Evaluation of socio-economic inequalities in the use of maternal health services in rural western China.

OBJECTIVES: To describe the use of maternal health services according to the standards of the Chinese Ministry of Health, and assess socio-economic inequalities in usage in rural Shaanxi province, western China. STUDY DESIGN: Cross-sectional survey. METHODS: Principal components analysis was used to measure the economic status of households. A concentration index (CI) approach was used as a measure of socio-economic inequalities in the use of maternal health services, and a decomposable CI was used to identify the factors that contributed to the socio-economic inequalities in usage. RESULTS: In total, 4760 women who had given birth in the preceding three years were selected at random to be interviewed in the five counties. Household wealth index was calculated by constructing a linear index from asset ownership indicators using principal components analysis to derive weights. The CI approach is a standard measure in the analysis of inequalities in health. If the CI for the use of maternal health services is positive, it is pro-rich; if it is negative, it is pro-poor. The decomposition method was used to estimate the contributions of individual factors to CI. The overall CI for five or more prenatal visits was 0.075. The household wealth index was found to make the greatest contribution to socio-economic inequalities for five or more prenatal visits (35.5%), followed by maternal education (28.8%), receipt of a health handbook during pregnancy (12.1%), age group (11.0%), distance from health facility (10.5%), family members (1.5%) and district of residence (0.6%). CONCLUSIONS: Socio-economic inequalities in the use of prenatal health services were pro-rich in rural western China. Socio-economic inequalities in hospital delivery and postnatal health check-ups were not evident. Improving household economic status, providing prenatal health services for women with low income and low educational level, providing health handbooks and improving traffic conditions should be promoted as methods to eliminate socio-economic inequalities in the use of maternal health services.

Changes in adiposity indicators of Ho Chi Minh City adolescents in a 5-year prospective cohort study.

OBJECTIVE: The aim of this study was to examine changes over 5 years in body mass index (BMI) and waist circumference (WC) of adolescents from Ho Chi Minh City by age, gender and household economic status. METHODS: Anthropometry including height, weight and WC measurements of 759 secondary high school students were collected 1-year apart in a prospective cohort study, between 2004 and 2009. BMI was calculated and overweight/obesity was defined using International Obesity Task Force (IOTF) BMI cutoffs. Abdominal 'overweight' and 'obesity' were defined as WC >91st-97th and 98th centile, respectively. BMI z-scores were also created. RESULTS: Over the 5-year period, the absolute changes in mean BMI and WC were statistically significant (P<0.001). Boys had higher BMI and WC values than girls (P<0.001). The prevalence of overweight and obesity defined by IOTF BMI cutoff values increased gradually from 12.5% and 1.7% in the first year to 16.7% and 5.1% in the last year. Using WC cutoff values, the prevalence of abdominal overweight and obesity increased from 12.9% and 1.8% to 18.5% and 6.6%, respectively. BMI z-score curves shifted towards the right-hand side of the distribution (that is, towards overweight and obesity). CONCLUSION: Overweight and obesity, as measured by BMI or WC, continued to increase among adolescents of Ho Chi Minh City over the 5-year period.

Validity of referral hospitals for the toxicovigilance of acute poisoning in Sri Lanka.

OBJECTIVE: To identify the hospital admission data set that best captures the incidence of acute poisoning in rural Sri Lanka. METHODS: Data were collected on all acute poisoning cases admitted to 34 primary and 1 referral hospital in Anuradhapura district from September 2008 to January 2010. Three admission data sets were compared with the "true" incidence of acute poisoning to determine the systematic bias inherent to each data set. "True" incidence was calculated by adding all direct admissions (not transfers) to primary hospitals and to the referral hospital. The three data sets were: (i) all admissions to primary hospitals only; (ii) all admissions to the referral hospital only (direct and referrals), and (iii) all admissions to both primary hospitals and the referral hospital ("all admissions"). The third is the government's routine statistical method but counts transfers twice, so for the study transferred patients were counted only once through data linkage. FINDINGS: Of 3813 patients admitted for poisoning, 3111 first presented to a primary hospital and 2287 (73.5%) were later transferred to the referral hospital, where most deaths (161/177) occurred. All data sets were representative demographically and in poisoning type, but referral hospital data yielded a more accurate case-fatality rate than primary hospital data or "all admissions" data. Admissions to primary hospitals only or to the referral hospital only underestimated the incidence of acute poisoning by about 20%, and data on "all admissions" overestimated it by 60%. CONCLUSION: Admission data from referral hospitals are easily obtainable and accurately reflect the true poisoning incidence.

