The frequency/volume chart as a differential diagnostic tool in female urinary incontinence

Abstract

The objective of this study was to investigate the differential diagnostic capacity of the frequency/volume chart. Thus the readings of a 48-hour frequency/volume chart were compared to the urodynamic findings in 62 motor urgency incontinent women and 80 genuine stress incontinent women. Applying logistic regression to the parameters of the frequency/volume chart, with the urodynamic diagnosis as the gold standard, the effectiveness of different parameters and parameter combinations to differentiate motor urgency incontinence from genuine stress incontinence could be estimated. The best differentiating single parameters of the chart were the frequency of micturition and the mean voided volume. A combination of two parameters improved differentiation, with the frequency of micturition in combination with some measure of variability, e.g. the range of voided volumes, being the best. From these results, plots indicating the probability of a diagnosis could be calculated. It is concluded that the frequency/volume chart has differential diagnostic properties. A new feature of the chart, the variability of voided volumes, is introduced and shown to improve the differentiating capacity.