Demographic, socio-economic, obstetric, and behavioral factors associated with small-and large-for-gestational-age from a prospective, population-based pregnancy cohort in rural Nepal: a secondary data analysis.

BACKGROUND: In South Asia, a third of babies are born small-for-gestational age (SGA). The risk factors are well described in the literature, but many studies are in high-and-middle income countries or measure SGA on facility births only. There are fewer studies that describe the prevalence of risk factors for large-for-gestational age (LGA) in low-income countries. We aim to describe the factors associated with SGA and LGA in a population-based cohort of pregnant women in rural Nepal. METHODS: This is a secondary data analysis of community-based trial on neonatal oil massage (22,545 women contributing 39,479 pregnancies). Demographic, socio-economic status (SES), medical/obstetric history, and timing of last menstruation were collected at enrollment. Vital signs, illness symptoms, and antenatal care (ANC) attendance were collected throughout the pregnancy and neonatal weight was measured for live births. We conducted multivariate analysis using multinomial, multilevel logistic regression, reporting the odds ratio (OR) with 95% confidence intervals (CIs). Outcomes were SGA, LGA compared to appropriate-for-gestational age (AGA) and were multiply imputed using birthweight recalibrated to time at delivery. RESULTS: SGA was associated with nulligravida (OR: 2.12 95% CI: 1.93-2.34), gravida/nulliparous (OR: 1.86, 95% CI: 1.26-2.74), interpregnancy intervals less than 18 months (OR: 1.16, 95% CI: 1.07-1.27), and poor appetite/vomiting in the second trimester, (OR: 1.27, 95% CI: 1.19-1.35). Greater wealth (OR: 0.78, 95% CI: 0.69-0.88), swelling of hands/face in the third trimester (OR: 0.81, 95% CI: 0.69-0.94) parity greater than five (OR: 0.77, 95% CI: 0.65-0.92), male fetal sex (OR: 0.91, 95% CI: 0.86-0.98), and increased weight gain (OR: 0.93 per weight kilogram difference between 2nd and 3rd trimester, 95% CI: 0.92-0.95) were protective for SGA. Four or more ANC visits (OR: 0.53, 95% CI: 0.41-0.68) and respiratory symptoms in the third trimester (OR: 0.67, 95% CI: 0.54-0.84) were negatively associated with LGA, and maternal age < 18 years (OR: 1.39, 95% CI: 1.03-1.87) and respiratory symptoms in the second trimester (OR: 1.27, 95% CI: 1.07-1.51) were positively associated with LGA. CONCLUSIONS: Our findings are in line with known risk factors for SGA. Because the prevalence and mortality risk of LGA babies is low in this population, it is likely LGA status does not indicate underlaying illness. Improved and equitable access to high quality antenatal care, monitoring for appropriate gestational weight gain and increased monitoring of women with high-risk pregnancies may reduce prevalence and improve outcomes of SGA babies. TRIAL REGISTRATION: The study used in this secondary data analysis was registered at Clinicaltrials.gov NCT01177111.

Development of an imputation model to recalibrate birth weights measured in the early neonatal period to time at delivery and assessment of its impact on size-for-gestational age and low birthweight prevalence estimates: a secondary analysis of a pregnancy cohort in rural Nepal.

