Table 1:

Notation for observed data and latent disease topics.

$D$	Number of possible diagnoses, indexed by $d$
$M$	Number of individual patients, indexed by $i$
$N_i$	Total number of diagnoses per patient
$T$	Number of possible time points, indexed by $t$
$w_{idt}$	Observed diagnosis indicator for disease $d$ patient $i$
$K$	Number of postulated topics (comorbidity profiles) indexed by $k$
$z_{idt}$	Latent (i.e. unobserved) index of the topic for diagnosis $d$ in patient $i$ at time $t$