Pad test by mail for home evaluation of urinary incontinence

To present a simple, cost-effective, and convenient method of home pad test using the mail system and evaluating change in pad weight over time.

A series of nine kinds of commonly available commercial brands of urinary incontinence pads ranging from thin liners less than 10 g in dry weight to large diapers weighing over 100 g each were assembled. Two or three of each variety were individually weighed on an OHAUS LS2000 Portable Standard scale accurate to +/- 1 g. The pads were then wet uniformly with 20 cc of saline, placed individually in sealable plastic bags, sealed, and reweighed. Random groups of three pads were mailed by standard 1st class mail to the Urocenter of New York. The sealed pads were reweighed at 8 and 14 days from the original wetting. Concurrently, ten incontinence pads soiled with urine were similarly examined to confirm that there would be no detectable difference between urine and saline for the purpose of the study. In the second part of the study, 20 pads of the same type (13 inch-long pads with absorbent gel) were divided into 4 groups of 5 pads; each group was uniformly wet with 5, 10, 20, or 50 g of saline. These pads were mailed and reweighed at 7 and 14 days from the initial wetting.

Twenty-four pads were used in the first part of the study. The dry weights of 22/24 (92%) of the pads were within 2 g of the average weight for their brand. At the first reweighing, 22 pads (92%) weighed within 2 g of their initial wet weights (Fig. 1). Only two pads on day 8 differed substantially from their initial weights: one pad appeared to have lost 4 g and another one 9 g. On day 14, 23/24 pads remained within 1 g of their day 8 weight and 1 differed by 2 g, and the total weight of the 24 pads on day 14 was only 4 g different from their initial weight (P = 0.71, Fig. 1). The soiled pads exhibited weight changes that were indistinguishable from the saline pads. The average cost of mailing the pads by 1st class mail was $4 and the average length of time in the mail was 5 days +/- 1 day. In the second part of the study, 18/20 pads had lost less than 1 g at 1 week, and at 2 weeks, 19/20 had lost less than 2 g when compared to their initial weights (Fig. 2). One pad had lost 3 g. Pads in the low volume groups (5 and 10 g) lost an average of 1.4 and 1.2 g, respectively, while pads in the high volume groups (20, 50 g) lost an average of 1.8 and 2 g at 2 weeks.

Dry pads of any single brand have a relatively standard weight that varies insignificantly between pads. Up to 2 weeks of delay in the weighing of individually sealed pads does not significantly affect the clinical measurement of weight at a variety of low (5 g) or high (50 g) volumes of simulated incontinence. Home pad test using the mail system is a feasible, inexpensive, and clinically accurate method of evaluating incontinence. Patients can be instructed in techniques for home pad test, allowing for greater compliance, and convenience for both physicians and patients.