OBJECTIVES: In low-income countries, birth weights for home deliveries are often measured at the nadir when babies may lose up of 10% of their birth weight, biasing estimates of small-for-gestational age (SGA) and low birth weight (LBW). We aimed to develop an imputation model that predicts the 'true' birth weight at time of delivery. DESIGN: We developed and applied a model that recalibrates weights measured in the early neonatal period to time=0 at delivery and uses those recalibrated birth weights to impute missing birth weights. SETTING: This is a secondary analysis of pregnancy cohort data from two studies in Sarlahi district, Nepal. PARTICIPANTS: The participants are 457 babies with daily weights measured in the first 10 days of life from a subsample of a larger clinical trial on chlorhexidine (CHX) neonatal skin cleansing and 31 116 babies followed through the neonatal period to test the impact of neonatal massage oil type (Nepal Oil Massage Study (NOMS)). OUTCOME MEASURES: We developed an empirical Bayes model of early neonatal weight change using CHX trial longitudinal data and applied it to the NOMS dataset to recalibrate and then impute birth weight at delivery. The outcomes are size-for-gestational age and LBW. RESULTS: When using the imputed birth weights, the proportion of SGA is reduced from 49% (95% CI: 48% to 49%) to 44% (95% CI: 43% to 44%). Low birth weight is reduced from 30% (95% CI: 30% to 31%) to 27% (95% CI: 26% to 27%). The proportion of babies born large-for-gestational age increased from 4% (95% CI: 4% to 4%) to 5% (95% CI: 5% to 5%). CONCLUSIONS: Using weights measured around the nadir overestimates the prevalence of SGA and LBW. Studies in low-income settings with high levels of home births should consider a similar recalibration and imputation model to generate more accurate population estimates of small and vulnerable newborns.

Assessment of indirect protection from maternal influenza immunization among non-vaccinated household family members in a randomized controlled trial in Sarlahi, Nepal.

Influenza is a significant cause of morbidity and mortality worldwide, and the World Health Organization highly recommends maternal vaccination during pregnancy. The indirect effect of maternal vaccination on other close contacts other than newborns is unknown. To evaluate this, we conducted a nested substudy between 2011 and 2012 of influenza and acute respiratory illness (ARI) among household members of pregnant women enrolled in a randomized placebo-controlled trial of antenatal influenza vaccination in the rural district of Sarlahi, Nepal. Women were assigned to receive influenza vaccination or placebo during pregnancy and then they and their household members were followed up to 6 months postpartum with weekly symptom surveillance and nasal swab collection. Swabs were tested by RT-PCR for influenza. Rates of laboratory-confirmed influenza and of ARI were compared between vaccine and placebo groups using generalized estimating equations with a Poisson link function. Overall, 1752 individuals in 520 households were eligible for inclusion. There were 82 laboratory-confirmed influenza illness episodes, for a rate of 7.0 per 100 person-years overall. Of the influenza strains able to be typed, 29 were influenza A, 40 were influenza B, and 6 were coinfections with influenza A and B. The rate did not differ significantly whether the household was in the vaccine or placebo group (rate ratio (RR) 1.37, 95% confidence interval (CI) 0.83-2.26). The rate of ARI was 28.5 per 100 person-years overall and did not differ by household group (RR 0.99, 95% CI 0.72-1.36). Influenza vaccination of pregnant women did not provide indirect protection of unvaccinated household members.

Measuring wealth in rural communities: Lessons from the Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial.

BACKGROUND: Poverty and human capital development are inextricably linked and therefore research on human capital typically incorporates measures of economic well-being. In the context of randomized trials of health interventions, for example, such measures are used to: 1) assess baseline balance; 2) estimate covariate-adjusted analyses; and 3) conduct subgroup analyses. Many factors characterize economic well-being, however, and analysts often generate summary measures such as indices of household socio-economic status or wealth. In this paper, a household wealth index is developed and tested for participants in the cluster-randomized Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe. METHODS: Building on the approach used in the Zimbabwe Demographic and Health Survey (ZDHS), we combined a set of housing characteristics, ownership of assets and agricultural resources into a wealth index using principal component analysis (PCA) on binary variables. The index was assessed for internal and external validity. Its sensitivity was examined considering an expanded set of variables and an alternative statistical approach of polychoric PCA. Correlation between indices was determined using the Spearman's rank correlation coefficient and agreement between quintiles using a linear weighted Kappa statistic. Using the 2015 ZDHS data, we constructed a separate index and applied the loadings resulting from that analysis to the SHINE study population, to compare the wealth distribution in the SHINE study with rural Zimbabwe. RESULTS: The derived indices using the different methods were highly correlated (r>0.9), and the wealth quintiles derived from the different indices had substantial to near perfect agreement (linear weighted Kappa>0.7). The indices were strongly associated with a range of assets and other wealth measures, indicating both internal and external validity. Households in SHINE were modestly wealthier than the overall population of households in rural Zimbabwe. CONCLUSION: The SHINE wealth index developed here is a valid and robust measure of wealth in the sample.

