Is there a preference for different ways of performing faecal occult blood tests?

Abstract

Low compliance with faecal occult blood screening reduces the power of clinical trials, potential benefit, and efficiency. It has been proposed that the faecal manipulation required to perform conventional guaiac based tests may be an important factor in low compliance. The aim of this study was to evaluate whether use of a new method (vehicle) of stool collection for the faecal occult blood guaiac test would be preferred to the established standard. A novel self-interpreted test, Early Detector (ED), requires the subject to apply a guaiac/peroxide spray to a stool sample collected simply by wiping the anus with a specimen pad. To determine whether this method would be preferred to the stool manipulation required by Haemoccult (HO) and to compare test validity, employees at a London company were invited to use both tests. Eight-hundred and fifty-seven subjects were shown both tests. Before use, 48% indicated a preference for the method of Early Detector; 24% chose Haemoccult (p less than 0.001), while 28% indicated no immediate preference. Seven-hundred and one performed both tests. After use, 74% preferred ED; 5% preferred HO (p less than 0.001); 21% had no preference (NP). The preference for the ED test method was consistent by sex categories, age groups and occupational class. Logistics, aesthetics, and immediacy of results were the main reasons indicated for choosing ED. Whether the preference for ED could result in higher compliance remains to be proven. Its high positivity (14%), however, would preclude its use as a sole test to determine the need for endoscopic and/or radiologic investigation in the screened patient.