Low sleep and low socioeconomic status predict high body mass index: a 4-year longitudinal study of Australian schoolchildren.

OBJECTIVE: The objective of this study was to examine the longitudinal relationships between body mass index (BMI), sleep duration and socioeconomic status (SES) in a 4-year cohort of 939 children aged 7-12 years. METHODS: Children and their mothers completed an annual questionnaire to assess usual weekday sleep and wake times, amount of sleep, physical activity, parental education and school SES. 93% of children were enrolled (939/1010) and retention was 88%, 83% and 81% in consecutive years. Height and weight were measured annually. RESULTS: BMI increased with decreasing amount of sleep and less sleep predicted greater International Obesity Task Force measures of obesity and overweight. In all 4 years, after controlling for baseline BMI, low SES was a significant predictor of high BMI. Children in the upper tertile of sleep in year 1 had a 2.3 kg lower weight gain (standard error [SE]: 0.5) between years 1 and 4 (P < 0.0001) than children in the lower tertile of sleep and a 0.45 kg m(-2) lower increase in BMI (SE: 0.15) (P = 0.004). The difference between children with consistently low and high sleep duration over 4 years was 1 BMI point. Those with the lowest BMI were the children with both high SES and high sleep duration. PA was not associated with BMI. CONCLUSIONS: Both low SES and short sleep duration predict obesity risk in children after controlling for baseline BMI and this trend becomes stronger as children enter adolescence. Obesity prevention should include a sleep promotion component and this may be more beneficial to children of low SES and/or socially disadvantaged backgrounds.

Modifying effect of maternal nutritional status on the impact of maternal multiple micronutrient supplementation on birthweight in Indonesia.

BACKGROUND/OBJECTIVE: Low birthweight (LBW) and intrauterine growth restriction are linked with maternal nutritional status during pregnancy, and maternal supplementation with multiple micronutrients (MMNs) is reported to increase birthweight. Responses to MMN, however, might be modified by maternal nutrition. SUBJECTS/METHODS: To examine the differential effects of maternal nutritional status on birthweight responses to prenatal MMN supplementation, data from the Supplementation with Multiple Micronutrient Intervention Trial, a cluster-randomized trial in Indonesia was analyzed. Birthweight outcomes of 7001 infants whose mothers received iron/folic acid were compared with 7292 infants whose mothers received MMN. The modifying effects of maternal short-term nutritional status (mid-upper arm circumference (MUAC) and long-term nutritional status (height) on the birthweight response to MMN supplementation were assessed. RESULTS: For women with higher MUAC (≥23.5 cm), MMN increased mean birthweight by 33 g (95% confidence interval (CI): -1 to 66, P=0.06) and significantly reduced LBW by 21% (relative risk: 0.79, 95% CI: 0.64-0.99, P=0.04). The modifying effect of MUAC on mean birthweight, LBW and small for gestational age was significant. There was no evidence of a modifying effect of maternal height on the response to MMN. CONCLUSIONS: Supplementation with MMN in pregnancy increased birthweight, but maternal nutritional status modified this response, with infants born to women with better short-term nutrition having greater birthweight response.

Factors associated with non-utilisation of postnatal care services in Indonesia.

