Expanded paper towel test: an objective test of urine loss for stress incontinence

To investigate the repeatability of a short stress test of coughing and jumping (the expanded Paper Towel Test (PTT)) to quantify urine loss in stress incontinent adult women.

In the laboratory, the reliability of two methods of measuring the size of the wet area, produced by a typical volume of water titrated onto paper towel was investigated and some absorbency properties of the brand of towel used were quantified. Thirty one women performed a provocative coughing and jumping test on consecutive days using a "perineal pad" of paper towel. The repeatability coefficient was calculated.

The provocative test was repeatable to within 2.8 ml of urine loss, but with the exclusion of one anomalous result, the repeatability improved to lie within 1 ml. The coefficient of variation (CV) for the between-method differences (computer scanning and graph paper) was 1.27%. A volume of 1 ml of water produced a wet area of 25.7 cm2. The range of measurable areas corresponded to volumes of 0.005-8 ml. Standardization of method is required because the size of the wet area differed by manufacturer of paper towel (P < 0.01, two products compared) and with time elapsed since titration (P < 0.01).

The "expanded PTT" is a simple tool for quantification of urine loss (0.005-8 ml) in women to 72 years with stress incontinence. With a suggested modification, it should prove reliable for detection of between-visit differences of 1 ml. The reliability of the test is dependent upon the use of standard protocol and paper towel with known volume-area ratio. To improve clinical diagnosis, it can also be used with any brand of paper towel to confirm the sign of stress incontinence on exertion.