Guangxuan Zhou

Mortality rate for children under 5 years of age in China from 1996 to 2006

OBJECTIVES To study the change in mortality rate for children under 5 years of age in China over the past decade, and to evaluate Chinas progress in achieving Millennium Development Goal 4. STUDY DESIGN Population-based descriptive study. METHODS A population-based survey was conducted through a nationwide multi-level surveillance network. The mortality rate and the leading causes of death for children under 5 years of age were analysed. RESULTS The mortality rate for children under 5 years of age in China dropped by 54.2% between 1996 and 2006 (from 45.0 per 1000 livebirths to 20.6). During this period, deaths due to pneumonia and diarrhoea dropped by 69.4% and 69.7%, respectively. The proportion of deaths due to pneumonia dropped from 23.4% in 1996 to 15.6% in 2006, and the proportion of deaths due to diarrhoea dropped from 5.6% in 1996 to 3.7% in 2006. CONCLUSION The mortality rate for children under 5 years of age in China dropped remarkably from 1996 to 2006. This reduction was mainly due to a significant decrease in deaths due to pneumonia and diarrhoea. Based on the survey results, China should be able to achieve Millennium Development Goal 4.

Time trends and geographic variations in the prevalence of hypospadias in China

BACKGROUND Little is known about the main epidemiologic characteristics of hypospadias prevalence in China. We investigated the time trends and geographic variations in the prevalence of hypospadias in China from 1996 to 2008. METHODS Data were retrieved from the hospital-based birth defects monitoring system in China from 1996 to 2008. We used prevalence ratios (PRs) to describe the difference in prevalence of hypospadias between urban and rural areas, as well as among different regions. Poisson regression was used to explore the long time trend for the prevalence of hypospadias and its regional disparity. RESULTS The prevalences of hypospadias for isolated anomalies, multiple anomalies, and overall cases were 7.64, 1.39, and 9.03 per 10,000 births, respectively. The national PRs (urban vs. rural) of hypospadias for overall and isolated cases were 1.25 (95% confidence interval [CI], 1.16-1.35) and 1.27 (95% CI, 1.17-1.38), respectively. The highest prevalence (12.10 per 10,000 births) was observed in the eastern region. A positive correlation was found between the prevalence of hypospadias and maternal age (p < 0.01). The average annual increase of 7.43% (95% CI, 5.52-9.38%) was observed in the overall prevalence of hypospadias in China; it was 5.28% (95% CI, 4.16-6.43%) in urban areas, 9.79% (95% CI, 7.72-11.90%) in rural areas, 9.08% (95% CI, 6.36-11.86%) in the eastern region, 4.76% (95% CI, 2.93-6.62%) in the central region, and 6.57% (95% CI, 4.44-8.74%) in the western region. CONCLUSION The increasing trends and differences of hypospadias prevalence by urban-rural classification and geographical location suggest that environmental exposure and maternal age might have a critical role in the development of hypospadias.

Geographic and urban–rural disparities in the total prevalence of neural tube defects and their subtypes during 2006–2008 in China: a study using the hospital-based birth defects surveillance system

BackgroundPrevious reports on the prevalence of neural tube defects (NTDs) in China did not include cases of NTDs that were less than 28 weeks of gestational age (GA) and hence did not accurately reflect the total prevalence of NTDs or the geographic and urban–rural disparities in their prevalence. This article includes cases of NTDs that were less than 28 weeks of GA.MethodsData used in this study were collected from 2006 to 2008 using a nationwide hospital-based registry, the Chinese Birth Defects Monitoring Network. The total prevalence ratio (PR) of NTDs and their subtypes, the ratios of PR (PRR), and 95% confidence intervals (CI) were used to analyse geographic disparities at both the regional (north, south) and provincial levels and to analyse disparities between rural and urban areas.ResultsOverall, the total PR of NTDs was 14.0 per 10,000 births. The PRR of NTDs of rural women between the north and south region was 2.26 (95% CI: 2.04-2.52), which was much higher than that of urban women (PRR: 1.56, 95% CI: 1.41-1.72). The three subtypes of NTDs had different geographic distribution at the level of province. The urban–rural PRR of NTDs was 2.14 (95% CI: 1.94-2.34) in the north but only 1.47 (95% CI: 1.31-1.66) in the south.ConclusionsThere is a high total prevalence of NTDs, which remains one of the major public health concerns in China. Eliminating the geographic and urban–rural disparities in the disease burden is a priority for future intervention.

