Pad Count is a Poor Measure of the Severity of Urinary Incontinence

Abstract

We analyzed the correlation between pad use, as determined by objective pad count, and the severity of urinary incontinence, as measured by pad weight. We performed a retrospective study of consecutive incontinent patients who wore pads on a daily basis and were instructed to complete a 24-hour pad test. They were told to use the usual pads, change them as usual and place each in a separate plastic bag the day before the scheduled appointment. All pads were weighed and total urine loss was calculated by subtracting dry pad weight from wet pad weight, assuming that a 1 gm weight increase was equivalent to 1 ml of urine loss. The number of pads was correlated to pad weight using the Spearman rank correlation coefficient due to the nonparametric nature of the data. The 116 patients included 51 men 39 to 89 years old (mean age 66) and 65 women 27 to 95 years old (mean age 72). When comparing the number of pads used to the gm of urine lost, the Spearman ρ was 0.26 (p=0.005) in the total cohort, and 0.40 and 0.26 (each p<0.05) in males and females, respectively. There was little correlation between the number of pads used and the severity of urinary incontinence (r=0.26). These data suggest that pad count should not be used as an objective measure of incontinence severity. Instead, pad weight on a 24-hour pad test should be used.