Burden and Risk Factors for Coronavirus Infections in Infants in Rural Nepal.

Background: Knowledge of risk factors for symptomatic human coronavirus (HCoV) infections in children in community settings is limited. We estimated the disease burden and impact of birth-related, maternal, household, and seasonal factors on HCoV infections among children from birth to 6 months old in rural Nepal. Methods: Prospective, active, weekly surveillance for acute respiratory infections (ARIs) was conducted in infants over a period of 3 years during 2 consecutive, population-based randomized trials of maternal influenza immunization. Midnasal swabs were collected for acute respiratory symptoms and tested for HCoV and other viruses by reverse-transcription polymerase chain reaction. Association between HCoV incidence and potential risk factors was modeled using Poisson regression. Results: Overall, 282 of 3505 (8%) infants experienced an HCoV ARI within the first 6 months of life. HCoV incidence overall was 255.6 (95% confidence interval [CI], 227.3-286.5) per 1000 person-years, and was more than twice as high among nonneonates than among neonates (incidence rate ratio [IRR], 2.53; 95% CI, 1.52-4.21). HCoV ARI incidence was also positively associated with the number of children <5 years of age per room in a household (IRR, 1.13; 95% CI, 1.01-1.28). Of the 296 HCoV infections detected, 46% were coinfections with other respiratory viruses. While HCoVs were detected throughout the study period, seasonal variation was also observed, with incidence peaking in 2 winters (December-February) and 1 autumn (September-November). Conclusions: HCoV is associated with a substantial proportion of illnesses among young infants in rural Nepal. There is an increased risk of HCoV infection beyond the first month of life.

Estimates of burden and consequences of infants born small for gestational age in low and middle income countries with INTERGROWTH-21st standard: analysis of CHERG datasets.

Objectives To estimate small for gestational age birth prevalence and attributable neonatal mortality in low and middle income countries with the INTERGROWTH-21st birth weight standard.Design Secondary analysis of data from the Child Health Epidemiology Reference Group (CHERG), including 14 birth cohorts with gestational age, birth weight, and neonatal follow-up. Small for gestational age was defined as infants weighing less than the 10th centile birth weight for gestational age and sex with the multiethnic, INTERGROWTH-21st birth weight standard. Prevalence of small for gestational age and neonatal mortality risk ratios were calculated and pooled among these datasets at the regional level. With available national level data, prevalence of small for gestational age and population attributable fractions of neonatal mortality attributable to small for gestational age were estimated.Setting CHERG birth cohorts from 14 population based sites in low and middle income countries.Main outcome measures In low and middle income countries in the year 2012, the number and proportion of infants born small for gestational age; number and proportion of neonatal deaths attributable to small for gestational age; the number and proportion of neonatal deaths that could be prevented by reducing the prevalence of small for gestational age to 10%.Results In 2012, an estimated 23.3 million infants (uncertainty range 17.6 to 31.9; 19.3% of live births) were born small for gestational age in low and middle income countries. Among these, 11.2 million (0.8 to 15.8) were term and not low birth weight (≥2500 g), 10.7 million (7.6 to 15.0) were term and low birth weight (<2500 g) and 1.5 million (0.9 to 2.6) were preterm. In low and middle income countries, an estimated 606 500 (495 000 to 773 000) neonatal deaths were attributable to infants born small for gestational age, 21.9% of all neonatal deaths. The largest burden was in South Asia, where the prevalence was the highest (34%); about 26% of neonatal deaths were attributable to infants born small for gestational age. Reduction of the prevalence of small for gestational age from 19.3% to 10.0% in these countries could reduce neonatal deaths by 9.2% (254 600 neonatal deaths; 164 800 to 449 700).Conclusions In low and middle income countries, about one in five infants are born small for gestational age, and one in four neonatal deaths are among such infants. Increased efforts are required to improve the quality of care for and survival of these high risk infants in low and middle income countries.

