Table 2: Parameter values related to healthcare usage and deaths.
| Parameter | 1st February 2020–31st March 2020 | 1st April 2020–31st May 2020 | 1st June 2020–31st July 2020 | 1st August 2020–30th September 2020 | 1st October 2020–30th November 2020 | 1st December 2020–31st January 2021 |
|---|---|---|---|---|---|---|
| Percentage of hospitalizations (calibrated), %┴ | 19.0 | 11.6 | 2.0 | 2.7 | 3.4 | 4.1 |
| Percentage of hospitalizations (baseline), %┴┴ | 11.3 | 12.5 | 10.5 | 3.8 | 3.5 | 4.0 |
| Percentage of ICU admissions (among hospitalized cases), %° | 33.9 | 22.9 | 21.8 | 24.3 | 32.5┴ | 30.5┴ |
| Percentage of ICU admissions with mechanical ventilation, %° | 75.7 | 64.7 | 51.1 | 45.1 | 33.6┴ | 42.5┴ |
| Average LOS in ward (non-fatal cases), days° | 22.86 | 23.07 | 14.27 | 12.66 | 12.66* | 12.66* |
| Average LOS in ward (fatal cases), days° | 32.70 | 13.74 | 24.48 | 21.98 | 21.98* | 21.98* |
| Average LOS in ICU w/o ventilation (non-fatal cases), days° | 5.30 | 5.00 | 6.20 | 5.50 | 5.50* | 5.50* |
| Average LOS in ICU w/o ventilation (fatal cases), days° | 4.80 | 3.40 | 5.50 | 5.80 | 5.80* | 5.80* |
| Average LOS in ICU with ventilation (non-fatal cases), days° | 25.10 | 26.40 | 30.20 | 18.60 | 18.60* | 18.60* |
| Average LOS in ICU with ventilation (fatal cases), days° | 14.00 | 16.90 | 17.70 | 22.10 | 22.10* | 22.10* |
| Percentage of deaths among non-critical cases (ward only), %° | 15.2 | 23.4 | 10.6 | 12.7 | 12.7* | 12.7* |
| Percentage of deaths among cases admitted to ICU w/o ventilation, %° | 19.5 | 23.9 | 16.5 | 11.5 | 11.5* | 11.5%* |
| Percentage of deaths among cases admitted to ICU with ventilation, %° | 35.5 | 46.5 | 44.2 | 51.7 | 51.7* | 51.7* |
Abbreviations: ICU, intensive care unit; LOS, length of stay; w/o, without.
┴These values were calibrated from the Ontario baseline values based on the model best fit (MAPE for cumulative reported cases = 0.8%, MAPE for hospitalizations = 8.5%, MAPE for ICU admissions = 12.8%, MAPE for ICU admissions with ventilation = 18.4%, see also Figure).
┴┴The baseline values for the percentage of cases hospitalized were estimated as the percentage of “total confirmed cases” “ever hospitalized” for the reported period from the daily epidemiologic summaries from Public Health Ontario [28]. Detailed calculations are presented in Appendix Table A2.4. Note that the percentage of cases hospitalized cannot be accurately determined from the existing data as there is no linkage between the testing data and the hospitalization data.
°Based on the detailed information on acute care hospitalizations for patients with a diagnosis of COVID-19 in CIHI’s COVID-19 Hospitalization and Emergency Department Statistics, 2019–2020 and 2020–2021 [29]. Detailed COVID-19 episode of care breakdowns for modelling, by recipient province/territory and admission month, DAD, January to November 2020” Table.
*The values for LOS and fatality rates for the 1st October 2020–30th November 2020 and 1st December 2020–31st January 2021 time periods were assumed to be the same as for the 1st August 2020–30th September 2020 period. While the parameters from the DAD data were available up to 30th November 2020, the last period couldn’t be included in the analysis, as a significant proportion of cases hospitalized from 1st October 2020–30th November 2020 are discharged after 30th November 2020 and will not be included in the reported data.