The prevalence and risk factors of overactive bladder in Korean children: A comparative analysis according to definition

Purpose: We wanted to estimate the prevalence and risk factors of overactive bladder (OAB) in Korean children who were 5-13 years of age, according to the definition of OAB. Materials and Methods: A randomly selected cross-sectional study was conducted on 26 kindergartens and 27 elementary schools nationwide in Korea. There were 19,240 children; a parent was asked to complete the questionnaires, which included items about OAB and the children's voiding and defecating habits. OAB was defined as urgency with or without urge incontinence, and usually with an increased daytime frequency and nocturia (ICCS 2006, group A) or an increased daytime frequency (>8 times/day) and/or urge urinary incontinence with or without urgency (group B); its prevalence and associated factors were investigated. Results: The response rate for the questionnaires was 85.84%. The overall prevalence of OAB was 16.59% (group A) and 18.79% (group B). For groups A and B, the prevalence of OAB decreased with age from 22.89% to 12.16% and from 40.44% to 9.60%, respectively (p=0.0001). The overall rate of wet and dry OAB was 26.97% and 73.03%, respectively. Compared to the normal group, the children with OAB had a higher prevalence of nocturnal enuresis (NE), constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control in both groups A and B (p < 0.05). The rate of increased daytime frequency and urge incontinence were 3.69% and 2.31% (p=0.009), and 26.97% and 14.78% (p=0.0001) in group A and for the non-OAB children, respectively; their prevalence in group A decreased with age from 5.04% to 3.06% and from 45.74% to 18.50%, respectively (p=0.0001). Conclusions: The overall prevalence of OAB in group A for Korean children 5-13 years of age was similar to that in group B. However, the range of prevalence in group B was much more variable than that in group A. NE, constipation, fecal incontinence, a history of urinary tract infection and delayed bladder control may be risk factors for OAB in children.