Community survey on awareness and use of obstetric ultrasonography in rural Sarlahi District, Nepal.

OBJECTIVE: To assess levels of awareness and use of obstetric ultrasonography in rural Nepal. METHODS: Between March 2014 and March 2015, a cross-sectional survey was conducted among married women aged 15-40years residing in rural Sarlahi District, Nepal, regarding their knowledge and use of obstetric ultrasonography during their most recent pregnancy. Regression analyses were conducted to identify reproductive health, socioeconomic, and other characteristics that increased the likelihood of undergoing an obstetric ultrasonographic examination. RESULTS: Among 6182 women, 1630 (26.4%) had undergone obstetric ultrasonography during their most recent pregnancy, of whom 1011 (62.0%) received only one examination. Odds of receiving an ultrasonographic examination were higher among women with post-secondary education than among those with none (≥11years' education: adjusted odds ratio [aOR] 10.28, 95% confidence interval [CI] 5.55-19.04), and among women whose husbands had post-secondary education than among those with husbands with none (≥11years' education: aOR 1.99, 95% CI 1.47-2.69). Odds were lower among women younger than 18years than among those aged 18-34years (aOR 0.72, 95% confidence interval 0.59-0.90). CONCLUSION: Utilization of obstetric ultrasonography in rural Nepal was very limited. Further research is necessary to assess the potential health impact of obstetric ultrasonography in low-resource settings, while addressing limitations such as cost and misuse.

Low correlation between household carbon monoxide and particulate matter concentrations from biomass-related pollution in three resource-poor settings.

Household air pollution from the burning of biomass fuels is recognized as the third greatest contributor to the global burden of disease. Incomplete combustion of biomass fuels releases a complex mixture of carbon monoxide (CO), particulate matter (PM) and other toxins into the household environment. Some investigators have used indoor CO concentrations as a reliable surrogate of indoor PM concentrations; however, the assumption that indoor CO concentration is a reasonable proxy of indoor PM concentration has been a subject of controversy. We sought to describe the relationship between indoor PM2.5 and CO concentrations in 128 households across three resource-poor settings in Peru, Nepal, and Kenya. We simultaneously collected minute-to-minute PM2.5 and CO concentrations within a meter of the open-fire stove for approximately 24h using the EasyLog-USB-CO data logger (Lascar Electronics, Erie, PA) and the personal DataRAM-1000AN (Thermo Fisher Scientific Inc., Waltham, MA), respectively. We also collected information regarding household construction characteristics, and cooking practices of the primary cook. Average 24h indoor PM2.5 and CO concentrations ranged between 615 and 1440 µg/m(3), and between 9.1 and 35.1 ppm, respectively. Minute-to-minute indoor PM2.5 concentrations were in a safe range (<25 µg/m(3)) between 17% and 65% of the time, and exceeded 1000 µg/m(3) between 8% and 21% of the time, whereas indoor CO concentrations were in a safe range (<7 ppm) between 46% and 79% of the time and exceeded 50 ppm between 4%, and 20% of the time. Overall correlations between indoor PM2.5 and CO concentrations were low to moderate (Spearman ρ between 0.59 and 0.83). There was also poor agreement and evidence of proportional bias between observed indoor PM2.5 concentrations vs. those estimated based on indoor CO concentrations, with greater discordance at lower concentrations. Our analysis does not support the notion that indoor CO concentration is a surrogate marker for indoor PM2.5 concentration across all settings. Both are important markers of household air pollution with different health and environmental implications and should therefore be independently measured.

Feasibility intervention trial of two types of improved cookstoves in three resource-limited settings: study protocol for a randomized controlled trial.

