Pooled data from seven randomized placebo-controlled trials were analysed to evaluate relationships between baseline body mass index (BMI), gender or age and the efficacy/tolerability of solifenacin (5 - 10 mg daily) in patients with overactive bladder (OAB). Changes in efficacy variables from baseline to 12 weeks were compared in patients with symptoms at baseline between solifenacin-treated and placebo-treated groups. Normalization rates were calculated (no more than eight micturitions in 24 h, no more than one episode of nocturia per night, zero values for other variables over 24 h). Treatment-emergent adverse events (TEAEs) were recorded. The baseline incidence of incontinence and urgency incontinence increased with increasing BMI and age; relatively more women than men were incontinent. The baseline incidence of urgency was similar between genders and among age groups, but tended to increase with increasing BMI. The baseline frequencies of micturition and nocturia were similar in all BMI categories, between genders and in all age groups. The results from this meta-analysis of an integrated database of data from trials investigating solifenacin showed that solifenacin was more efficacious than placebo for all OAB symptoms across all BMI and age categories, and between genders. Normalization rates for micturition frequency, incontinence and urgency were greater in patients receiving solifenacin than in those receiving placebo across all categories. The overall incidence of TEAEs was higher in patients receiving solifenacin than in those receiving placebo; solifenacin was generally well tolerated in both groups. The overall frequency of TEAEs for solifenacin and placebo was slightly higher in women than in men and in older than in younger patients. The most commonly reported TEAEs were dry mouth and constipation. Regardless of BMI, gender or age, all patients with OAB can be considered candidates for solifenacin treatment.