Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Partial differential equation about the prevalence of a chronic disease
  in the presence of duration dependency   The illness-death model of a chronic disease consists of the states 'Normal',
'Disease' and 'Death'. In general, the transition rates between the states
depend on three time scales: calendar time, age and duration of the chronic
disease. Previous works have shown that the age-specific prevalence of the
chronic disease can be described by differential equations if the duration is
negligible. This article derives a partial differential equation (PDE) in the
presence of duration dependency. As an important application, the PDE allows
the calculation of the age-specific incidence from cross-sectional surveys.

26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an