title: Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review.
abstract: BACKGROUND
  To provide a clear picture of the current hepatitis B situation, the authors performed a systematic review to estimate the age- and region-specific prevalence of chronic hepatitis B (CHB) in Turkey.
  
  
  METHODS
  A total of 339 studies with original data on the prevalence of hepatitis B surface antigen (HBsAg) in Turkey and published between 1999 and 2009 were identified through a search of electronic databases, by reviewing citations, and by writing to authors. After a critical assessment, the authors included 129 studies, divided into categories: 'age-specific'; 'region-specific'; and 'specific population group'. To account for the differences among the studies, a generalized linear mixed model was used to estimate the overall prevalence across all age groups and regions. For specific population groups, the authors calculated the weighted mean prevalence.
  
  
  RESULTS
  The estimated overall population prevalence was 4.57, 95% confidence interval (CI): 3.58, 5.76, and the estimated total number of CHB cases was about 3.3 million. The outcomes of the age-specific groups varied from 2.84, (95% CI: 2.60, 3.10) for the 0-14-year olds to 6.36 (95% CI: 5.83, 6.90) in the 25-34-year-old group.
  
  
  CONCLUSIONS
  There are large age-group and regional differences in CHB prevalence in Turkey, where CHB remains a serious health problem.
authors.affiliation: Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Dr, Molewaterplein 50,3000 CA Rotterdam, the Netherlands. m.toy@erasmusmc.nl
authors.forename: Mehlika
authors.initials: M
authors.lastname: Toy
authors.forename: Fatih Oguz
authors.initials: FO
authors.lastname: Önder
authors.forename: Tanja
authors.initials: T
authors.lastname: Wörmann
authors.forename: A Mithat
authors.initials: AM
authors.lastname: Bozdayi
authors.forename: Solko W
authors.initials: SW
authors.lastname: Schalm
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Borsboom
authors.forename: Joost
authors.initials: J
authors.lastname: van Rosmalen
authors.forename: Jan Hendrik
authors.initials: JH
authors.lastname: Richardus
authors.forename: Cihan
authors.initials: C
authors.lastname: Yurdaydin
mesh_terms: D000367:Age Factors; D005260:Female; D005843:Geography; D006509:Hepatitis B / Q000453:epidemiology*; D006801:Humans; D008297:Male; D015995:Prevalence; D014421:Turkey / Q000453:epidemiology