Factors that influence the decision to do an adequate evaluation of a patient with a positive stool for occult blood.

Objective: The factors that influence the decision to do an adequate evaluation for a positive test for fecal occult blood in a middle-aged or elderly patient are largely unknown. Our study was undertaken to determine whether factors such as the number of positive Hemoccult II card windows, age, gender, family history of colon cancer, the patient's concern that he or she might have colon cancer, or history of rectal bleeding influence the evaluation performed.

Method: A mass screening program for colon cancer was performed using unrehydrated Hemoccult II cards in the Boston area.

Results: Among the 23,593 Hemoccult II cards returned to Beth Israel Deaconess Medical Center, cards from 1,112 patients (4.7%) were found to be positive for one or more of the six possible card windows. Ninety percent, or 940 patients, over 40 yr of age had follow-up information available. As the number of positive windows increased from one to four, there was a significant trend (p < 0.001) for the adequacy of the evaluation to increase. Family history (p = 0.044) and a patient's worry that he or she might have colon cancer (p = 0.003) significantly improved a patient's chance for an adequate evaluation.

Conclusions: Hemoccult testing is not followed by an adequate evaluation in a significant proportion of patients. Our study points out for the first time that the number of positive Hemoccult windows significantly influences the decision-making.