Table 1 Parameter values for the agent-based model

Incubation period

s(τ)

Time between infection and symptom onset

Gamma distribution

Shape = 5.807

Scale = 0.948

Mean = 5.510

SD = 2.284

Lauer et al. [15]

Generation time

ω(τ)

Time between becoming infected and subsequent onward transmission events

Weibull distribution

Shape = 2.826

Scale = 6.839

Mean = 6

Grassly et al. [14]

Proportion of asymptomatic infections among infected patients

\( {P}_A^p \)

20%

Buitraga-Garcia et al. [20]

Proportion of asymptomatic infections among infected HCWs

\( {P}_A^h \)

31%

Buitraga-Garcia et al. [20]

Proportion of severe symptomatic individuals

P_s

Proportion of exposed individuals that will develop severe symptoms

20%

Wu et al. [21]

Reproduction number of asymptomatic infectees for wild-type variant

\( {R}_A^W \)

Mean number of infections caused by an individual asymptomatically infected with the wild-type SARS-CoV-2 variant

0.5

Calibrated to UMCU data

Reproduction number of symptomatic infectees for wild-type variant

\( {R}_S^W \)

Mean number of infections caused by an individual symptomatically infected with the wild-type SARS-CoV-2 variant

1.25

Calibrated to UMCU data

Reproduction number of asymptomatic infectees for new virus variant

R_A

Mean number of infections caused by an individual asymptomatically infected with the SARS-CoV-2 variant

0.8 (1.95)

Based on \( {R}_A^W \) with 56% higher transmissibility, varied in sensitivity analysis

Reproduction number of symptomatic infectees for new virus variant

R_S

Mean number of infections caused by an individual symptomatically infected with the SARS-CoV-2 variant

1.95

Based on \( {R}_A^W \) with 56% higher transmissibility

Maximum sensitivity of diagnostic PCR test

93.1% (79%)

Grassly et al. [14], varied in sensitivity analysis

Proportion of HCWs that work in the same ward as during their previous shift

95% (baseline)

100% (intervention)

Assumed

PPE effectiveness

Reduction in infectiousness upon contact between an infected and susceptible individual (includes PPE efficacy and adherence)

90% (50%, 70%)

Suzuki et al. [22], Qian et al. [23] and Bessesen et al. [24], varied in sensitivity analysis

Isolation period for HCWs

Amount of time HCWs have to isolate after symptom onset or after being detected by screening or contact tracing

7 days

Assumed

Recovery time for asymptomatic infection

γ_A

Mean duration of an asymptomatic infection

14 days

Sensitivity analysis: Unif(9, 19)

Assumed

Recovery time for symptomatic (moderate, severe) infection

γ_S

Mean duration of a symptomatic infection

14 days (moderate)

35 days (severe)

Sensitivity analysis:

Unif(9, 19)

Unif(30, 40)

Liu et al. [16]

LoS of non-COVID patients in ICU

Lognormal

meanlog = 0.37

sdlog = 0.82

Mean = 1.45 days

sd = 2.27

Fitted distributions to UMCU data from 2014-2017

LoS of non-COVID patients in normal ward

Weibull

Shape = 0.92

Scale = 4.18

Mean = 4.35 days

Fitted distributions to UMCU data from 2014-2017

LoS of moderately infected patients

Gamma

Shape = 1.88

Rate = 0.25

Mean = 31.8 days

sd = 30.08

Fitted distributions to UMCU data from 2020

LoS of severely infected patients

Gamma

Shape = 1.59

Rate = 0.05

Mean = 7.52 days

sd = 636

Fitted distributions to UMCU data from 2020