Cost savings of removing diminutive polyps without laboratory histology

Objectives:

Decennial colonoscopy with polypectomy is an effective screening strategy which may be unaffordable to a segment of the population. Immediate endoscopic assessment of colorectal polyp histology is increasingly accurate. Approximately 80% of polyps are diminutive (< 6mm), rarely containing cancer. Histologies of such polyps only guide subsequent colonoscopy intervals. We explored the possibility that immediate assessment vs. laboratory histology for diminutive polyps could be a cost-effective alternative.

Methods:

From a database of 10,060 consecutive colonoscopies, probabilities and characteristics of polyps were retrieved to parameterize a decision tree model. Four groups of patients were characterized by number, sizes, and types of polyp(s) present. In the model, sensitivity and specificity of gastroenterologist and laboratory assessments were specified, and sensitivity analysis was used to evaluate the uncertainty in these values.

Results:

Database analysis found 4474 patients (44.5%) had one or more diminutive polyps. At $89 per specimen, the model predicted $180 could be saved for each such patient. Of 2589 patients with adenomas, 5% would be mislabeled using immediate assessment vs. 3% using pathology. Only 9% of patients with diminutive polyps would be scheduled for follow-up at a non-recommended interval; most of these would be patients without adenomas who would be scheduled for a 5-year, rather than 10-year follow up. Less than 1 in 1100 patients with a diminutive polyp would have had an undetected, although removed, cancer.

Conclusion:

With continual improvement in the ability to assess pathology immediately, a screening strategy with immediate assessment could make colonoscopy more affordable and accessible.