Pad weighing tests: the best way to quantify urine loss in patients with incontinence.

This article reviews the literature on pad weighing tests composed to measure urinary incontinence. The tests can be divided into short-term tests (one to two hours) performed in a clinic or laboratory, or long-term tests (12 to 48 hours) performed by the patient at home. The short-term tests, apart from practical disadvantages, have low negative predictive value and require retrograde filling of the bladder to reach acceptable reproducibility. The long-term tests have practical advantages, better sensitivity and acceptable reproducibility. Pad weighing tests have no value for the purpose of differential diagnosis. The validity of the long-term test as a measure of the symptom of urinary incontinence is obvious whereas it is unclear what the short-term test measures.