An epidemiological survey of overactive bladder symptoms in Japan

OBJECTIVE To report an epidemiological survey of lower urinary tract symptoms (LUTS) to determine the prevalence of overactive bladder (OAB) symptoms (defined as a symptom complex of daily urinary frequency of eight or more times and urgency once or more per week) in Japan. SUBJECTS AND METHODS A self-administered questionnaire was mailed to 10 096 Japanese men and women aged >= 40 years selected by a two-stage randomized process. Survey questions, developed by members of the Japan Neurogenic Bladder Society Committee, covered four areas: demographic characteristics, LUTS, health-related quality of life (HRQoL), and hospital attendance. RESULTS The responses from 4570 respondents (mean age 61 years) were analysed. The estimated prevalence of OAB was 12.4% (men 14%, women 11%). Prevalence rates for OAB with and without urgency incontinence (one or more episode/week) were 6.4% and 6.0%, respectively. Prevalence rates increased with age; 5% of respondents aged 40-49 and 37% of those aged >= 80 years had OAB. HRQoL was compromised in 53% of respondents with OAB symptoms, specifically emotions (42%), sleep/vitality (37%), physical limitation (34%), role limitation (29%), and social limitation (22%). Among those whose HRQoL was affected, 23% (men 36%, women 8%) had visited a medical institution because of their urinary problems. CONCLUSION The results from this survey indicate that the prevalence of OAB was high and increased with age, but the rate of hospital attendance was low. Public awareness of OAB should be increased so that there can be optimum management of this condition.