Table 2. Key NCEM parameter values and their evolution between April and September 2020.
| Parameter | April 2020 | September 2020 | ||
|---|---|---|---|---|
| Value* (range) | Sources | Value* (range) | Sources | |
| Infection severity and transmission** | ||||
| Proportion of cases that are asymptomatic | 75% | [9–11] | 75% (70%–80%) | [8–11] |
| Relative infectiousness of asymptomatic cases | - | - | 80% (77.5%, 82.5%) | [12–14] Estimated through calibration to admissions and fatalities count data (DATCOV) [15] |
| Mild to moderate cases among the symptomatic | (95.64%, 96.78%) | adjusted based on [17] | (94.55%–97.13%) | Estimated through calibration to admissions and fatalities count data (DATCOV) [15,16] |
| Severe cases among the symptomatic | (2.46%–3.64%) | (2.58%–5.00%) | ||
| Critical cases among the symptomatic | (1.16%–1.45%) | (0.18%–0.55%) | ||
| Proportion of cases that are fatal | (0.30%, 0.412%) | [17,18] | ||
| Timeframes & treatment duration | ||||
| Time from infection to onset of infectiousness | 4 days (2–9) | [18,19–23], with additional input from analysis of NICD data | 2 days (1–3) | [24–34] with input from the National COVID-19 Modelling Consortium |
| Time from onset of infectiousness to onset of symptoms | 2 days (1–4) | 4 days (3–5) | ||
| Duration of infectiousness from onset of symptoms | 5 days | 5 days (4–6) | [35,36] | |
| Time from onset of mild symptoms to testing | 4 days (2–4) | 4 days (3–5) | [25,26,18–21,23] | |
| Time from onset of symptoms to hospitalisation | 5 days (4–8) | 5 days (4–6) | ||
| Time from onset of symptoms to ICU admission | 9 days (8–17) | see below | ||
| Duration of hospital stay | 12 days (7–16) | |||
| Duration from ICU admission to discharge | 18 days (14–18) | |||
| Duration from ICU admission to death | 5 days (4–7) | |||
| Time in non-ICU (never ICU) to death/recovery | 8 days (4–12) | Lengths of stay: values and ranges sourced from NICD COVID-19 Hospital Sentinel Surveillance database (DATCOV) [15,4] | ||
| Time in non-ICU for those destined for ICU | 0 days (0–2) | |||
| Time in ICU for those ventilated and destined to die | 14 days (7–27) | |||
| Time in ICU for those never ventilated and destined to die | 11 days (7–18) | |||
| Time in ICU for those ventilated and recovered | 19 days (15–37) | |||
| Time in ICU for those never ventilated and recovered | 5 days (1–10) | |||
| Time in non-ICU for those who were in ICU and recovered | 0 days (0–6) | |||