Alternative diagnoses and demographics associated with a raised quantitative faecal immunochemical test in symptomatic patients

Johnstone, M. S. et al. (2022) Alternative diagnoses and demographics associated with a raised quantitative faecal immunochemical test in symptomatic patients. Annals of Clinical Biochemistry, 59(4), pp. 277-287. (doi: 10.1177/00045632221076771) (PMID:35044264) (PMCID:PMC9280700)

Abstract

Background The faecal immunochemical test (FIT) has proven utility for colorectal cancer detection in symptomatic patients. However, most patients with a raised faecal haemoglobin (f-Hb) do not have colorectal cancer. We investigated alternative diagnoses and demographics associated with a raised f-Hb in symptomatic patients. Methods A retrospective, observational study was performed of patients with FIT submitted between August 2018 to January 2019 in NHS Greater Glasgow and Clyde followed by colonoscopy. Colonoscopy/ pathology reports were searched for alternative diagnoses. Covariables were compared using the χ2 test. Multivariate binary logistic regression identified independent predictors of a raised f-Hb. Results 1272 patients were included. In addition to colorectal cancer (odds ratio (OR) 9.27 (95% confidence interval (CI): 3.61-23.83;p<0.001)), older age (OR 1.52 (95% CI: 1.00-2.32;p=0.05)), deprivation (OR 1.54 (95% CI: 1.21-1.94;p<0.001)), oral anticoagulants (OR 1.78 (95% CI: 1.01-3.15;p=0.046)), rectal bleeding (OR 1.47 (95% CI: 1.15-1.88;p=0.002)), advanced adenoma (OR 7.52 (95% CI: 3.90-14.49;p<0.001)), non-advanced polyps (OR 1.78 (95% CI: 1.33-2.38;p<0.001)) and inflammatory bowel disease (IBD) (OR 4.19 (95% CI: 2.17-8.07;p<0.001)) independently predicted raised f-Hb. Deprivation (Scottish Index of Multiple Deprivation (SIMD) 1-2: OR 2.13 (95% CI: 1.38-3.29; p=0.001)) independently predicted a raised f-Hb in patients with no pathology found at colonoscopy. Conclusions An elevated f-Hb is independently associated with older age, deprivation, anticoagulants, rectal bleeding, advanced adenoma, non-advanced polyps and IBD in symptomatic patients. Deprivation is associated with a raised f-Hb in the absence of pathology. This must be considered when utilising FIT in symptomatic patients.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mansouri, Mr David and Johnstone, Mr Mark and Winter, Dr Jack and Witherspoon, Mr Paul and McSorley, Dr Stephen and Smith, Ms Karen
• Authors: Johnstone, M. S., Miller, G., Pang, G., Burton, P., Kouronis, G., Winter, J., Crighton, E., Mansouri, D., Witherspoon, P., Smith, K., and McSorley, S. T.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Annals of Clinical Biochemistry
• Publisher: SAGE Publications
• ISSN: 0004-5632
• ISSN (Online): 1758-1001
• Published Online: 19 January 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Annals of Clinical Biochemistry 59(4): 277-287
• Publisher Policy: Reproduced in accordance with the publisher copyright policy