title: [Meta-analysis of effect of intervention with folic acid on neural tube defects].
abstract: OBJECTIVE
  To provide evidences for decision-making on neural tube defects prevention according to evaluating the effect of intervention with 0.4 mg folic acid on the incidence of neural tube defects in China.
  
  
  METHODS
  Meta-analysis with software of Review Manager 4.2 version was used to synthetically and quantitatively evaluate the studies included. The Peto method of fixed effect model and random effect model (DerSimonin and Laird) were applied to estimate combined effect values and their corresponding 95% confidence intervals of homogenous and inhomogenous data respectively.
  
  
  RESULTS
  Six pieces of literature included in which the studies were folic acid intervention were inhomogenous (chi2 = 13.43, P = 0. 02). Random effect model of Meta-analysis method were used. The combined effect values of intervention with folic acid on neural tube defects among women were strikingly significance (Z = 5.17, P = 0.00001). The pooled RR values were 0.36 (95% CI: 0.25-0.53).
  
  
  CONCLUSIONS
  Intervention with folic acid on neural tube defects are effective.
authors.affiliation: Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan 030001, China. jmzhak@yahoo.com.cn
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Jian
authors.forename: Jintao
authors.initials: J
authors.lastname: Wang
authors.forename: Haikui
authors.initials: H
authors.lastname: Sun
mesh_terms: D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006801:Humans; D039382:Maternal Nutritional Physiological Phenomena; D009436:Neural Tube Defects / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011295:Prenatal Care
chemical_list: D005492:Folic Acid