Table 2 Non-inferiority margins and sample size requirements for 5-yearly surveillance (vs. 10-yearly surveillance) of low-risk adenoma patients
From: Evidence-based sizing of non-inferiority trials using decision models
Strategy | 10y cumulative incidence | Life-years (per 1000 pt) | QALYs lost to surveillance (per 1000 pt) | QALYs lost to surveillance complications (per 1000 pt) | QALYs lost to CRC treatment (per 1000 pt) | QALYs (per 1000 pt) | Required sample size |
|---|---|---|---|---|---|---|---|
Non-inferiority based on effectiveness and average disutilities (base case) – 3.1 days lost per colonoscopy | |||||||
5-yearly surveillance | 1.0% | 22,424 | 26.3 | 0.3 | 54.1 | 22,343 | 19,234 |
10-yearly surveillance | 1.42% | 22,415 | 18.1 | 0.2 | 53.5 | 22,343 | |
Non-inferiority based on cost-effectiveness using threshold of €20,000 per QALY gained and base case disutilities (3.1 days lost per colonoscopy) | |||||||
5-yearly surveillance | 1.0% | 22,424 | 26.3 | 0.3 | 54.1 | 22,343 | 8826 |
10-yearly surveillance | 1.62% | 22,408 | 18.2 | 0.2 | 59.2 | 22,331 | |
Non-inferiority based on 80% of base disutilities (2.5 days lost per colonoscopy) | |||||||
5-yearly surveillance | 1.0% | 22,424 | 21.0 | 0.3 | 54.1 | 22,348 | 21,206 |
10-yearly surveillance | 1.40% | 22,416 | 14.5 | 0.2 | 52.8 | 22,348 | |
Non-inferiority based on 120% of base disutilties (3.7 days lost per colonoscopy) | |||||||
5-yearly surveillance | 1.0% | 22,424 | 31.5 | 0.3 | 54.1 | 22,338 | 16,754 |
10-yearly surveillance | 1.45% | 22,414 | 21.7 | 0.2 | 54.2 | 22,338 | |