title: The prevalence of tic disorders for children in China: A systematic review and meta-analysis.
abstract: BACKGROUND
  Tic disorders (TD) are common neuropsychiatric disorders among children and adolescents. Still, there is great uncertainty regarding their epidemiology in China. We aim to depict the prevalence of TD for children in China and explore the influence of sex, age, geographic distribution, and diagnostic criteria on the prevalence rates.
  
  
  METHODS
  We searched PubMed, EMBASE, four Chinese electronic databases, and relevant lists. Two reviewers independently selected trials, assessed trial quality, and extracted the data.
  
  
  RESULTS
  We included 13 studies investigating 269,571 participants. The sample size ranged from 563 to 216,005 participants. The age of participants ranged from 3 to 16 years. The meta-analysis of the prevalence of TD was 6.1% [95% CI: 0.036-0.100, I = 49.7%]. The prevalence of transient tic disorder (TTD), chronic tic disorder (CTD), and Tourette syndrome (TS) was 1.7% [95% CI = 0.009-0.031, I = 49%], 1.2% [95% CI = 0.007-0.022, I = 48.3%], and 0.3% [95% CI = 0.001-0.008, I = 49.5%], respectively. The prevalence of TD in boys [5.1%, 95% CI = 0.026-0.098, I = 49.3%] was higher than that in girls [2.4%, 95% CI = 0.009-0.065, I = 49.4%]. The prevalence of TD in urban area [2.6%, 95% CI = 0.019-0.034, I = 35.5%] was higher than that in rural area [2.2%, 95% CI = 0.016-0.030, I = 33.9%]. The prevalence of TD in central China [10.7%, 95% CI = 0.043-0.242, I = 49.2%] was higher than that in North China [7.8%, 95% CI = 0.007-0.522, I = 49.9%] and East China [4.4%, 95% CI = 0.015-0.120, I = 49.8%].
  
  
  CONCLUSIONS
  TD is a common disease in China, with prevalence differing based on sex, age, and region.
authors.affiliation: Department of Pharmacy, Evidence-Based Pharmacy Center, West China Second Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children West China School of Public Health Department of Pediatrics, West China Second Hospital, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Chunsong
authors.initials: C
authors.lastname: Yang
authors.forename: Lingli
authors.initials: L
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.forename: Cairong
authors.initials: C
authors.lastname: Zhu
authors.forename: Qin
authors.initials: Q
authors.lastname: Guo
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D012737:Sex Factors; D013981:Tic Disorders / Q000453:epidemiology*