BACKGROUND: Postnatal care helps prevent neonatal deaths. This study aims to examine factors associated with non-utilisation of postnatal care in Indonesia. METHODS: A cross-sectional analytic study was conducted using data from the 2002-3 Indonesia Demographic and Health Survey (IDHS), which used multistage cluster random sampling. Contingency table and logistic regression analyses were used to determine the factors associated with non-utilisation of postnatal care services. The population attribution risk percentage (PAR%) for non-utilisation of postnatal care services was also calculated. RESULTS: Data were available for 15,553 singleton live-born infants. The prevalence of non-attendance at postnatal care services was consistently higher in rural areas than in urban areas. Maternal factors associated with lack of postnatal care included low household wealth index, low education levels, lack of knowledge of pregnancy-related complications or where distance from health services was a problem. Infants of high birth rank and those reported to be smaller than average were less likely to receive postnatal care. Other indicators of access to healthcare services which were associated with non-utilisation of postnatal care services included few antenatal care checks, use of untrained birth attendants and births outside healthcare facilities. CONCLUSION: Public health interventions to increase the utilisation of postnatal care services should target women who are poor, less educated, from rural areas and who use untrained birth attendants. Strategies to improve the availability and accessibility of antenatal care services and skilled birth attendance including focused financial support and health promotion programmes, particularly in the rural areas, should increase utilisation of postnatal care services in Indonesia.

Factors associated with haemoglobin concentration among Timor-Leste children aged 6-59 months.

The study was conducted to assess the prevalence of and factors associated with haemoglobin (Hb) concentrations among children aged 6-59 months in Timor-Leste. The 2003 Demographic and Health Survey was a multi-stage cluster survey of 4,320 households from four different geographic regions in Timor-Leste. In total, 4,514 children aged 6-59 months were included in the analysis. The prevalence of anaemia (Hb concentration <11.0g/dL) was 38.2% (638/1,668) for children aged 6-23 months and 22.6% (644/2,846) for older children (p<0.001). Girls had a higher mean Hb concentration than boys (11.9g/dL vs 11.7g/ dL, p<0.006) and children who had diarrhoea in the previous two weeks had a lower Hb concentration than children without diarrhoea (11.5g/dL vs 11.9g/dL, p<0.001). Children from the richest and middle-class households had a lower average Hb concentration than those from the poorest households (11.8g/ dL, 11.7g/dL vs 12.0g/dL, p<0.001). Children of mothers with some secondary or more education had a lower mean Hb concentration than children of mothers with completed primary, some primary and no education (11.7 g/dL vs 11.9 g/dL, 11.8 g/dL, and 11.9 g/dL, p=0.002). Children from severely-anaemic mothers had a lower mean Hb concentration than children from moderately-, mild and not anaemic mothers (10.5 g/dL vs 11.1 g/dL, 11.6 g/dL, 12.0 g/dL, p<0.001). After backward stepwise hierarchical multiple regression, wasting, male sex, recent diarrhoea, household wealth index (richest and middle-class), maternal educational status (some secondary or more and some primary), and maternal anaemic status were significantly associated with a lower Hb concentration in children and increased age of child and duration of breastfeeding (6 months) with a higher Hb concentration. Anaemia-prevention programmes among children in Timor-Leste should focus on those children aged less than two years, children with recent diarrhoea, wasted children, high socioeconomic status, and anaemic mothers.

Factors associated with adolescents' overweight and obesity at community, school and household levels in Xi'an City, China: results of hierarchical analysis.

OBJECTIVE: To identify personal and environmental factors associated with adolescent overweight and obesity in Xi'an city, China. SUBJECTS/METHODS: A total of 1804 adolescents from 30 junior high schools in six districts in Xi'an City. Community, school, household and individual characteristics were self reported by parents, school doctors and students. Factors associated with adolescent overweight and obesity were identified using a hierarchical logistic regression. RESULTS: In all adolescents, after adjustment for age and gender, factors significantly associated with overweight and obesity were: living in urban districts (odds ratio (OR): 4.0, 95% confidence interval (CI): 2.7-6.0); limited use of school sports facilities (OR: 1.7, 95% CI: 1.1-2.6); wealthy households (OR: 1.7, 95% CI: 1.1-2.6); parental restrictions on purchasing snacks (OR: 1.5, 95% CI: 1.03-2.0); having an overweight/obese parent (OR: 1.8, 95% CI: 1.3-2.5); having soft drinks more than four times per week (OR: 1.6, 95% CI: 1.02-2.5) and not fussy about foods (OR: 1.7, 95% CI: 1.2-2.2). Eating sweets was negatively associated with overweight/obesity (OR: 0.6, 95% CI: 0.4-0.9). Separate gender analyses revealed that in boys, low physical activity (OR: 2.0, 95% CI: 1.1-3.8) and higher energy intake (OR: 1.8, 95% CI: 1.1-2.9) were also associated with overweight/obesity. In girls, less school sports meetings (OR: 2.3, 95% CI: 1.3-4.0); parental decisions about eating fast foods (OR: 1.8, 95% CI: 1.1-2.9) and availability of home video games (OR: 1.7, 95% CI: 1.1-2.5) were also significant. CONCLUSIONS: Preventive strategies for adolescent overweight and obesity in Xi'an should address the community and school environments to reinforce behavioral change. Gender differences also need to be considered when planning interventions.

