title: Nocturnal enuresis and overactive bladder in children: an epidemiological study.
abstract: OBJECTIVE
  To investigate the prevalence and characteristics of nocturnal enuresis (NE) and to examine the prevalence of overactive bladder (OAB) symptoms in primary schoolchildren.
  
  
  METHODS
  After conducting an anonymous questionnaire survey about voiding habits and bowel habits in primary schoolchildren, a total of 6917 schoolchildren belonging to 11 primary schools were randomly enrolled in the survey. According to the International Continence Society, we defined NE as any involuntary loss of urine during sleep, occurring more frequently than once per month. Children with NE were subdivided into two groups, monosymptomatic NE (MNE) and enuretic syndrome (ES). To evaluate the characteristic differences of MNE and ES, we assessed the relationships between NE and voiding habits, and episodes of cystitis and constipation. Overactive bladder was defined as increased daytime frequency and/or urge urinary incontinence, and its prevalence was investigated.
  
  
  RESULTS
  The response rate to the questionnaire was 76.4%. The prevalence of NE was 5.9% and was inversely related to increasing age. Monosymptomatic NE comprised 59.4% of NE cases. The annual spontaneous resolution rate of MNE was higher than that of ES. Increased daytime frequency, a history of cystitis and infrequent bowel habits were not related to MNE, but were significantly related to ES. The prevalence of OAB was 17.8%. Children with a history of cystitis had a significantly higher rate of OAB than children without it.
  
  
  CONCLUSIONS
  Overall, NE and OAB were detected in 5.9% and 17.8% of primary schoolchildren, respectively. The link between NE and OAB symptoms, urinary tract infections and constipation deserves more attention.
authors.affiliation: Department of Urology, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan. urokajiwara@yahoo.co.jp
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kajiwara
authors.forename: Katsumi
authors.initials: K
authors.lastname: Inoue
authors.forename: Masao
authors.initials: M
authors.lastname: Kato
authors.forename: Akihiro
authors.initials: A
authors.lastname: Usui
authors.forename: Makoto
authors.initials: M
authors.lastname: Kurihara
authors.forename: Tsuguru
authors.initials: T
authors.lastname: Usui
mesh_terms: D002648:Child; D004775:Enuresis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D011795:Surveys and Questionnaires; D014549:Urinary Incontinence / Q000453:epidemiology*