E L E C T R O N I C S U P P L E M E N T A R Y M A T E R I A L S
Heal h economic e alua ion o colo ec al cance sc eening
policy in Flande s
1. Elec onic Supplemen a y Ma e ial
1.1. Epidemiological es ima es
We used he da a om he yea ly epidemiological epo s om bo h he Belgian Cance Regis y (SKR)
and he Cen e o Cance De ec ion (C KO) o cons uc an adjus ed ull p e alence o CRC in he
popula ion o Flande s. This is analogous o calcula ing he expec ed dis ibu ion o cance s “i e e ybody
was sc eened wi h a pe ec es ”. This akes in o accoun ha he numbe o clinically p esen ing cance s
is no inc easing wi h his hypo he ical es . The g aph below shows he age dis ibu ion o epo ed cases,
and he smoo hed adjus men .
Table 1: Dis ibu ion o epo ed cance s ages be ween pa icipa ion g oups
Dis ibu ion o epo ed CRC
by s age and pa icipa ion ype
Pa icipan s
In e al
cance s
non-
Pa icipan s
CRC S . IV
4.60%
16.90%
23.80%
CRC S . III
11.40%
15.20%
21.40%
CRC S . II
9.70%
14.40%
19.90%
CRC S . I and 0
74.30%
53.50%
34.90%
Figu e 1: Resul ing p e alence cu es be o e and a e adjus men s.
Figu e 2: Diag am o ansi ion p obabili y es ima ion me hod.
To es ima e he ini ial ansi ion p obabili ies (wi hin he unde ec ed g oup) o p og ess h ough he s a es,
we applied a me hodology as desc ibed in he diag am abo e, and in sec ion 2.1 in he a icle. Using he
es ima ed p e alences pe yea and s a e (χi,j in he diag am) we can sol e backwa ds om S age IV o
he equi ed p og ession a es om he p e ious s a e (θi,j o p og essions, γi,j o he emainde ).
Building on he assump ion ha he adjus ed p e alence as abo e is co ec , he diag am can be illed in
h ough a backwa ds induc ion p ocess s a ing wi h CRC S . IV. Because he e a e only known ou lows
om his s a e (dea hs, de ec ions, ea men s) we can sol e he no- ansi ion a e (1-ou lows), and he
in low om CRC S . III o make up he di e ence. A his poin he se o ou lows o CRC S . III a e
ull, and he s eps can be aced back. We do his o mul iple yea s o ake an a e age ansi ion a e.
This p ocess is somewha naï e, in ha i expec s ansi ion a es o emain s agnan o e ime. This could
be al e ed wi h d i pa ame e s, should enough in o ma ion be a ailable o es ima e hese. A bene i o
his me hod is ha he esul ing ansi ion a es gi e he model a sense o g a i y owa ds he cu en s a e
o CRC in he popula ion. I.e. These a es end o p oduce a long- un s a e no oo dissimila om he
cu en s a e, i no changes in sc eening occu . Ano he bene i s ems om he ease in which his p ocess
could be au oma ed wi h yea ly epo ed da a, meaning ha he go e nmen could easily use his ool o
make a new e alua ion wi h u u e epidemiological da a.
The esul ing ansi ion a es a e shown in he able below.
Table 2: esul ing ansi ion p obabili ies wi hin he unde ec ed g oup.
Males
Females
F om
Heal hy
Polyp. Ad.
CRC1
CRC2
CRC3
Heal hy
Polyp. Ad.
CRC1
CRC2
CRC3
To
Polyp. Ad.
CRC1
CRC2
CRC3
CRC4
Polyp. Ad.
