Stool DNA Analysis is Cost-Effective for Colorectal Cancer Surveillance in Patients With Ulcerative Colitis

Abstract

Background & aims: Patients with chronic ulcerative colitis are at increased risk for colorectal neoplasia (CRN). Surveillance by white-light endoscopy (WLE) or chromoendoscopy may reduce risk of CRN, but these strategies are underused. Analysis of DNA from stool samples (sDNA) can detect CRN with high levels of sensitivity, but it is not clear if this approach is cost-effective. We simulated these strategies for CRN detection to determine which approach is most cost-effective.

Methods: We adapted a previously published Markov model to simulate the clinical course of chronic ulcerative colitis, the incidence of cancer or dysplasia, and costs and benefits of care with 4 surveillance strategies: (1) analysis of sDNA and diagnostic chromoendoscopy for patients with positive results, (2) analysis of sDNA with diagnostic WLE for patients with positive results, (3) chromoendoscopy with targeted collection of biopsies, or (4) WLE with random collection of biopsies. Costs were based on 2014 Medicare reimbursement. The primary outcome was the incremental cost-effectiveness ratio (incremental cost/incremental difference in quality-adjusted life-years) compared with no surveillance and a willingness-to-pay threshold of $50,000.

Results: All strategies fell below the willingness-to-pay threshold at 2-year intervals. Incremental cost-effectiveness ratios were $16,362 per quality-adjusted life-year for sDNA analysis with diagnostic chromoendoscopy; $18,643 per quality-adjusted life-year for sDNA analysis with diagnostic WLE; $23,830 per quality-adjusted life-year for chromoendoscopy alone; and $27,907 per quality-adjusted life-year for WLE alone. In sensitivity analyses, sDNA analysis with diagnostic chromoendoscopy was more cost-effective than chromoendoscopy alone, up to a cost of $1135 per sDNA test. sDNA analysis remained cost-effective at all rates of compliance; when combined with diagnostic chromoendoscopy, this approach was preferred over chromoendoscopy alone, when the specificity of the sDNA test for CRN was >65%.

Conclusions: Based on a Markov model, surveillance for CRN is cost-effective for patients with chronic ulcerative colitis. Analysis of sDNA with chromoendoscopies for patients with positive results was more cost-effective than chromoendoscopy or WLE alone.

Keywords: Cost Benefit Analysis; ICER; Inflammatory Bowel Diseases; QALY.

Figure 1

Model health state transition diagram from chronic ulcerative colitis (UC) to dysplasia, colorectal cancer (CRC), surgery or death Adapted from Konijeti GG, Shrime MG, Ananthakrishnan AN, Chan AT. Cost-effectiveness analysis of chromoendoscopy for colorectal cancer surveillance in patients with ulcerative colitis. Gastrointest Endosc. 2014 Mar;79(3):455-65 and used with permission.

Figure 2

Incremental cost-effectiveness ratios for each surveillance strategy at (A) annual, (B) biennial and (C) every 3-years surveillance intervals in comparison to no surveillance, which cost $189,960 for 19.65 quality-adjusted life years (QALY). CE, chromoendoscopy; sDNA, stool DNA; WLE, white light endoscopy

Figure 2

Incremental cost-effectiveness ratios for each surveillance strategy at (A) annual, (B) biennial and (C) every 3-years surveillance intervals in comparison to no surveillance, which cost $189,960 for 19.65 quality-adjusted life years (QALY). CE, chromoendoscopy; sDNA, stool DNA; WLE, white light endoscopy

Figure 2

Incremental cost-effectiveness ratios for each surveillance strategy at (A) annual, (B) biennial and (C) every 3-years surveillance intervals in comparison to no surveillance, which cost $189,960 for 19.65 quality-adjusted life years (QALY). CE, chromoendoscopy; sDNA, stool DNA; WLE, white light endoscopy

Figure 3

(A) Incremental cost-effectiveness ratio (ICER) scatter plot and 95% confidence interval ellipse in relationship to $50,000 willingness to pay threshold (WTP) for stool DNA with diagnostic chromoendoscopy in reference to no surveillance. Quadrants (QI-IV) are defined by cost and effectiveness axes and components (C1-6) define where stool DNA is recommended or not in relationship to WTP. (B) Interpretation key shows that stool DNA with diagnostic chromoendoscopy was the recommended surveillance strategy in the majority (71%) of cohorts in which the full range of model parameters was sampled.

Figure 3

(A) Incremental cost-effectiveness ratio (ICER) scatter plot and 95% confidence interval ellipse in relationship to $50,000 willingness to pay threshold (WTP) for stool DNA with diagnostic chromoendoscopy in reference to no surveillance. Quadrants (QI-IV) are defined by cost and effectiveness axes and components (C1-6) define where stool DNA is recommended or not in relationship to WTP. (B) Interpretation key shows that stool DNA with diagnostic chromoendoscopy was the recommended surveillance strategy in the majority (71%) of cohorts in which the full range of model parameters was sampled.

Figure 4

Acceptability curves for the each of the major input variable categories (A) utilities, (B) costs and (C) probabilities. Probabilities were further examined in smaller clusters of variables at a time (D) which all met base-case expectations.

Figure 4

Acceptability curves for the each of the major input variable categories (A) utilities, (B) costs and (C) probabilities. Probabilities were further examined in smaller clusters of variables at a time (D) which all met base-case expectations.

Figure 4

Acceptability curves for the each of the major input variable categories (A) utilities, (B) costs and (C) probabilities. Probabilities were further examined in smaller clusters of variables at a time (D) which all met base-case expectations.

Figure 4

Acceptability curves for the each of the major input variable categories (A) utilities, (B) costs and (C) probabilities. Probabilities were further examined in smaller clusters of variables at a time (D) which all met base-case expectations.