Table 1.

Parameter values for the agent-based model

	Symbol	Description	Distribution/valuea	Source
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	Ps	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	RA	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	RS	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	γA	Mean duration of an asymptomatic infection	14 days Sensitivity analysis: Unif(9, 19)	Assumed
Recovery time for symptomatic (moderate, severe) infection	γS	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

^aValues given are fixed in the simulations. Values in brackets were used in sensitivity analyses