BACKGROUND: Exposure to biomass fuel smoke is one of the leading risk factors for disease burden worldwide. International campaigns are currently promoting the widespread adoption of improved cookstoves in resource-limited settings, yet little is known about the cultural and social barriers to successful improved cookstove adoption and how these barriers affect environmental exposures and health outcomes. DESIGN: We plan to conduct a one-year crossover, feasibility intervention trial in three resource-limited settings (Kenya, Nepal and Peru). We will enroll 40 to 46 female primary cooks aged 20 to 49 years in each site (total 120 to 138). METHODS: At baseline, we will collect information on sociodemographic characteristics and cooking practices, and measure respiratory health and blood pressure for all participating women. An initial observational period of four months while households use their traditional, open-fire design cookstoves will take place prior to randomization. All participants will then be randomized to receive one of two types of improved, ventilated cookstoves with a chimney: a commercially-constructed cookstove (Envirofit G3300/G3355) or a locally-constructed cookstove. After four months of observation, participants will crossover and receive the other improved cookstove design and be followed for another four months. During each of the three four-month study periods, we will collect monthly information on self-reported respiratory symptoms, cooking practices, compliance with cookstove use (intervention periods only), and measure peak expiratory flow, forced expiratory volume at 1 second, exhaled carbon monoxide and blood pressure. We will also measure pulmonary function testing in the women participants and 24-hour kitchen particulate matter and carbon monoxide levels at least once per period. DISCUSSION: Findings from this study will help us better understand the behavioral, biological, and environmental changes that occur with a cookstove intervention. If this trial indicates that reducing indoor air pollution is feasible and effective in resource-limited settings like Peru, Kenya and Nepal, trials and programs to modify the open burning of biomass fuels by installation of low-cost ventilated cookstoves could significantly reduce the burden of illness and death worldwide. TRIAL REGISTRATION: ClinicalTrials.gov NCT01686867.

Household wealth and neurocognitive development disparities among school-aged children in Nepal.

BACKGROUND: Wealth disparities in child developmental outcomes are well documented in developed countries. We sought to (1) describe the extent of wealth-based neurocognitive development disparities and (2) examine potential mediating factors of disparities among a population-based cohort of children in rural Nepal. METHODS: We investigated household wealth-based differences in intellectual, executive and motor function of n = 1692 children aged between 7 and 9 years in Nepal. Using linear mixed models, wealth-based differences were estimated before and after controlling for child and household demographic characteristics. We further examined wealth-based differences adjusted for three sets of mediators: child nutritional status, home environment, and schooling pattern. RESULTS: We observed a positive gradient in child neurocognitive performance by household wealth. After adjusting for child and household control factors, disparities between children in the highest and lowest wealth quintiles persisted in intellectual and motor function, but not executive function. No statistically significant wealth-based differentials in outcomes remained after accounting for nutritional status, home environment, and schooling patterns. The largest differences in neurocognitive development were associated with schooling pattern. CONCLUSIONS: Household wealth patterns child neurocognitive development in rural Nepal, likely through its influence on nutritional status, the home environment, and schooling. In the current context, improving early and regular schooling in this setting is critical to addressing wealth-based disparities in outcomes.

Sex differences in neonatal mortality in Sarlahi, Nepal: the role of biology and environment.

