Voided volume < 150 mL on initial uroflowmetry in men with storage symptoms: Is it an unreliable test result or a sign of severe storage symptoms?

Abstract

Purpose To assess the utility of voided volume on initial uroflowmetry in predicting symptom severity in men with storage symptoms. In addition, we assessed the probability that men would show a voided volume of 150 mL on uroflowmetry if the examination is repeated. Methods Between 2016 and 2017, 352 men with storage symptoms were enrolled in the study. The patients completed the frequency–volume chart and were divided into four groups based on the voided volume. A multivariate analysis was performed to determine the variables affecting voided volume. Results The VV was < 68.8 mL in 88 patients (25.0%), 68.9–150 in 89 (25.3%), 150–250 in 87 (24.7%), and 250 in 88 (25.0%) patients. Although the International Prostate Symptom Score did not differ among the groups, the storage subscore was significantly higher in patients with decreased voided volume (p = 0.010). The total number of voids was greater in patients with decreased voided volume (p < 0.001), as was the number of nocturnal voids (p = 0.007). The maximum voided volume (p < 0.001) and 24-h urine output (p = 0.003) decreased as voided volume decreased. The proportions of patients with a mean daytime urine output 150 mL were 30.1%, 43.0%, 64.7%, and 66.7% in each group, respectively (p < 0.001). Older age and decreased maximum voided volume significantly affected the voided volume on initial uroflowmetry. Conclusions A decreased voided volume on initial uroflowmetry may be a sign of severe storage symptoms in men. This finding is related to older age and decreased functional capacity. In these patients, it is better to perform a careful clinical assessment to diagnose and treat overactive bladder.