Accuracy of faecal occult blood test and Helicobacter pylori stool antigen test for detection of upper gastrointestinal lesions.
OBJECTIVE
Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions.


DESIGN
Cross-sectional design.


SETTING
Hospital-based and community-based screening settings.


PARTICIPANTS
A hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings.


INTERVENTIONS
Three types of stool tests with bidirectional endoscopy as the reference standard.


OUTCOMES
Sensitivity, specificity and positive and negative likelihood ratios.


RESULTS
For detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values.


CONCLUSIONS
The H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper gastrointestinal lesions in a population with high prevalence of H pylori infection and upper gastrointestinal lesions. It is applicable to add the H pylori antigen test to the immunochemical test for pan detection.


TRIAL REGISTRATION
NCT01341197 (ClinicalTrial.gov).
['Lee|Yi-Chia|YC|', 'Chiu|Han-Mo|HM|', 'Chiang|Tsung-Hsien|TH|', 'Yen|Amy Ming-Fang|AM|', 'Chiu|Sherry Yueh-Hsia|SY|', 'Chen|Sam Li-Sheng|SL|', 'Fann|Jean Ching-Yuan|JC|', 'Yeh|Yen-Po|YP|', 'Liao|Chao-Sheng|CS|', 'Hu|Tsung-Hui|TH|', 'Tu|Chia-Hung|CH|', 'Tseng|Ping-Huei|PH|', 'Chen|Chien-Chuan|CC|', 'Chen|Mei-Jyh|MJ|', 'Liou|Jyh-Ming|JM|', 'Liao|Wei-Chih|WC|', 'Lai|Yo-Ping|YP|', 'Wang|Chen-Ping|CP|', 'Ko|Jenq-Yuh|JY|', 'Wang|Hsiu-Po|HP|', 'Chiang|Hung|H|', 'Lin|Jaw-Town|JT|', 'Chen|Hsiu-Hsi|HH|', 'Wu|Ming-Shiang|MS|']
GASTROENTEROLOGY