Prevalence of neural tube defect pregnancies in China and the impact of gestational age of the births from 2006 to 2008: a hospital-based study

Objective: To determine the prevalence of pregnancies with neural tube defects (NTDs) in China between 2006 and 2008 and to find a better representative monitoring gestational age for total prevalence of NTDs by comparing the prevalence at or greater than 20, 22 or 28 weeks of gestation (abbreviated as P20, P22 and P28, respectively). Methods: The data were retrieved from the National Birth Defects Monitoring Network in China (the Network). All births were monitored on the prevalence of NTDs during the entire gestation period of 2006–2008. Results: The P28 only represents 34.6% of anencephaly, 70.8% of spina bifida, 53.3% of encephalocele and 53% of the combination of the three types of NTDs during the entire pregnancy. The P20 represents 75.8%, 94.7%, 86% and 85.4% in the above-mentioned categories, respectively. Of the NTDs diagnosed prenatally before 28 weeks of gestation, 45.3% were terminated electively. Conclusions: The P28 underrepresented 65.4% of anencephaly, 29.2% of spina bifida, 46.7% of encephalocele and 47% of the combined NTDs. The prevalence of NTDs that occurred at or greater than 20 weeks of gestation was more accurate than that at or greater than 28 weeks of gestation.

Assessing the trend of gastroschisis prevalence in China from 1996 to 2007 using two analytical methods.

BACKGROUND In recent years, the prevalence of gastroschisis has increased remarkably in some areas and remained unchanged in other areas; however, in general, there is a recent increasing trend compared to the 1970s and 1980s. In this study, we explored the time trend of gastroschisis prevalence in China during 1996 to 2007. METHODS Data were retrieved from the hospital-based national monitoring database maintained by the Chinese Birth Defects Monitoring Network (CBDMN). The monitored subjects were infants born on the 28th gestational week or later, including live births and stillbirths. The maximal time for the diagnosis of a congenital malformation was the seventh day after birth. The secular trends on the overall prevalence and the different feature-specific prevalence of gastroschisis in China were analyzed using the linear chi-square test and the Poisson regression model. RESULTS The overall prevalence of gastroschisis in China was 2.54 per 10,000 births during 1996 to 2007. Except for the prevalence of gastroschisis that significantly increased among infants whose mothers were 20 to 24 years old (p=0.0498 for the linear chi-square test, p=0.0032 for the Poisson regression model analysis) and significantly decreased among infants whose mothers were 30 to 34 years old (p=0.0177 for the Poisson regression model analysis), no significant changes were found in the overall and remaining feature-specific prevalences. CONCLUSION The overall prevalence of gastroschisis in China did not change remarkably during 1996 to 2007; but the prevalence of gastroschisis significantly increased among infants whose mothers were 20 to 24 years old and decreased among infants whose mothers were 30 to 34 years old.

Long-term trends and seasonality of omphalocele during 1996–2010 in China: a retrospective analysis based on the hospital-based birth defects surveillance system

BackgroundLittle is known about secular trends and seasonal variation in the birth prevalence of omphalocele in China. This study aimed to explore the long-term trends and seasonality of this birth defect, to provide insight into the etiology and prevention of omphalocele.MethodsA retrospective analysis of all births with omphalocele (1322 cases in 8.8 million births) registered in the hospital-based Chinese Birth Defects Monitoring Network between January 1996 and September 2010. Negative binomial cyclical regression models were used to analyze the long-term trends and seasonal fluctuations of omphalocele occurrence in the southern and northern regions and urban and rural areas of China.ResultsThe total prevalence of omphalocele was 1.50 cases (95% confidence interval (CI): 1.42–1.58) per 10,000 births. There was no significant secular trend of omphalocele occurrence in China between 1996 and 2010. The observed prevalence of omphalocele in rural areas was 2.03–2.54 cases per 10,000 births between May and August, which was higher than that observed in other months. The highest prevalence of births with omphalocele in rural areas occurred at the end of June; on average, the prevalence of omphalocele at that time point increased by 20% (95% CI: 6–35%) compared with other months.ConclusionsThere were no long-term trends found for occurrence of omphalocele in China between 1996 and 2010; however, seasonality was observed for omphalocele in women living in rural areas. These results may help generate hypotheses for further study of environmental factors that vary by season.