CRC1
CRC2
CRC3
CRC4
Age
45
0.002
0.070
0.273
0.857
0.710
0.002
0.069
0.268
0.840
0.696
46
0.002
0.067
0.275
0.866
0.718
0.002
0.065
0.268
0.843
0.699
47
0.002
0.065
0.277
0.874
0.726
0.002
0.062
0.268
0.846
0.703
48
0.002
0.063
0.279
0.883
0.735
0.002
0.060
0.268
0.848
0.706
49
0.003
0.062
0.281
0.891
0.744
0.003
0.059
0.268
0.850
0.710
50
0.003
0.061
0.283
0.899
0.753
0.003
0.058
0.268
0.852
0.713
51
0.003
0.061
0.285
0.907
0.761
0.003
0.057
0.268
0.853
0.716
52
0.003
0.061
0.287
0.914
0.769
0.003
0.057
0.268
0.854
0.719
53
0.003
0.061
0.288
0.920
0.777
0.003
0.057
0.268
0.855
0.722
54
0.004
0.062
0.290
0.926
0.785
0.004
0.057
0.267
0.854
0.724
55
0.004
0.063
0.291
0.932
0.792
0.004
0.057
0.267
0.854
0.726
56
0.004
0.064
0.293
0.936
0.799
0.004
0.058
0.266
0.852
0.727
57
0.005
0.065
0.294
0.941
0.806
0.004
0.059
0.266
0.850
0.729
58
0.005
0.066
0.295
0.944
0.812
0.005
0.060
0.265
0.848
0.730
59
0.005
0.068
0.296
0.948
0.819
0.005
0.061
0.264
0.845
0.730
60
0.005
0.070
0.297
0.951
0.825
0.005
0.062
0.263
0.842
0.731
61
0.006
0.072
0.298
0.953
0.830
0.005
0.063
0.262
0.839
0.731
62
0.006
0.074
0.298
0.956
0.836
0.006
0.064
0.261
0.836
0.731
63
0.007
0.076
0.299
0.958
0.841
0.006
0.066
0.260
0.832
0.731
64
0.007
0.078
0.300
0.962
0.854
0.006
0.067
0.259
0.830
0.737
65
0.007
0.080
0.301
0.965
0.866
0.007
0.069
0.258
0.827
0.743
66
0.008
0.083
0.301
0.968
0.877
0.007
0.071
0.257
0.824
0.747
67
0.008
0.085
0.302
0.971
0.887
0.008
0.072
0.255
0.821
0.750
68
0.009
0.088
0.303
0.973
0.896
0.008
0.074
0.254
0.818
0.753
69
0.009
0.091
0.303
0.975
0.904
0.008
0.076
0.253
0.814
0.755
70
0.010
0.094
0.304
0.977
0.912
0.009
0.078
0.252
0.810
0.757
71
0.010
0.097
0.304
0.978
0.919
0.009
0.080
0.251
0.806
0.758
72
0.011
0.100
0.305
0.980
0.926
0.010
0.082
0.250
0.802
0.758
73
0.011
0.103
0.305
0.981
0.933
0.010
0.083
0.248
0.798
0.759
74
0.012
0.106
0.306
0.982
0.939
0.011
0.085
0.247
0.793
0.759
75
0.012
0.102
0.286
0.919
0.879
0.011
0.082
0.230
0.738
0.705
1.2. Sc eening a es
The sc eening pa icipa ion is an impo an dynamic in his model, so we ook ca e o c ea e a
me hodology ha accoun ed o su icien eal-wo ld complexi y. This s a ed wi h designing wo
schedule ma ices, as shown below.
Figu e 3: Sc een Wa e Ma ices o he Cu en ( op) and Expanded (bo om) sc eening scena ios.
Fig. 2. These ma ices show he logic behind he sc eening pa icipa ion o he cu en and expanded sc eening
scena ios. Blue indica es ha his age does no pa icipa e in s a e sc eening. G een indica es a yea -age
combina ion whe e mos people a e in i ed o pa icipa e. Red means a yea -age combina ion whe e people a e
less likely o be in i ed. A ipple can be seen in his s uc u e, as a esul o p e ious s agge ed expansions in he
a ge sc eening demog aphic.
Age 75
Yea
2023 SP SP SP SP SP
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2024 SP SP SP SP SP
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2025 SP SP SP SP SP
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2026 SP SP SP SP SP
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2027 SP SP SP SP SP
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2028 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
SP
2029 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
SP
2030 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
SP
2031 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
SP
2032 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
SP
2033 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
SP
2034 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
SP
2035 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
SP
2036 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
SP
2037 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
High
Low
SP
2038 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
Low
Low
SP
2039 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
High
High
SP
2040 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
High
Low
SP
2041 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
Low
Low
Low
SP
2042 SP SP SP SP SP
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
High
High
SP
Legend: Spon aneous sc eening only (blue), scheduled in i e yea (g een), unscheduled in i e yea ( ed)
70 -74
65 - 69
60 -64
55 - 59
50 - 54
45 - 49
Age 75
Yea
2023 SP SP SP SP
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2024 SP SP
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2025
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2026
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2027
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
Low
High
SP
2028
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
Low
High
SP
2029
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
Low
High
SP
2030
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
Low
High
SP
2031
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
Low
High
SP
2032
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
Low
High
SP
2033
High
Low
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
Low
High
SP
2034
High
Low
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
Low
High
SP
2035
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
Low
High
SP
2036
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
High
High
SP
2037
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
High
Low
SP
2038
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
Low
Low
SP
2039
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
High
High
SP
2040
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
High
Low
SP
2041
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
High
High
Low
Low
Low
High
High
Low
High
High
Low
Low
Low
SP
2042
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
Low
Low
High
High
High
Low
Low
High
Low
Low
High
High
SP
Legend: Spon aneous sc eening only (blue), scheduled in i e yea (g een), unscheduled in i e yea ( ed)
45 - 49
50 - 54
55 - 59
60 -64
65 - 69
70 -74
The nex s ep was o es ima e he in i a ion a es ha co espond o he ed/g een yea -age combina ions
as seen in he ma ices abo e. To be able o eely change model any changes in he sc eening schedule,
we es ima ed an in i a ion a e o scheduled yea s (g een) and unscheduled yea s ( ed). Because a no -
insigni ican pe cen age is in i ed ou side scheduled yea s, we inco po a ed his is he model. We i ed
3 d o de polynomials o he da a, s a i ied by age and schedule. We applied a ceiling o he maximum
a es o ne e all abo e o below obse ed a es. This same p ocess was pe o med on he p obabili y o
pa icipa e in sc eening, condi ional on being in i ed.