Breastfeeding practices and associated factors among children under 24 months of age in Timor-Leste.

OBJECTIVE: To describe breastfeeding practices and to assess the sociodemographic factors associated with selected breastfeeding indicators. DESIGN AND SETTING: The 2003 Demographic and Health Survey was a multi-stage cluster sample survey of 4320 households from four different geographic areas in Timor-Leste. SUBJECTS: A total of 2162 children aged 0-23 months. RESULTS: A high proportion (97.6%) of infants had been ever breastfed, but only 46.1% had initiated breastfeeding within the first hour of birth. Seventy-eight percent of children <24 months were currently breastfed, 30.7% of infants <6 months were exclusively breastfed and 12.5% of infants <12 months were bottle-fed. A high proportion of infants of 6-9 months (82.0%) were receiving complementary food in addition to breast milk. Multivariate analysis revealed that exclusive breastfeeding was significantly lower in the rural west region (odds ratio (OR)=3.15) compared to the urban region, and among those from richest households (OR=1.90) compared to poorest. Mothers with primary education were significantly more likely to exclusively breastfeed than mothers with no education (OR=0.62). Increasing age of the infant was associated with significantly less current (OR=1.23) and exclusive (OR=1.35) breastfeeding. Continuation of breastfeeding at the end of the first year was significantly lower in non-working mothers (OR=1.58) compared to working mothers, and among infants born in health-care facilities (OR=2.16) than those born at home. CONCLUSIONS: Breastfeeding practices in Timor-Leste were satisfactory, except the exclusive breastfeeding at 6 months. However, more socioeconomically privileged groups demonstrated a poorer breastfeeding performance than disadvantaged groups. Further breastfeeding promotion programmes are needed across all population groups, and should include health-care providers and maternity institutions.

Obesity in adults: an emerging problem in urban areas of Ho Chi Minh City, Vietnam.

OBJECTIVE: To assess the prevalence of overweight, obesity and underweight among Vietnamese adults living in urban areas of Ho Chi Minh City (HCMC), Vietnam. DESIGN: This cross-sectional survey was conducted in the local health stations of 30 randomly selected wards, which represent all 13 urban districts of HCMC, over a period of 2 months from March to April 2004. SUBJECTS: A total of 1488 participants aged 20-60 years completed the interview, physical examination and venous blood collection. MEASUREMENTS: Anthropometric measurements of body weight, height, waist and hip circumference were taken to construct indicators of adiposity including body mass index (BMI), waist circumference, and waist-to-height and waist-to-hip ratios. Both systolic and diastolic blood pressure and biochemical indicators of cardiovascular disease and type II diabetes risk (lipid profile and fasting blood glucose) were also measured. RESULTS: The age and sex standardized prevalence of overweight and obesity using Asian specific BMI cutoffs of 23.0 and 27.5 kg/m2 was 26.2 and 6.4%, respectively. The prevalence of overweight and obesity was slightly higher in females (33.6%) than males (31.6%), and progressively increased with age. The age and sex-standardized prevalence of underweight (BMI <18.5 kg/m2) among Vietnamese adults living in HCMC was 20.4%. The prevalence was slightly higher in males (22.0%) than in females (18.9%), and there was a much higher prevalence in all underweight categories in younger women than in men but this was reversed for older men. CONCLUSION: The adult population in HCMC Vietnam is in an early 'nutrition transition' with approximately equal prevalence of low and high BMI. The prevalence of overweight and obesity of Vietnamese urban adults was lower than that reported for other east and southeast Asian countries.