BACKGROUND: Studies in South Asia have documented increased risk of neonatal mortality among girls, despite evidence of a biological survival advantage. Associations between gender preference and mortality are cited as reasons for excess mortality among girls. This has not, however, been tested in statistical models. METHODS: A secondary analysis of data from a population-based randomised controlled trial of newborn infection prevention conducted in rural southern Nepal was used to estimate sex differences in early and late neonatal mortality, with girls as the reference group. The analysis investigated which underlying biological factors (immutable factors specific to the newborn or his/her mother) and environmental factors (mutable external factors) might explain observed sex differences in mortality. RESULTS: Neonatal mortality was comparable by sex (Ref=girls; OR 1.06, 95% CI 0.92 to 1.22). When stratified by neonatal period, boys were at 20% (OR 1.20, 95% CI 1.02% to 1.42%) greater risk of early and girls at 43% (OR 0.70, 95% CI 0.51% to 0.94%) greater risk of late neonatal mortality. Biological factors, primarily respiratory depression and unconsciousness at birth, explained excess early neonatal mortality among boys. Increased late neonatal mortality among girls was explained by a three-way environmental interaction between ethnicity, sex and prior sibling composition (categorised as primiparous newborns, infants born to families with prior living boys or boys and girls, and infants born to families with only prior living girls). CONCLUSIONS: Risk of neonatal mortality inverted between the early and late neonatal periods. Excess risk of early neonatal death among boys was consistent with biological expectations. Excess risk for late neonatal death among girls was not explained by overarching gender preference or preferential care-seeking for boys as hypothesised, but was driven by increased risk among Madeshi girls born to families with only prior girls.

Cataract surgery among Medicare beneficiaries.

PURPOSE: To present descriptive epidemiology of cataract surgery among Medicare recipients in the United States. SETTING: Cataract surgery performed on Medicare beneficiaries in 2003 and 2004. METHODS: Medicare claims data were used to identify all cataract surgery claims for procedures performed in the United States in 2003-2004. Standard assumptions were used to limit the claims to actual cataract surgery procedures performed. Summary statistics were created to determine the number of procedures performed for each outcome of interest: cataract surgery rates by age, sex, race and state; surgical volume by facility type and surgeon characteristics; time interval between first- and second-eye cataract surgery. RESULTS: The national cataract surgery rate for 2003-2004 was 61.8 per 1000 Medicare beneficiary person-years. The rate was significantly higher for females and for those aged 75-84 years. After adjustment for age and sex, blacks had approximately a 30% lower rate of surgery than whites. While only 5% of cataract surgeons performed more than 500 cataract surgeries annually, these surgeons performed 26% of the total cataract surgeries. Increasing surgical volume was found to be highly correlated with use of ambulatory surgical centers and reduced time interval between first- and second-eye surgery in the same patient. CONCLUSIONS: The epidemiology of cataract surgery in the United States Medicare population documents substantial variation in surgical rates by race, sex, age, and by certain provider characteristics.

Postcataract surgery endophthalmitis in the United States: analysis of the complete 2003 to 2004 Medicare database of cataract surgeries.

OBJECTIVE: To estimate endophthalmitis incidence after cataract surgery nationally and at the state level in 2003 and 2004 and to explore risk factors. DESIGN: Analysis of Medicare beneficiary claims data. PARTICIPANTS: We evaluated billed claims for cataract surgery and endophthalmitis diagnosis and treatment for all Medicare fee-for-service beneficiaries in 2003-2004. METHODS: Cataract surgeries were identified by procedure codes and merged with demographic information. Cataract annual surgical volume was calculated for all surgeons. Presumed postoperative endophthalmitis cases were identified by International Classification of Diseases-9 Clinical Modification Codes on claims within 42 days after surgery. Endophthalmitis rates and 95% confidence intervals (CI) were calculated at state and national levels. Logistic regression was used to investigate the association between developing endophthalmitis and surgery location and surgeon factors. MAIN OUTCOME MEASURES: Endophthalmitis incidence and risk factors. RESULTS: We included 4006 cases of presumed endophthalmitis, which occurred after 3 280 966 cataract surgeries. The national rate in 2003 was 1.33 per 1000 surgeries (95% CI, 1.27-1.38) and decreased to 1.11 per 1000 (95% CI, 1.06-1.16) in 2004. Males (relative risk [RR], 1.23; 95% CI, 1.15-1.31), older individuals (RR, 1.53; 95% CI, 1.38-1.69; ≥85 compared with 65-74 years), blacks (RR, 1.17; 95% CI, 1.03-1.33), and Native Americans (RR, 1.72; 95% CI, 1.07-2.77) had increased risk of disease. After adjustment, surgeries by surgeons with low annual volume (RR, 3.80; 95% CI, 3.13-4.61 for 1-50 compared with ≥1001 annual surgeries) and less experience (RR, 1.41; 95% CI, 1.25-1.59 for 1-10 compared with ≥30 years), and surgeries performed in 2003 (RR, 1.20; 95% CI, 1.13-1.28) had increased endophthalmitis risk. CONCLUSIONS: Endophthalmitis rates are lower than previous yearly US estimates, but remain higher than rates reported from a series of studies from Sweden; patient factors or methodologic differences may contribute to differences across countries. Patient age, gender, and race, and surgeon volume and years of experience are important risk factors.

