Table 2.
Model parameters
| Scenario | Parameter type | Parameter | Lower bound | Valuea | Upper bound | Source |
|---|---|---|---|---|---|---|
| All | Model population (triage) | Proportion of hospitalised population with severe COVID-19 | 0.76 | 0.86 | 0.96 | [29] |
| Proportion of hospitalised population with critical COVID-19 | 0.24 | 0.14 | 0.04 | |||
| No critical care | Transition probabilities b | Probability of a patient in the severe state progressing to the critical state | 0.10 | 0.40 | 0.70 | Nominal group exercise |
| Probability of a patient in the severe state progressing to the recover state | 0.10 | 0.20 | 0.25 | |||
| Probability of a patient in the critical state returning to the severe state | 0.00 | 0.05 | 0.15 | |||
| Probability of a patient in the critical state progressing to the death state | 0.50 | 0.70 | 0.80 | |||
| Probability of a patient in the critical state progressing to the recover state | 0.00 | 0.00 | 0.00 | |||
| Intervention effectiveness | Effectiveness of EECC in comparison with ‘no critical care’ in reducing the probability of progressing from the severe state to the critical state | 0.00 | 0.38 | 1.00 | ||
| Effectiveness of EECC in comparison with ‘no critical care’ in increasing the probability of progressing from the critical state to the severe state | 0.00 | 0.50 | 1.00 | |||
| Effectiveness of ACC in comparison with ‘no critical care’ in reducing the probability of progressing from the critical state to death | 0.00 | 0.34 | 1.00 | [10] | ||
| Costs (US$, 2020 prices) | Unit cost of treating a severe patient in a ‘no critical care’ scenario (baseline) | 2.45 | 25.57 | 37.68 | [42] | |
| Unit cost of treating a critical patient in a ‘no critical care’ scenario (baseline) | 2.45 | 25.57 | 37.68 | |||
| Unit cost of treating a severe patient with EECC in a ‘no critical care’ scenario | 8.74 | 10.83 | 22.12 | [44] | ||
| Unit cost of treating a critical patient with EECC in a ‘no critical care’ scenario | 27.92 | 32.84 | 73.92 | |||
| Unit cost of treating a severe patient with ACC in a ‘no critical care’ scenario | 10.82 | 13.11 | 25.65 | |||
| Unit cost of treating a critical patient with ACC in a ‘no critical care’ scenario | 224.65 | 297.30 | 372.12 | |||
| District hospital Level of critical care | Transition probabilitiesb | Probability of a patient in the severe state progressing to the critical state | 0.25 | 0.30 | 0.38 | Nominal group exercise |
| Probability of a patient in the severe state progressing to the recover state | 0.12 | 0.25 | 0.30 | |||
| Probability of a patient in the critical state returning to the severe state | 0.05 | 0.07 | 0.10 | |||
| Probability of a patient in the critical state progressing to the death state | 0.50 | 0.53 | 0.70 | |||
| Probability of a patient in the critical state progressing to the recover state | 0.00 | 0.00 | 0.00 | |||
| Intervention effectiveness | Effectiveness of EECC in comparison with district hospital-level critical care in reducing the probability of progressing from the severe state to the critical state | 0.00 | 0.38 | 1.00 | ||
| Effectiveness of EECC in comparison with district hospital-level critical care in increasing the probability of progressing from the critical state to the severe state | 0.00 | 0.50 | 1.00 | |||
| Effectiveness of ACC in comparison with district hospital-level critical care in reducing the probability of progressing from the critical state to death | 0.00 | 0.34 | 1.00 | [10] | ||
| Costs (US$, 2020 prices) | Unit cost of treating a severe patient in a ‘district hospital-level critical care’ scenario (baseline) | 3.68 | 26.78 | 56.65 | [42] | |
| Unit cost of treating a critical patient in a ‘district hospital-level critical care’ scenario (baseline) | 3.68 | 26.78 | 56.65 | |||
| Unit cost of treating a severe patient with EECC in a ‘district hospital-level critical care’ scenario | 0.26 | 1.87 | 3.95 | [44] | ||
| Unit cost of treating a critical patient with EECC in a ‘district hospital-level critical care’ scenario | 3.28 | 23.88 | 50.51 | |||
| Unit cost of treating a severe patient with ACC in a ‘district hospital-level critical care’ scenario | 0.57 | 4.15 | 8.77 | |||
| Unit cost of treating a critical patient with ACC in a ‘district hospital-level critical care’ scenario | 39.61 | 288.34 | 610.01 | |||
| Health-related quality of life | Disability weight for a severe care episode | 0.09 | 0.13 | 0.19 | [29] | |
| Disability weight for a critical care episode | 0.58 | 0.66 | 0.73 | [29] | ||
| Life expectancy | – | 70.00 | – | Assumption | ||
| Proportion of COVID-19 deaths in patients aged between 18 and 45 years | 0.13 | 0.23 | 0.33 | [35] | ||
| Proportion of COVID-19 deaths in patients aged between 46 and 56 years | 0.14 | 0.24 | 0.34 | |||
| Proportion of COVID-19 deaths in patients aged between 57 and 67 years | 0.22 | 0.32 | 0.42 | |||
| Proportion of COVID-19 deaths in patients aged between 68 and 100 years | 0.11 | 0.21 | 0.31 | |||
All parameters within our analysis were assigned triangular distributions due to a lack of variability around point estimates and an absence of sample data. ACC constitutes EECC in combination with more advanced organ support. EECC is delivered to both severe and critical COVID-19 patients, whereas ACC is only delivered to critical COVID-19 patients. Unit costs are estimated as the incremental cost of providing EECC or ACC relative to the comparator scenario. Severe patients will, by definition, progress to the critical state before dying. Effectiveness values reflect the nominal group exercise where clinicians’ estimated that the probability of patients transitioning from severe to critical is reduced by a factor of 38% and the probability of progressing from the critical state to the severe state is increased by a factor of 50% when EECC is administered, in comparison with the no critical care scenario and the district hospital care scenario
COVID-19 coronavirus disease 2019, EECC Essential Emergency and Critical Care, ACC advanced critical care
aThe value is a measure of central tendency
bSevere patients will, by definition, progress to the critical state before dying