Table 3.
Parameters associated with CRC natural history and screening model
| Mean | Source | |
|---|---|---|
| Screening participation and harm parameters | ||
| FOBT participation for each screening round | 0.54 | NHS BCSP data [25] |
| Proportion completing at least one FOBT screening round | 0.63 | NHS BCSP data [25] |
| FOBT participation for a round for those who comply with at least one FOBT | 0.85 | Calculated from above parameters |
| COL follow-up compliance FOBT screening | 0.79 | NHS BCSP data [25] |
| COL surveillance compliance | 0.83 | NHS BCSP data [25] |
| COL (without polypectomy) perforation rate | 0.0 % | FS UK screening trial data [26] |
| COL (with polypectomy) perforation rate | 0.3 % | Bowel cancer screening pilot 2nd round evaluation [27] |
| COL Probability of death following perforation | 5.2 % | Gatto et al. [28] |
| COL probability of hospitalization for bleeding | 0.3 % | FS UK screening trial data [26] |
| Health-related quality of life parameters | ||
| Utility value cancer free | 0.80 | Ara et al. [29] |
| Utility value CRC | 0.70 | Ara et al. [29] |
| Resource use parameters | ||
| gFOBT mean number of tests completed | 1.08 | Assumption details in [14] |
| COL repeat test rate | 0.07 | NHS BCSP data [25] |
| Cost of gFOBT screen (non-compliers) | £2.03 | Southern Hub screening costings model [14] |
| Cost of gFOBT screen (normal result) | £3.36 | Southern Hub screening costings model [14] |
| Cost of gFOBT screen (positive result) | £11.94 | Southern Hub screening costings model [14] |
| Cost of COL (without polypectomy) | £563 | NHS ref costs, screening centre estimates [14] |
| Cost of COL (with polypectomy) | £563 | NHS ref costs, screening centre estimates [14] |
| Cost of treating bowel perforation (major surgery) | £5,089 | NHS reference costs [14] |
| Cost of admittance for bleeding (overnight stay on medical ward) | £278 | NHS reference costs [14] |
| Pathology cost for adenoma/cancer | £26 | NHS reference costs 08/09, histopathology [14] |
| Cost of treating colorectal cancer, Dukes’ stage A | £1,320–£8,375 | Ranges presented reflect variation according to age at diagnosis. Generated using model from Tappenden [24] |
| Cost of treating colorectal cancer, Dukes’ stage B | £1,479–£8,362 | |
| Cost of treating colorectal cancer, Dukes’ stage C | £1,493–£13,862 | |
| Cost of treating colorectal cancer, Dukes’ stage D | £772–£11,198 | |
| Test characteristics | ||
| gFOBT sensitivity for LR adenomas | 0.01 | Model calibration [11] |
| gFOBT sensitivity for HR adenomas | 0.12 | Model calibration [11] |
| gFOBT sensitivity for CRC | 0.24 | Model calibration [11] |
| gFOBT specificity age 50 | 0.99 | Model calibration [11] |
| gFOBT specificity age 70 | 0.97 | Model calibration [11] |
| COL sensitivity for LR adenomas | 0.77 | Van Rijn et al. [30] |
| COL sensitivity for HR adenomas | 0.98 | Van Rijn et al. [30] |
| COL sensitivity for CRC | 0.98 | Bressler et al. [31] |
| COL specificity | 1.00 | Assumption due to nature of the test |
| Natural history parameters | ||
| Normal epithelium to LR adenomas–age 30 | 0.021 | Model calibration [11] |
| Normal epithelium to LR adenomas–age 50 | 0.020 | Model calibration [11] |
| Normal epithelium to LR adenomas–age 70 | 0.045 | Model calibration [11] |
| Normal epithelium to LR adenomas–age 100 | 0.011 | Model calibration [11] |
| LR adenomas to high-risk adenomas–age 30 | 0.009 | Model calibration [11] |
| LR adenomas to high-risk adenomas–age 50 | 0.008 | Model calibration [11] |
| LR adenomas to high-risk adenomas–age 70 | 0.008 | Model calibration [11] |
| LR adenomas to high-risk adenomas–age 100 | 0.004 | Model calibration [11] |
| HR adenomas to Dukes’ A CRC–age 30 | 0.029 | Model calibration [11] |
| HR adenomas to Dukes’ A CRC–age 50 | 0.025 | Model calibration [11] |
| HR adenomas to Dukes’ A CRC–age 70 | 0.054 | Model calibration [11] |
| HR adenomas to Dukes’ A CRC–age 100 | 0.115 | Model calibration [11] |
| Normal epithelium to CRC Dukes’ A | 0.00004 | Model calibration [11] |
| Preclinical CRC: Dukes’ Stage A to B | 0.51 | Model calibration [11] |
| Preclinical CRC: Dukes’ Stage B to C | 0.69 | Model calibration [11] |
| Preclinical CRC: Dukes’ Stage C to D | 0.71 | Model calibration [11] |
| Symptomatic presentation with CRC Dukes’ A | 0.04 | Model calibration [11] |
| Symptomatic presentation with CRC Dukes’ B | 0.18 | Model calibration [11] |
| Symptomatic presentation with CRC Dukes’ C | 0.37 | Model calibration [11] |
| Symptomatic presentation with CRC Dukes’ D | 0.74 | Model calibration [11] |
| Proportion of cancer incidence classified as proximal | 0.38 | Cancer Registrations 2007, England [32] ] |
| Average number of adenomas present in patient with at least one adenoma | 1.90 | Winawer et al. [3, 33] |
| Proportion of advanced adenomas classified as HR adenomas | 0.75 | FS UK screening trial data [26] |