Risk factors for maternal night blindness in rural South India.

PURPOSE: This study aimed to identify risk factors associated with maternal night blindness in rural South India. METHODS: At delivery, women enrolled in a population-based trial of newborn vitamin A supplementation were asked whether they were night blind at any time during the pregnancy. Multivariate logistic regression was used to identify socioeconomic, demographic, and pregnancy-related factors associated with maternal night blindness. RESULTS: Women reported night blindness in 687 (5.2%) of 13,171 pregnancies. In a multivariate model, having a concrete roof (Odds Ratio (OR): 0.60, 95% Confidence Interval (CI): 0.47, 0.78), religion other than Hindu (OR: 0.46, 95% CI: 0.27, 0.76), maternal literacy (OR: 0.58, 95% CI: 0.49, 0.69), and maternal age from 25 to 29 years (OR: 0.68, 95% CI: 0.50, 0.93) were associated with a lower risk of night blindness in pregnancy. The odds of night blindness were higher for those leasing rather than owning land (OR: 1.78, 95%CI: 1.08, 2.93), parity 6 or more compared to 0 (OR: 2.11, 95% CI: 1.09, 4.08), and with twin pregnancies (OR: 3.23, 95% CI: 1.93, 5.41). Factors not associated with night blindness in the multivariate model were other markers of socioeconomic status such as electricity in the house, radio and television ownership, type of cooking fuel and household transportation, and number of children under 5 years of age in the household. CONCLUSIONS: Maternal night blindness was prevalent in this population. Being pregnant with twins and of higher parity put women at higher risk. Maternal literacy and higher socioeconomic status lowered the risk.

Young maternal age and the risk of neonatal mortality in rural Nepal.

OBJECTIVES: To investigate the relationship between adolescent pregnancy and neonatal mortality in a nutritionally deprived population in rural Nepal, and to determine mechanisms through which low maternal age may affect neonatal mortality. DESIGN: Nested cohort study using data from a population-based, cluster-randomized, placebo-controlled trial of newborn skin and umbilical cord cleansing with chlorhexidine. SETTING: Sarlahi District of Nepal. PARTICIPANTS: Live-born singleton infants of mothers younger than 25 years who were either parity 0 or 1 (n = 10,745). MAIN EXPOSURE: Maternal age at birth of offspring. OUTCOME MEASURE: Crude and adjusted odds ratios of neonatal mortality by maternal age category. RESULTS: Infants born to mothers aged 12 to 15 years were at a higher risk of neonatal mortality than those born to women aged 20 to 24 years (odds ratio, 2.24; 95% confidence interval, 1.40-3.59). After adjustment for confounders, there was a 53% excess risk of neonatal mortality among infants born to mothers in the youngest vs oldest age category (1.53; 0.90-2.60). This association was attenuated on further adjustment for low birth weight, preterm birth, or small-for-gestational-age births. CONCLUSIONS: The higher risk of neonatal mortality among younger mothers in this setting is partially explained by differences in socioeconomic factors in younger vs older mothers; risk is mediated primarily through preterm delivery, low birth weight, newborns being small for gestational age, and/or some interaction of these variables. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00109616.

The economic burden of major adult visual disorders in the United States.

