Inadequate repeatability of the one‐hour pad test: the need for a new incontinence outcome measure

Abstract

Objective To assess the reproducibility of two one-hour pad tests performed within one week using serial ultrasound scanning to obtain identical bladder volumes, and to measure the effect of patient anxiety upon test reproducibility.Design Prospective observational study. Setting Tertiary urogynaecological unit.Sample Fifty-six incontinent women undergoing 112 pad tests. Method Two one-hour pad tests were performed with natural diuresis one week apart prior to treatment. At the second test, serial ultrasound scans were performed until bladder volume reached that of the ®rst test, followed by identical provocation.Main outcome measures One-hour pad loss, bladder volumes (Vol 1 , Vol 2 ), anxiety VAS questionnaire.Results Despite serial scanning, bladder volumes differed signi®cantly. Median volume before second pad test was 541 mL, compared with 433 mls before ®rst test (P , 0.001). The second pad test was also signi®cantly larger than ®rst (median 16g vs 4g, P 0.017), and 13/56 (23%) women were dry on the ®rst test but incontinent on the second. In 26 women (46%) both bladder volumes were similar, but the second pad loss was still signi®cantly greater (median 14g vs 4g, P 0.037). The mean difference between tests was 10g and the limits of agreement were wide (ranging from ±44 to 166 g difference for the test result). Women were more anxious about leaking during the ®rst test (Median VAS during the ®rst test was 2.8cm, compared with 0.6cm during the second test, P 0.008). 42.5% found the second test to be more typical. ConclusionIn women with similar bladder volumes, the test±retest reliability of the one-hour pad test was judged to be clinically inadequate, as the ®rst and second pad test could differ by ±44 to 166g. Lower anxiety levels at the second test may account for this ®nding. The one-hour pad test is a useful baseline measure of incontinence, but the poor repeatability suggests that is not an optimal measure of post-treatment change.

Comparison of the ICIQ-SF and 24-hour pad test with other measures for evaluating the severity of urodynamic stress incontinence

“…It may be performed over a variety of time intervals. Whereas the volume of urinary loss assessed by the 24-h pad test has been consistently demonstrated by various authors to be reproducible, the repeatability of the 1-h pad test has been questioned [2,3,4,5,6,7].…”

Lower urinary tract symptoms after total and subtotal hysterectomy: results of a randomized controlled trial

“…The criterion validity of the questionnaire was not studied as we had difficulties finding the ''gold standard'' against which the results of the questionnaire could be tested. No obvious and valid method existed against which urinary incontinence could be measured [30][31][32][33]. A possible way to further validate our question could be to have our patients complete a 1-week voiding diary [34].…”

The repeatability of the 24-hour pad test

“…In comparison, there has been consistent criticism of the 1-hour pad test in the recent literature [5,6,7].…”

“…The 1-hour pad test has been standardised [4], requiring women to perform a set of activities to provoke leakage in the laboratory. However, the repeatability of the test has been discredited [5,6,7]. Furthermore, the responsiveness of the 1-hour pad test to changes has also been questioned [8].…”