Report in English with a Dutch summary (KCE reports 45A)

146 Screening for Colorectal Cancer: Appendices KCE reports vol.45
only after a positive FOBT. We therefore used a central estimate of
colonoscopy detection rates of 10% for CRC (in a Beta-distribution ranging
from 5 tot 15%) and of 20% for adenomata (in a skewed Beta-distribution
ranging from 10 to 35%)
8.1.1.7 Complication rates from colonoscopy after positive FOBT
8.1.1.8 Costs
Reporting of complication rates differs in the RCTs. In the Minnesota trial there
would be 0,034% complications from colonoscopy (perforations and
hemorrhage). In the Göteborg RCT the complication rate was 0,018%. A recent
large series of colonoscopies in Poland 594 showed overall complication rates of
0,1% (including mainly perforation, bleeding, cardiovascular events and a few
other complications), while perforation rate was 0,01%. In the French series of
colonoscopies performed for all reasons and not merely screening (see table
19), reported perforation rate was 0,07% and hemorrhage 0,28% and an overall
complication rate of 0,47% using a broad definition of complications . However,
as mentioned in chapter 5 complication risk is significantly higher in therapeutic
colonoscopy than in diagnostic endoscopies, due to the higher rate of
polypectomies and biopsies. For the purpose of this budget impact model we
accept a large variability in the complication rate parameter and we estimated
only the cost of perforation. To apply this we used a perforation rate of 0,05%
ranging from 0,01 to 0,1% in a skewed Beta-distribution.
Wherever possible, known Belgian costs have been applied. This is especially so
for GP visits, cost of colonoscopy (with associated bowel preparation, sedation,
anaesthesia and anatomopathology), cost for FOBT test kits and the lab. These
costs were obtained from the Belgian national reimbursement tariffs (RIZIV-
INAMI). For this analysis we also assumed that the FOBT testing would be
entirely covered by the screening program. It should be noted that models
where the cost of the test kits are not covered by the program, or where
price-volume negotiations with the distributor lead to lower prices for the test,
result in lower estimates for budget impact and cost per CRC detected. The
cost of the complication of perforation during colonoscopy was based on costs
used in published economic evaluations (see evidence table of chapter 6) and on
Belgian expert opinion.
For other costs, such as up-front campaign cost (media, flyers, setting up
infrastructure) and mailing costs no hard data were available. These were
estimated, based on grey literature and expert opinion. For uncertain cost
estimates, a distribution was defined by the multiplication of the point estimate
for costs with a factor drawn from a skewed Beta-distribution with mean 1,
minimum 0,5 and maximum 2. This means that an uncertainty range is defined
of 0,5 times the mean cost to 2 times the mean cost.
An overview of the assumptions and parameter values is presented in table 30.