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those about sexuality. Moreover, before that date, there is no full registry on
new cancer cases and until 1999 only part of the data are available (since 1999
National Cancer Registry [21] has been publishing very detailed data on-line).
Another important change happened around 2006, when Poland introduced pop-
ular screening program. At present (2013), it is recommended to women between
25 and 60 to screen every 3 years, but only little above 20% of them do it [24]
(effective screening frequency is around every 15 years). To capture this in the
model, we differentiate screening values into 3 periods (Figure 3):
- until 2005: there was no regular screening, and tests are done when physicians
ask for that,
- 2006
−
2015: when regular screening procedures are introduced,
- 2016
2039: where we predict that screening effectiveness will be continuously
improving (starting from every 10 years, which means that 1
/
3 of women will
follow 'every 3 years rule').
−
We choose only 25 years timespan for prediction, because of the rapid change
in medical treatments. For example, screening test in our model is allowed to
detect only women ”permanently” colonized, in StageII, but there already exist
PCR-tests (where even genomic sequence can be obtained), which detect pres-
ence of virus in every stage. However, they are too expensive for common use
now. Demographic prediction also cannot look too much ahead, because we did
not take into account factors such as migration. Time step of simulation is 0
.
1
day (it has to be very small to avoid averaging because of stochastic character
of simulation).
Demographics.
Population in this model consists of sexually active Poles, who
are leaving the system after reaching 65 years old. Exception are women from
Fig. 3.
Screening frequencies (every x years)
