. 2020 Jul 9;17(14):4964. doi: 10.3390/ijerph17144964

Table 1.

Initial parameters of the SEIRD model.

Initial Model Parameters	Definition	Assumption or Constraints
Starting date ^a	The first of the modeling	20 February 2020
N ^b	Total population	5,000,000
S	Susceptible individuals	4,999,999
E	Exposed individuals	0
I_com	Non-hospitalized patients	1
I_hos	Patients hospitalized in non-intensive care wards	0
I_icu	Patients hospitalized in ICU	0
R	Recovered	0
D	Deaths	0
β_com	Transmission rates in the three infectious categories	0.1 ≤ β_com ≤ 2
β_hos		0.1 ≤ β_hos ≤ 2
β_icu		0.1 ≤ β_icu ≤ 2
σ ^c	Infection rate	0.19
υ_com ^d	Probabilities of progressing to I_com, I_hos or I_icu	0.1 ≤ υ_com < 1
υ_hos ^d		0.1 ≤ υ_hos < 0.25
υ_icu ^d		0.1 ≤ υ_icu < υ_hos
γ ^e	Removing rate	0.08
μ_com	Probabilities of dying among I_com, I_hos or I_icu	0 ≤ μ_com < μ_hos
μ_hos		μ_com < μ_hos < μ_icu
μ_icu		μ_hos < μ_icu ≤ 1

^a Assumed to be 5 days (i.e., the incubation period according to Li et al. [11]) before the first case was announced in Sicily on 25 February. ^b Approximated to the current Sicilian population. ^c Assumed to be 1/5.2 days according to Li et al. [11]. ^d Their sum (υ_com + υ_hos + υ_icu) was assumed to be equal to 1. ^e γ Assumed to be 1/12 days based on values reported by Wang et al., Chen et al. and Grasselli et al. [6,12,13].