Figu e 4: In i a ion and Pa icipa ion Ra es
This wo-s ep di e en ia ion be ween in i a ion and pa icipa ion allowed us o sepa a e ou wo di e en
dynamics. Fi s , ha in i a ions dec ease wi h age (as mo e people op ou o a e excluded o medical
easons), and also become less s a i ied acco ding o he schedule. Second, ha in insically people
become mo e likely o pa icipa e as hey age.
Using hese h ee p inciples oge he (wa e ma ices, in i a ion a e, and pa icipa ion a e) on pas yea s
allows o compa e he esul ing numbe o es s e sus he epo ed numbe o es s (a e aged o e 4
yea s), as shown in he igu e below.
Figu e 5: Numbe o es s, p edic ed and epo ed.
O e all, he “ e odic ion” ends o ollow he ac ual pa e n well. I ends o unde es ima e he peaks and
o e es ima e he oughs, bu o only a small amoun . The ne esul is a sligh unde es ima ion o he
numbe o es s o less han 5% on he sho un. This esul s p ima ily om he o e es ima ion o
exclusions in he younge age g oups, which is likely o become mo e accu a e in he long un.
1.3. Inpu Cos s and Disu ili ies in he Model
The ollowing able shows he disu ili ies ha ha e been applied o each heal h s a e. These disu ili ies
a e applied ela i e o he heal hy u ili y sco e by age-yea . The heal hca e cos s agg ega ed by speci ic
heal h s a e a e also shown, as is a compa ison o he cos applied in he p io model [1]. The sou ces o
hese speci ied below he able. All cos s a e indexed o 2022 using he Heal hca e cos s index.
Table 3: Cos s and disu ili ies
Disu ili ies and cos s pe heal h s a e, agg ega ed alues
Heal h S a e
Disu ili y
Re .
Heal hca e cos
P io Values*
Re .
Ad. Polyp
0.065
[1]
n/a
n/a
Uniden i ied CRC S . I
0.085
[1]
n/a
n/a
Uniden i ied CRC S . II
0.085
[1]
n/a
n/a
Uniden i ied CRC S . III
0.140
[1]
n/a
n/a
Uniden i ied CRC S . IV
0.655
[1]
n/a
n/a
T ea men CRC S . I
0.170
[1]
€ 15,263
€ 12,808
[1, 2]
T ea men CRC S . II
0.170
[1]
€ 27,071
€ 22,716
[1, 2]
T ea men CRC S . III
0.280
[1]
€ 33,251
€ 31,351
[1, 2]
T ea men CRC S . IV
0.655
[1]
€ 39,634
€ 37,369
[1, 2]
Follow-up yea s 1-4 CRC S . I
0.128
[1]
€ 9,730
€ 7,795
[1, 2]
Follow-up yea s 1-4 CRC S . II
0.128
[1]
€ 7,349
€ 5,888
[1, 2]
Follow-up yea s 1-4 CRC S . III
0.210
[1]
€ 4,733
€ 3,992
[1, 2]
Follow-up yea s 1-4 CRC S . IV
0.655
[1]
€ 13,837
€ 11,669
[1, 2]
Follow-up yea s >4 CRC S . I
0.064
[1]
€ 241
€ 202
[1, 2, 3]
Follow-up yea s >4 CRC S . II
0.064
[1]
€ 241
€ 202
[1, 2, 3]
Follow-up yea s >4 CRC S . III
0.105
[1]
€ 4,733
€ 3,992
[1, 2]
Follow-up yea s >4 CRC S . IV
0.328
[1]
€ 13,837
€ 11,669
[1, 2]
False posi i e esul
0.021
[1]
n/a
n/a
Colonoscopy
0.003
[1]
€ 241
€ 202
[3]
Polypec omy
0.014
[1]
€ 540
€ 393
[3]
[1] Pil, L., Fobele s, M., Pu man, K., T ybou, J., & Annemans, L. (2016). Cos -e ec i eness and budge impac analysis o a
popula ion-based sc eening p og am o colo ec al cance . Eu opean jou nal o in e nal medicine, 32, 72-78. DOI:
10.1016/j.ejim.2016.03.031
[2] Pacole , J., De Coninck, A., Hedebouw, G., Cabus, S., & Sp uy e, N. (2011). De medische en nie -medische kos en an
kanke pa iën en. ISSN: 978-90-5550-481-7
[3] RIZIV Rijksins i uu oo ziek e- en in alidi ei s e zeke ing. NomenSo . A ailable a :
h ps://www. izi . go .be/webp d/appl/pnomen/Sea ch.aspx?lg=N.
