Population based randomized study of uptake and yield of screening by flexible sigmoidoscopy compared with screening by faecal occult blood testing.
OBJECTIVE
To compare the feasibility of mass screening by flexible sigmoidoscopy with screening by faecal occult blood testing (Haemoccult) and both tests combined.


METHODS
Patients were randomised to screening by flexible sigmoidoscopy, faecal blood testing, or both tests. The flexible sigmoidoscopy examinations were performed by a general practitioner.


METHODS
General practice.


METHODS
3744 patients aged 50-75 years.


METHODS
Uptake, positive results, detection of neoplasia, complications, and recall for diagnostic colonoscopy.


RESULTS
Uptake was significantly higher in the flexible sigmoidoscopy group (46.6%) than in the faecal blood test group (31.6%; P<0.001) or than in the group having both tests (30.1%; P<0.001). Telephone reminders increased uptake of sigmoidoscopy to 61.8%. In total, 1116 sigmoidoscopy examinations were performed without major complication. Polyps were found in 19. 3% (95% confidence interval 17.0% to 21.6%) but only 6.8% (5.3% to 8. 3%) had adenomas and 2.4% (1.5% to 3.3%) "high risk" adenomas. Cancer was detected in four subjects. The faecal blood test yielded positive results in 0.8% (0.2% to 1.4%) but missed at least one cancer and 30 cases of adenoma which were found by sigmoidoscopy in the combined group. Use of histological criteria-shown elsewhere to correlate with future risk of colorectal cancer-to select "positive" patients could reduce recall for diagnostic colonoscopy from about 20% to less than 5%.


CONCLUSIONS
Some of the predicted obstacles to screening with flexible sigmoidoscopy are surmountable. Clear evidence relating to efficacy will be obtained only from a randomised controlled trial.
ICRF Colorectal Cancer Unit, St Mark's Hospital, Northwick Park, Middlesex HA1 3UJ.
J E
JE
Verne
R
R
Aubrey
S B
SB
Love
I C
IC
Talbot
J M
JM
Northover
D000368:Aged; D004739:England; D005194:Family Practice; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000517:prevention & control; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data*; D008875:Middle Aged; D009780:Occult Blood; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D012004:Rectal Neoplasms / Q000517:prevention & control*; D012680:Sensitivity and Specificity; D012811:Sigmoid Neoplasms / Q000517:prevention & control*; D012812:Sigmoidoscopy / Q000379:methods / Q000706:statistics & numerical data