Incidence of surgical site infections and accompanying risk factors in Vietnamese orthopaedic patients.

A cohort study of surgical site infections (SSIs) was conducted in 582 orthopaedic surgical patients at Cho Ray Hospital, a reference hospital in Ho Chi Minh City, Vietnam, in order to determine the incidence and analyse risk factors for SSIs in this population. The SSI incidence rate was 12.5% (73 of 582); 3.6% incisional SSIs, 6.8% deep incisional SSIs and 2.1% organ/space SSIs. The incidence increased from 2% in clean wounds to 44.6% in dirty wounds, or 1.3% in patients with a National Nosocomial Infections Surveillance (NNIS) risk index of 0 to 75% in patients with an NNIS risk ratio of 3. In multi-variate analysis, having a dirty wound [odds ratio (OR) 8.7; 95% confidence intervals (CI) 4.6--16.4], American Society of Anesthesiologists' score >2 (OR 3.9; 95%CI 1.8-8.8), procedures with external fixation (OR 2.9; 95%CI 1.4-5.9), emergency surgery with motor-vehicle-related trauma (OR 2.1; 95%CI 1.2-3.9), or duration of procedure >2h (OR 2.1; 95%CI 1.1-4.2) were independent risk factors for SSI. Lack of appropriate prophylaxis was of borderline significance (OR 3.2; 95%CI 0.9-11.1, P=0.06). Among 76 patients with SSIs, 22 patients were discovered during postdischarge follow-up. These late SSIs had age as an additional risk factor (OR 2.8; 95%CI 1.1-7.2). Our data show that SSIs were frequent and differed widely by wound class. The NNIS risk index was predictive of SSI for this population. With a high number of motor vehicle accidents in Vietnam, the majority of orthopaedic operations are trauma related. Emergency surgery for injuries sustained in these accidents, and procedures with external fixation were especially prone to infections.

Antimicrobial use in children under five years with diarrhea in a central region province, Thailand.

This cross-sectional study aimed to estimate the prevalence of appropriate antimicrobial prescribing for treating childhood diarrhea within the public hospital system in a central region province, Thailand. Reported are findings of a prospective clinical audit of 424 cases treated by 38 physicians. Appropriate use of antimicrobials was defined as prescribing antimicrobials for managing an invasive bacterial-type, bloody diarrhea or not prescribing antimicrobials for managing a watery-type or non-bloody diarrhea. Among 424 cases with diarrhea, 12.5% were invasive bacterial-type. Of the 66 diarrheal episodes in which stool samples were cultured, 7 stool specimens were positive, two with Shigella sonnei, two with Vibrio cholerae Ogawa and three with E. coli. Based on the presence of mucus and blood in stools, 27.4% of 424 cases received appropriate antimicrobial drugs. Cotrimoxazole was the most commonly prescribed drug (51%), followed by colistin sulfate (15.3%), norfloxacin (11%), and nalidixic acid (0.5%). The average number of antimicrobials per case of inpatients was higher than outpatients (1.15 vs 0.84, p < 0.001). There was a trend toward prescribing norfloxacin in childhood diarrhea. The Ministry of Public Health should continue providing effective interventions aimed at improving physicians' knowledge of diarrhea treatment. Similar efforts should be directed toward improving caretakers' knowledge about home care for childhood diarrhea and encouraging widespread correct use of oral rehydration therapy (ORT) in the community. Hopefully, such activities will help reduce the inappropriate use of antimicrobial agents in treating diarrheal disease.

Receiver operating characteristic analysis of body mass index to detect increased risk of functional morbidity in Vietnamese rural adults.

