To evaluate the prevalence, incidence, remission and persistence of overactive bladder (OAB) in male community residents aged 40 years and above.

This was a three-year longitudinal cohort study.  From January 2012 to December 2012, community residents aged 40 years and above, living in the west and south area of central Taiwan were invited to participate in this study.  A structured questionnaire containing groups of different questionnaires including the Overactive Bladder Symptom Score (OABSS) questionnaire was translated into a Chinese version and each one was validated separately.  A trained research assistant interviewed the participants and assisted in filling in the questionnaires. The same questionnaire was sent to all community residents who responded to the first-year questionnaire at a yearly interval for two more consecutive years.  At the end of the third year, data were analyzed to obtain the incidence, persistence, spontaneous remission and relapse of OAB. Overactive bladder was defined as total OABSS score ≧4 and urgency score≧2.  Multivariable logistic regression analysis was performed to consider the effect of all potential risk factors (Age≧60, BMI≧25, diabetes mellitus, smoking, history of urolithiasis, history of urological surgery, low yearly income, low education level) associated with OAB.  In this report, our emphasis was the results for male residents.

Nine hundred and forty-two male community residents aged 40 years and above completed the questionnaires in the 1st year survey to form the baseline cohort. Mean ages were 63.1 ±12.3 years in men with OAB, and 55.9 ±10.4 years in men without OAB (p<0.001). The prevalence of OAB was 15% (141/942). The prevalence increased with age when stratified into different age cohorts    ( 40-49;7%, 50-59;12.7%, 60-69;18.1%, ≧70;32%, p <0.001). At the end of third year, 800 (84.9%) male residents were successfully followed-up and completed all the questionnaires for 3 consecutive years. The second- and third-year incidence rates of OAB were 10% (69/691) and 6.2% (42/674) respectively(figure 1). The remission rates were 47.7% (52/109) and 46% (58/126) respectively. Twelve (23.1%) male residents reported relapse of OAB in the third year. The two-year OAB persistence rate was 30.3% (33/109). Age≧60 (OR, 2.58; 95% CI, 1.62- 4.11) was the risk factor for OAB.

The prevalence and yearly incidence of OAB are high in male community residents aged ≧ 40 years in the central area of Taiwan. Medical or surgical interventions for these residents were not evaluated in this study and yet the OAB persistence rate was 30.3%.

Age is an important risk factor for OAB, and since the elderly population in Taiwan is growing, our study provides important information for the modification of health care policies in the future.