Markov model: assumptions and model variables
Assumptions . | . | |
---|---|---|
• Long-lasting risk reduction of colonoscopy (16, 17); 100% risk reduction in the year of examination and then continuous decrease in subsequent years | ||
• Compliance with screening is the same among individuals who develop CRC and among the general population | ||
• Compliance with screening does not change over time | ||
• Scheme B: utilization of both screening colonoscopies is independent | ||
• Underlying data of CRC incidence describe an unscreened population | ||
• Mortality rates (from all causes of deaths) are the same among individuals who undergo screening and among the general population | ||
Model variables | ||
• Performance characteristics of stool test | ||
Sensitivity, specificity | Variation, 50-100% | |
• Demographic data | ||
Age- and sex-specific population survival rate | Provided by German Federal Statistical Office | |
Age- and sex-specific CRC Incidence | See ref. (15) | |
• Compliance | ||
Compliance with stool testing | ||
(a) Proportion of never-screened subjects | 20% | |
(b) Compliance among remaining subjects | Base case value: 40% (variation, 20-60%) | |
Compliance with follow-up colonoscopy | Base case value: 90% (variation, 80-100%) | |
Compliance with screening colonoscopy | Base case value: 20% (variation, 10-30%) | |
• Annual decrease of risk reduction after colonoscopy | Base case value: 2% (variation, 1-3%) | |
• Target age range for screening | Base case: 55-74 years (variation, 60-74 years) |
Assumptions . | . | |
---|---|---|
• Long-lasting risk reduction of colonoscopy (16, 17); 100% risk reduction in the year of examination and then continuous decrease in subsequent years | ||
• Compliance with screening is the same among individuals who develop CRC and among the general population | ||
• Compliance with screening does not change over time | ||
• Scheme B: utilization of both screening colonoscopies is independent | ||
• Underlying data of CRC incidence describe an unscreened population | ||
• Mortality rates (from all causes of deaths) are the same among individuals who undergo screening and among the general population | ||
Model variables | ||
• Performance characteristics of stool test | ||
Sensitivity, specificity | Variation, 50-100% | |
• Demographic data | ||
Age- and sex-specific population survival rate | Provided by German Federal Statistical Office | |
Age- and sex-specific CRC Incidence | See ref. (15) | |
• Compliance | ||
Compliance with stool testing | ||
(a) Proportion of never-screened subjects | 20% | |
(b) Compliance among remaining subjects | Base case value: 40% (variation, 20-60%) | |
Compliance with follow-up colonoscopy | Base case value: 90% (variation, 80-100%) | |
Compliance with screening colonoscopy | Base case value: 20% (variation, 10-30%) | |
• Annual decrease of risk reduction after colonoscopy | Base case value: 2% (variation, 1-3%) | |
• Target age range for screening | Base case: 55-74 years (variation, 60-74 years) |