OBJECTIVE: To assess the performance of low BMI, and define optimal BMI cut-off values in order to detect fever-associated adult morbidity. DESIGN: A cohort study of adults between 18 and 60 y in rural Vietnam, whose BMI and health status were assessed at baseline, and who were then monitored for illness events for 4 months. Nonparametric receiver operating characteristic (ROC) analysis was used to evaluate the performance of low BMI to detect the average number of restricted-days due to illness and to determine optimal cut-off values. SETTING: A rural commune in the Red River Delta, northern Vietnam. SUBJECTS: The study included 693 men and 739 women aged 18-60-y. RESULTS: At baseline, 21% of the study participants had a BMI<18.5 kg/m(2). As BMI progressively decreased, the percentage of participants experiencing morbidity with fever increased. The areas under the ROC curves for BMI were significantly greater than 0.5 for all levels of monthly average restricted-days of illness (MARDI) with fever, with best performance for >5 days/month. Excluding participants with acute or chronic disease at baseline improved the performance of BMI to detect MARDI with fever of >5 days (area under ROC curve 0.95; 95% CI 0.92, 0.99). With increasing levels of MARDI with fever, BMI cut-offs fell to 17.9 kg/m(2) when MARDI with fever was >5 days. CONCLUSIONS: The ROC analysis demonstrates that low BMI performs well as a risk indicator of MARDI with fever of >5 days with an optimal BMI cut-off value of 17.9 kg/m(2).

Complex interactions with infection and diet may explain seasonal growth responses to vitamin A in preschool aged Indonesian children.

OBJECTIVE: To explore the potential contribution of respiratory infections and vitamin A intakes to the seasonal effect of vitamin A supplementation on child growth. METHODS: Data from a randomized double-blind placebo-controlled trial, in which a single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months were used for the analysis. In total, 4430 child-treatment cycles were examined, and for each cycle the children had their dietary intake, weight, and height assessed at the start and end. Linear regression models of the difference in height and weight during each treatment cycle were used and the within-child correlation was adjusted using the generalized estimating equations (GEE). Other covariables in the model included age, sex, percentage of days with acute lower respiratory infection and diarrhea, and cumulative doses of vitamin A. RESULTS: This study showed that a significant effect of vitamin A supplementation on linear growth was observed in all seasons in children with a low burden of respiratory infections, that is, < 21.5% of days with respiratory illness. In each season, the highest effect was found in children with a low burden of respiratory infections and low vitamin A intakes, that is, intakes < 400 RE/day. Children with a high burden of respiratory infections or high vitamin A intakes benefited less from vitamin A supplementation for their linear growth than children with a low burden of respiratory infections and low vitamin A intakes. Finally, there was no benefit for linear growth from vitamin A supplementation in children with both a high burden of respiratory infections and high vitamin A intakes regardless of the season. CONCLUSIONS: The effect of vitamin A supplementation on growth is dependent on season. Respiratory infections and vitamin A intakes are important factors underlying the seasonal effect of vitamin A supplementation on growth.

Vitamin A supplementation selectively improves the linear growth of indonesian preschool children: results from a randomized controlled trial.

BACKGROUND: Vitamin A deficiency is associated with stunting and wasting in preschool children, but vitamin A supplementation trials have not shown a consistent effect on growth. OBJECTIVE: We examined the effect of vitamin A supplementation on height and weight increments among Indonesian preschool children. DESIGN: Data were obtained from a randomized, double-masked, placebo-controlled trial of rural Javanese children aged 6-48 mo. Children received 206000 IU vitamin A (103000 IU if aged <12 mo) or placebo every 4 mo. RESULTS: High-dose vitamin A supplementation modestly improved the linear growth of the children by 0.16 cm/4 mo. The effect was modified by age, initial vitamin A status, and breast-feeding status. Vitamin A supplementation improved height by 0.10 cm/4 mo in children aged <24 mo and by 0.22 cm/4 mo in children aged >/=24 mo. The vitamin A-supplemented children with an initial serum retinol concentration <0.35 micromol/L gained 0.39 cm/4 mo more in height and 152 g/4 mo more in weight than did the placebo group. No growth response to vitamin A was found among children with an initial serum retinol concentration >/=0.35 micromol/L. In non-breast-fed children, vitamin A supplementation improved height by 0.21 cm/4 mo regardless of age. In breast-fed children, vitamin A supplementation improved linear growth by approximately 0.21 cm/4 mo among children aged >/=24 mo, but had no significant effect on the growth of children aged <24 mo. CONCLUSION: High-dose vitamin A supplementation improves the linear growth of children with very low serum retinol and the effect is modified by age and breast-feeding.

Respiratory infections reduce the growth response to vitamin A supplementation in a randomized controlled trial.

