Development and evaluation of a disposable device for performing simultaneous duplicate bleeding time determinations.

A disposable bleeding time device that provides two simultaneous standardized incisions is described. The mean bleeding time of 47 normal adults was 4.1 min with a 95% range of 2.2--7.0 min. The standard deviation of duplicate bleeding times was 0.7 min, and the day-to-day standard deviation for individuals was 0.9 min. In a double-blind crossover study of 20 normal adults, the mean bleeding time increased from 3.7 to 6.2 min after ingestion of 1 g aspirin. The device is extremely simple to use and is essentially painless. Physical trauma is minimal.