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 |