BACKGROUND: Studies on the effect of vitamin A supplementation on growth have yielded various results. It is possible that such growth is dependent on the burden of infectious diseases in the population. METHODS: We analysed data from a randomized, double-masked, placebo-controled trial to examine the role of respiratory infections and diarrhoea in modifying the growth response to vitamin A supplementation. A single high dose of vitamin A or placebo was given every 4 months to 1405 children aged 6-48 months, and 4430 child treatment cycles were used in this analysis. RESULTS: Vitamin A supplementation modestly improved linear but not ponderal growth of children who experienced little respiratory infection and especially of those who had vitamin A intake below the normative requirement (<400 RE/day). Children who received vitamin A and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height than the placebo group, but those with > or =21.5% of days of respiratory infection did not show a significant growth response to vitamin A supplementation. Children who experienced no respiratory infection and had vitamin A intake <400 RE/day benefited most, gaining 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height compared to the placebo group. Diarrhoea was associated with poorer growth, but did not significantly modify the effect of vitamin A supplementation on growth. CONCLUSIONS: Vitamin A supplementation improves the linear growth of children who have a low intake of vitamin A but this impact is muted with increasing levels of respiratory infections.

PIP: This randomized, double-masked, placebo-controlled trial study examined the role of respiratory infections and diarrhea in modifying the growth response to vitamin A supplementation. A total of 1405 children aged 6-48 months were given a single high dose of vitamin A or placebo every 4 months, and 4430 child treatment cycles were used in this analysis. The study was conducted in two rural subdistricts located on the southern coast of central Java, Indonesia. Analytic findings indicate that vitamin A supplementation resulted in a modest improvement in the linear and not in the ponderal growth of children. Those who had an adequate intake of 400 RE/day and were free of respiratory infection grew 0.22 cm/4 months (95% CI: 0.08, 0.37) more in height. Conversely, there were no significant growth responses to vitamin A supplementation among children with 21.5% of days or higher of respiratory infection. In addition, children who experienced no respiratory infection and had vitamin A intake below the normative requirement (400 RE/day) gained 0.31 cm/4 months (95% CI: 0.10, 0.52) more in height than the placebo group. Moreover, diarrhea was associated with poorer growth but did not modify the effect of vitamin A supplementation on growth. In conclusion, vitamin A supplementation improves linear growth in children but not among those with a high prevalence of respiratory infections.

Randomised trial of different rates of feeding in acute diarrhoea.

OBJECTIVE: To compare the effect of different feeding frequencies on the speed of recovery from diarrhoea. METHODS: A randomised, non-blinded trial provided 0.452 MJ/kg/day as either 6 or 12 feeds of cows' milk each day to 262 hospitalised male infants aged 3-12 months with acute diarrhoea. Stool frequency, stool weight, body weight, and diarrhoea complications were monitored until recovery or for 14 days. RESULTS: A proportional hazards regression model controlling for age, diarrhoea aetiology, and severity of dehydration on admission revealed that the frequently fed group had a significantly shorter duration of diarrhoea (hazards ratio, 1.29; 95% confidence interval, 1.002 to 1.653). Frequently fed infants had a significantly greater weight gain and significantly lower faecal frequency and faecal weight. CONCLUSIONS: Breast feeding remains the preferred method of feeding infants with acute diarrhoea, but feeding cows' milk to adequately nourished infants with acute diarrhoea is safe and is more rapidly effective if provided in frequent feeds with low energy loads.

The National Survey on the Constitution and Health of Chinese Students in 1995: Nutritional status of school students aged 10-17 years in Shaanxi, China.

