Uroflow measurements in healthy female volunteers.

OBJECTIVE: : There is not currently a standard definition of "normal" for uroflowmetry parameters, particularly with respect to spontaneous voids or multiple repeated measurements within an individual. Our study aimed to describe uroflow parameters for "normal" in a group of healthy women based on repeated measurements. METHODS: : Spontaneous voids of twelve healthy women were recorded over two weeks. Additionally, one prompted void per subject was recorded. Prompted voids were compared to the subjects' spontaneous voids. These voids were also compared to those of patients evaluated for urinary incontinence. Groups were compared using paired t tests. RESULTS: : The mean voided volume was 306 ml and the mean maximum flow rate was 49 ml/s. The prompted voids were lower in volume, maximum flow, and duration than spontaneous voids. When corrected for volume, these differences were not significant. Maximum flow rates in patients evaluated for urinary incontinence were lower than those of volunteers. CONCLUSIONS: : Uroflowmetry parameters vary widely between and within healthy volunteers. Prompted voids are representative of spontaneous voids. Maximum flow rates of patients evaluated for urinary incontinence were lower than those of volunteers. In a group of healthy volunteers voiding in a private, spontaneous setting, a maximum flow rate of lower than 17 ml/s (2 SDs below the mean) might be considered abnormally low.