Convenience voids: an important new factor in urinary frequency volume chart analysis.

PURPOSE

We assessed the impact of convenience voids (CVs) on urinary frequency volume chart (FVC) analysis.

MATERIALS AND METHODS

A total of 53 healthy volunteers completed a FVC for 1 week, highlighting as CVs samples when there was no sensation of bladder fullness, but rather a social reason to pass urine instead.

RESULTS

Of the volunteers 72% had at least 1 CV during the week. Removing the CVs from analysis resulted in an increase of 17 ml in average mean individual voided volume from 308 to 325 ml (p <0.001). The average mean interval between voids increased by 11 minutes from 4 hours 34 minutes to 4 hours 45 minutes (p <0.001).

CONCLUSIONS

Convenience voids have a small but significant effect on parameters analyzed on FVCs. They should be considered for inclusion in the FVCs used in research when changes in voided volume are being investigated.