There are 200 million Chinese adolescents and they represent a significant proportion of the world adolescent population. Their health, growth and nutritional status is of vital importance to China but also to the health of adolescents globally. Previous assessments of nutritional status of adolescents in China have been undertaken without using World Health Organization (WHO) recommended anthropometric methods or reference data. Using data from the National Survey on the Constitution and Health of Chinese Students in 1995 (NSCHCS-95), this study aimed to assess the current nutritional status of Shaanxi school students using WHO recommended methods of nutritional assessment. Data for 6284 (3142 females and 3142 males) Shaanxi school students aged 10-17 years was abstracted from the Shaanxi portion of the NSCHCS-95. This national cross-sectional survey gathered anthropometric measurements using standard methods, maturity indicators, and basic social and demographic data. The calculation of anthropometric indicators was based on the National Centre for Health Statistics/WHO reference data and the prevalence of nutritional status indicators was estimated using standard WHO recommended cut-offs and methods of maturity adjustment. The median age of menarche and spermarche was delayed for Shaanxi rural female and male students in comparison with the reference data by 0.81 and 0.39 years, respectively. The prevalence of stunting and thinness in students in almost all ages was higher than in the reference population. For all age groups combined, the adjusted prevalence of stunting was 8.0% for urban students, and 11.0% for rural students. For students under 14 years of age, the adjusted prevalence of thinness was 18.3% for urban students, and 15.1% for rural students. The prevalence of 'at risk of overweight' and obesity among urban male students aged 10-11.99 (for overweight) and 10-12.99 years (for obesity) were similar to the reference population. Undernutrition (stunting and thinness) continues to be a public health problem in the Shaanxi school population and may be related to the less developed rural economy in the province. Young Shaanxi urban male students showed a tendency towards an excess prevalence of 'at risk of overweight' and obesity, which may be related to improved economic conditions in urban areas. It is necessary to develop national anthropometric reference data, cut-off points and median ages of attainment of WHO recommended maturational indicators for Chinese adolescents.

Multivariate time-to-event models for studies of recurrent childhood diseases.

BACKGROUND: Standard Poisson regression analyses of infectious disease incidence may not be optimal when covariates change over time. When a longitudinal study is of sufficient duration so that multiple disease episodes per person may occur, within-subject correlation may be present and require special statistical consideration. Seasonality of disease incidence is a common feature of field studies of respiratory and diarrhoeal diseases in children. Accurate analysis may require keeping the children aligned with respect to the same baseline hazard function. These data features often are ignored in the analysis of such studies. METHODS: Methods for accounting for multiple events are discussed. We propose the use of a counting process model to retain the alignment with respect to season. This model is supplemented by a simple bootstrap procedure to account for the within-child correlation. RESULTS: The bootstrap technique is illustrated with data from a randomized trial of the effects of vitamin A supplementation on childhood morbidity. Standard errors for the main effect of vitamin A are larger using the bootstrap, indicating the presence of positive correlation. CONCLUSIONS: Time-to-event models can be useful in the analysis of studies of childhood morbidity, especially for situations with seasonality, waning of effect, or multiple events. The bootstrap provides an appropriate, straightforward method for handling within-child correlation in such settings.

Vitamin A supplementation fails to reduce incidence of acute respiratory illness and diarrhea in preschool-age Indonesian children.

Vitamin A supplementation of populations of vitamin A-deficient preschool-age children has been shown to reduce childhood mortality, but the primary preventive effects of such supplements on childhood infectious diseases have not been carefully evaluated. We conducted an individually randomized, placebo-controlled, double-masked trial among 1,407 Indonesian preschool-age children, to measure the effects of high dose vitamin A on acute respiratory and diarrheal illnesses. Signs and symptoms of morbidity were monitored using every other day home surveillance by trained interviewers. High dose vitamin A supplements increased the incidence of acute respiratory illnesses (ARI) by 8%, and acute lower respiratory illnesses (ALRI) by 39%. These detrimental effects on acute lower respiratory illnesses were most marked in children with adequate nutritional status (rate ratio 1.83, 95% confidence interval 1.257-2.669). In contrast, vitamin A tended to be protective of ALRI in chronically malnourished children (rate ratio 0.71, 95% confidence interval 0.375-1.331). There was no overall effect of high-dose vitamin A supplements on the incidence of diarrheal disease (rate ratio 1.06, 95% confidence interval 0.920-1.225). However, we found a significant interaction between supplementation and age: vitamin A increased the incidence of diarrhea in children < 30 mo of age, but tended to reduce the incidence in older children. The finding of a significant adverse effect of vitamin A supplements in adequately nourished children highlights the need to review the criteria for selecting populations of preschool-age children for vitamin A supplementation.