with at-risk infant and toddler development. Pediatrics. 2008;121:65-72. 3. AAP leader says to stand up, speak up, and step up for child health [news release]. Boston, MA: American Academy of Pediatrics; October 11, 2008. http://www2.aap.org/pressroom/nce/nce08childhealth.htm. Accessed January 1, 2012.

Commentary on "Household Hardships, Public Programs, and Their Associations with the Health and Development of Very Young Children: Insights from Children's HealthWatch"

This commentary, written in response to the article "Household Hardships, Public Programs, and Their Associations with the Health and Development of Very Young Children: Insights from Children's HealthWatch", highlights the importance of the research done by Children's HealthWatch in relation to childhood food insecurity. Childhood food insecurity has been linked with various adverse health effects, including undernutrition, poor or delayed child development, and social and psychological consequences. Children's HealthWatch provides important data that can be used to monitor threats to our children's well-being and address problems with effective interventions.

Protect Children From Household Food Insecurity: Promote Access To Food and Stress-Alleviating Resources

Household food insecurity is associated with threats to children’s intellectual, behavioral, and psycho-emotional development. In addition to poor food quality and quantity, the stress associated with food insecurity can undermine caregiver mental health and family functioning. Evidence demonstrates that national assistance programs and policies are needed to ensure that families and children have access to adequate sources of healthy food and to stress-alleviating resources.

Commentary on "Exploring the Association Between Household Food Insecurity, Parental Self-Efficacy and Fruit and Vegetable Parenting Practices Among Parents of 5- to 8-Year-Old Overweight Children"

Invited commentary of an article that discusses the association between parental factors and food insecurity by Angela Hilmers, Karen Cullen, Carolyn Moore and Teresia O’Connor.

Exploring the Association Between Household Food Insecurity, Parental Self-Efficacy, and Fruit and Vegetable Parenting Practices Among Parents of 5- to 8-Year-Old Overweight Children

Background: Food insecurity may negatively impact children’s nutritional status by affecting parenting quality. Because parents have a strong influence on their children’s eating and food choices, examining the effects of food insecurity on parenting may provide important insights into obesity prevention efforts. Objectives: This study explored whether food insecurity was associated with parental self-efficacy and parenting practices related to fruit and vegetable consumption. Methods: Secondary analysis was performed using baseline data from 31 mothers of 5-8 year old overweight or obese children who had participated in a pilot obesity treatment program. Household food security status, fruit and vegetable parental self-efficacy (modeling/socialization, planning/encouraging and availability/accessibility) and fruit and vegetable parenting practices (structure, responsiveness, non-directive control, and external control) were assessed using validated measures. Students' t-test investigated differences in subscales by food security status. Results: There were no significant differences in fruit and vegetable parenting practices and parental self-efficacy between food secure and insecure groups. There was a trend towards a decrease in parental self-efficacy for making fruit and vegetables available in the home among food insecure parents (p=.06). Conclusions: In this small sample no significant associations were found between food insecurity and fruit and vegetable parenting practices and parental self-efficacy. However, the trend observed in this exploratory analysis supports further hypothesis-driven research with a larger sample size able to detect more subtle differences.