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Table 1 Parameter values with description and range of parameters explored as well as the values used in the case study. For all details on calculations see Additional file 1

From: Quantifying where human acquisition of antibiotic resistance occurs: a mathematical modelling study

Symbol Parameter description Range Case study Notes and references
N Total population size 100,000 100,000 Fixed
N h Size of the total population in hospital (0.02% to 3%)N 0.25% Fixed in baseline [37], explored in sensitivity analysis
N c Size of the total population in the community (1 – [0.02% to 3%])N 1–0.25% Depends on Nh
α Rate at which those in the community enter the hospital 2 × 10−4 to 2 × 10−3 per day 8 × 10− 4 per day Linked to number of admissions per day [38]
l Rate at which those hospitalised return to the community 0.05 to 1 per day 0.32 per day Varied to fit Nh
b Background death rate Fixed 1/(81*365) Inverse of life expectancy [39]
ε Proportion that acquire resistance during each antibiotic treatment 0.0008 to 0.13 0.0135 per treatment Estimates taken from a range of studies (see Additional file 1)
ωc Rate of antibiotic exposure in community (1 to 15)/1000 per day 8.6/1000 per day Using total consumption in England in 2014 [23] and point prevalence surveillance data [40]
ωh Rate of antibiotic exposure in hospital (0.5 to 1.00)ωc 0·22 per day
βh Transmission rate in the hospital 0.1 to 10 per day 1.8 per day Case study value calibrated [14, 41]. Assumed to be the same or lower in the community
βc Transmission rate in the community βh/25 to 2βh βh
c Rate of clearance of resistant bacteria in community 1/730 to 1/42 per day 1/127 per day Estimates taken from a range of studies (see Additional file 1)
i c Rate of infection in the community (1.4 to 2.8) × 10− 6 1.75 × 10− 6 [42]
i h Rate of infection in the hospital (5 to 500)ic 100ic Assumed to be higher in hospitals due to patient co-morbidities.
r inf Decreased rate of infection by resistant organisms 0.5 to 1 0.8 Most ARB have reduced fitness, which can be ameliorated. (see Additional file 1)
μr Proportion of infections with resistant bacteria that result in death 0.4 to 0.9 0.6 Case study value based on bacteraemia data [27]
μc Proportion of infections with susceptible bacteria that result in death 0.1 to 0·5 0.2