Migration Network Model
Notation	Definition
${\mu }_i,\forall i\in \mathcal{I}$	The service rate at node i.
${\lambda }_i,\forall i\in \mathcal{I}$	The arrival rate of new patients at node i.
${\sigma }_i,\forall i\in \mathcal{I}$	Follow-up rate of patients at node i.
δ	The departure rate of patients in the system.
γ	Disease progression rate.
pc	The probability that the patients diagnosed in the controlled health state remain in the controlled health state after a virtual appointment.
pu	The probability that the patients diagnosed in a uncontrolled health state improve to controlled health state after a virtual appointment.
$p_{j|j^{\prime }},j,j^{\prime }\in \mathcal{J}$	The probability that patient in health state $j^{\prime }$ is diagnosed in health state j during the virtual appointment.
ph	The probability that the new arrived patient in virtual appointment is in the controlled health state.
wc	System state for patients who are in the controlled health state and not scheduled for an appointment
wu	System state for patients who are in the uncontrolled health state and not scheduled for an appointment.
so	System state that represents patients scheduled for office appointment.
sv,c	System state that represents patients scheduled for virtual appointment and in the controlled health state.
sv,u	System state that represents patients scheduled for virtual appointment and in the uncontrolled health state.
${\alpha }_i,i\in {\mathcal{K}}^{\prime }$	The expected number of patients at node i at the steady-state condition.