title: Assessing the trend of gastroschisis prevalence in China from 1996 to 2007 using two analytical methods.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: National Center for Birth Defect Monitoring, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Xu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Dai
authors.forename: Xiuqin
authors.initials: X
authors.lastname: Yuan
authors.forename: Juan
authors.initials: J
authors.lastname: Liang
authors.forename: Guangxuan
authors.initials: G
authors.lastname: Zhou
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Chunhua
authors.initials: C
authors.lastname: He
authors.forename: Lei
authors.initials: L
authors.lastname: Miao
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000328:Adult; D001723:Birth Rate / Q000639:trends; D002681:China / Q000453:epidemiology; D003625:Data Collection / Q000379:methods / Q000639:trends; D003627:Data Interpretation, Statistical; D005260:Female; D020139:Gastroschisis / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D011247:Pregnancy; D015995:Prevalence; D012044:Regression Analysis; D013997:Time Factors; D055815:Young Adult