1.4. Resul s: To al cos s and bene i s
The ollowing ables show he esul ing o al cos s and bene i s be ween he h ee scena ios. Cos s a e
sepa a ed be ween “sc eening cos s” (p og amme cos s), heal hca e cos s o all esul ing ea men s, and
he socie al cos s ( om los labou p oduc ion). These a e shown in he de e minis ic case, he
p obabilis ic a e age, and he s anda d e o . Finally, hese a e also shown as a p opo ion o he pe son
yea s in he model. The inal able also shows he gene al b eakdown o heal hca e cos s pe scena io,
in o cos s made o sc eening (FIT and ixed cos s), colonoscopies (and polypec omies), cance
ea men s, and ollow-up cos s. The las wo ca ego ies a e he main d i e s o o al cos s.
Table 4: To al cos s and bene i s pe scena io
Cos s pe scena io
To al (20 yea , in Millions)
A e age pe yea (in Thousands)
De .
P ob.
A g.
S . E .
De .
P ob.
A g.
S . E .
A g.
p.p.y.
Sc eening cos s
No Sc eening
0 M
0 M
(0.0)
0 K
0 K
(0.0)
0.0
Cu en Sc eening
75 M
79 M
(7.6)
3,404 K
3,781 K
(364.2)
0.6
Expanded Sc eening
79 M
84 M
(8.4)
3,594 K
3,991 K
(401.1)
0.6
Heal hca e cos s
No Sc eening
4,817 M
5,102 M
(243.9)
219,049 K
242,973 K
(11615.7)
35.7
Cu en Sc eening
4,723 M
4,999 M
(2595)
214,703 K
238,034 K
(12359.4)
34.9
Expanded Sc eening
4,719 M
4,994 M
(260.4)
214,507 K
237,823 K
(12401.3)
34.8
Labou cos s
No Sc eening
13,509 M
19,418 M
(0.9)
614,046 K
924,668 K
(42.9)
135.7
Cu en Sc eening
13,456 M
19,337 M
(0.9)
611,618 K
920,813 K
(42.9)
134.9
Expanded Sc eening
13,453 M
19,335 M
(0.9)
611,518 K
920,705 K
(42.9)
134.8
Table 5: B eakdown o Heal hca e cos pe scena io and ca ego y
Cos b eakdown pe scena io
No Sc eening
Cu en Sc eening
Expanded Sc eening
Sc eening Cos s
0.6%
2.0%
2.1%
Colonoscopies and
polypec omies
2.6%
5.2%
5.3%
T ea men cos s
49.5%
44.2%
43.9%
Pos -T ea men cos s
47.3%
48.7%
48.7%
Bene i s pe
scena io
QALYs ( o al)
Pe pe son-yea
Li e yea s ( o al)
De .
P ob.
A g.
S . E .
De .
P ob.
A g.
De .
P ob.
A g.
S . E .
No Sc eening
79,073K
79,007K
(5175.4)
0.5474
0.5469
113,183 K
113,196 K
(5309)
Cu en Sc eening
79,266K
79,197K
(5184.3)
0.5487
0.5482
113,384 K
113,395 K
(5319)
Expanded Sc eening
79,274K
79,206K
(5184.7)
0.5488
0.5483
113,396 K
113,407 K
(5320)