OBJECTIVE: To estimate the societal economic burden and the governmental budgetary impact of the following visual disorders among US adults aged 40 years and older: visual impairment, blindness, refractive error, age-related macular degeneration, cataracts, diabetic retinopathy, and primary open-angle glaucoma. DESIGN: We estimated 3 components of economic burden: direct medical costs, other direct costs, and productivity losses. We used private insurance and Medicare claims data to estimate direct medical costs; epidemiologic evidence from multiple published sources to estimate other direct costs, such as nursing home costs; and data from the Survey of Income and Program Participation to estimate productivity losses. We used budgetary documents and our direct medical and other direct cost estimates to approximate the governmental budgetary impact. RESULTS: We estimated that the annual total financial burden of major adult visual disorders is $35.4 billion ($16.2 billion in direct medical costs, $11.1 billion in other direct costs, and $8 billion in productivity losses) and that the annual governmental budgetary impact is $13.7 billion. CONCLUSIONS: Major visual disorders among Americans older than 40 years result in substantial economic costs for the US economy. Well-designed public health programs may have the ability to reduce this burden in the future.

Evaluation of non-specific effects of infant immunizations on early infant mortality in a southern Indian population.

OBJECTIVE: The aim of this study was to assess the relationship between receipt of routine childhood immunizations and infant mortality before 6 months of age. METHODS: This was an observational study of 10,274 infants, in a randomized trial of vitamin A supplementation, who received the study dose and survived to at least 1 week of age. The primary outcome was mortality before 6 months of age, analysed in Cox regression models as a function of vaccine receipt and gender. RESULTS: Receipt of Bacille Calmette Guerin (BCG) or diphtheria, tetanus, polio (DTP) vaccine was associated with significant reductions of one-half to two-thirds of mortality hazards; among girls, those who received both BCG and DTP experienced higher mortality than those who received only one of the two vaccines (hazards ratio 2.4; 95% confidence interval 1.2-5.0). CONCLUSION: The reduced mortality rate associated with receipt of BCG or DTP may be due to both biological and selection factors; the analyses regarding the combined effect of these vaccines and gender need to be replicated in other settings.

The incidence of endophthalmitis after cataract surgery among the U.S. Medicare population increased between 1994 and 2001.

OBJECTIVE: To estimate the annual incidence rate of presumed endophthalmitis after cataract surgery, evaluate any changes in this rate over time, and examine demographic risk factors for endophthalmitis after cataract surgery. DESIGN: Population-based review of Medicare beneficiary claims data. DATA SOURCE: Medicare 5% sample beneficiary data files for inpatient and outpatient claims from 1994 through 2001 were examined to identify all cataract surgeries and subsequent cases of presumed endophthalmitis after cataract surgery. METHODS: All cataract surgery and presumed endophthalmitis cases after cataract surgery were identified based on claims submitted. The annual rate of presumed endophthalmitis after cataract surgery was calculated, and demographic risk factors for endophthalmitis were examined using multivariate models. MAIN OUTCOME MEASURES: Incidence rate of endophthalmitis after cataract surgery and prevalence of demographic risk factors for endophthalmitis over an 8-year period. RESULTS: One thousand twenty-six cases of presumed endophthalmitis occurred after 477,627 cataract surgeries, yielding an incidence rate of 2.15 per 1000 for this 8-year period. Rates of endophthalmitis adjusted for age, gender, and race were significantly higher in 1998 to 2001 than in earlier years (relative risk [RR], 1.41; 95% confidence interval [CI], 1.24-1.60). Older age and black race also were associated with increased risk of endophthalmitis (RR, 1.83; 95% CI, 1.19-2.81; age, > or =90 years, and RR, 1.30; 95% CI, 1.02-1.65, respectively). CONCLUSIONS: Analysis of Medicare claims data suggests that the incidence of endophthalmitis after cataract surgery has been increasing, but does not provide an explanation for this occurrence. An increase in the incidence of endophthalmitis after cataract surgery is of concern, because cataract surgery is the most commonly performed operation in the United States, and the number of cataract surgeries performed annually will likely increase substantially over the coming decades due to the aging of the U.S. population.