Prescreening evaluation of a brush-based faecal immunochemical test for haemoglobin

J Med Screen. 2003;10(3):123-8. doi: 10.1177/096914130301000305.


Objectives: To undertake a prescreening evaluation of a new brush-based faecal immunochemical test for haemoglobin, relative to a traditional spatula-sampling immunochemical test.

Setting: Patients aged between 24 and 90 years, scheduled to undergo diagnostic colonoscopy in two major urban hospitals, for a range of clinical indications.

Design: Patients sampled three stools using a spatula for the reference FlexSure OBT test and two stools using a brush for the InSure test; order of sampling was randomised. Faecal haemoglobin was quantified by a modified InSure in a subset of patients to determine whether brush-sampling allowed discrimination between groups.

Main outcome measures: Sensitivity for cancer or adenoma; false-positive rate in normals. Faecal haemoglobin levels. Preference for sampling method.

Results: InSure and FlexSure OBT did not differ in their sensitivities for cancer (27/36, 75% vs 29/36, 80.5%, respectively), adenomas >or= 10 mm (12/29, 41.4% vs 13/29, 44.8%) or adenomas <10 mm (each 8/56, 14.3%). Likewise, false-positive rates in normals were similar: 4/179 (2.2%) and 5/179 (2.8%) respectively (specificities of 97.8% and 97.2%, respectively). Levels of faecal haemoglobin were highest in those with cancers; those with adenomas had intermediate levels which were also significantly higher than those in normals. The brush sampling method was preferred by 38/46 (82.6%), while 4/46 (8.7%) preferred the spatula (p<0.00001).

Conclusions: InSure is as sensitive and specific as FlexSure OBT for faecal haemoglobin. The novel stool-sampling method of InSure allows discrimination between normals and classes of neoplasia, and is highly preferred. The brush-sampling faecal immunochemical test InSure should now be evaluated in a screening population.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / etiology
  • Adenoma / pathology
  • Adult
  • Aged
  • Colonoscopy
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / etiology
  • Colorectal Neoplasms / pathology
  • Diverticulosis, Colonic / pathology
  • False Positive Reactions
  • Feces / chemistry
  • Female
  • Hemoglobins / analysis*
  • Hemorrhoids / pathology
  • Humans
  • Immunologic Tests / instrumentation
  • Immunologic Tests / methods*
  • Male
  • Mass Screening / methods*
  • Mass Screening / trends
  • Middle Aged
  • Occult Blood*
  • Patient Participation
  • Reagent Kits, Diagnostic*
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Hemoglobins
  • Reagent Kits, Diagnostic