Table 2.
Demographic and Clinical Factors by Hospitalization and Deceased Status for COVID-19–Positive Residents in Residential Aged Care Facilities During the Omicron-Dominant and Delta-Dominant Epidemic Periods (Row Percentages)
| Delta Period (8/4/2021 to 11/30/2021) | Omicron Period (1/1/2022 to 1/16/2022) | P Value∗ | |
|---|---|---|---|
| Total resident cases, n | 994 | 1882 | |
| Hospitalizations | |||
| Total hospitalizations, n | 245 | 154 | |
| Crude hospitalization risk, % (95% CI) | 24.6 (22.0, 27.3) | 8.2 (7.0, 9.4) | <.001 |
| Median crude hospitalization risk per outbreak (IQR) | 25.0 (9.1, 66.7) | 0.0 (0.0, 9.1) | <.001 |
| Sex, % (n) | |||
| Women admitted to hospital | 23.3 (139) | 6.9 (80) | <.001 |
| Men admitted to hospital | 26.7 (105) | 10.4 (72) | <.001 |
| Age, y, median (IQR) | |||
| Admitted to hospital | 86 (80, 89) | 86 (81, 91) | .26 |
| No hospital admission | 87 (80, 91) | 86 (80, 92) | .53 |
| Vaccination status, % (n) | |||
| Not up to date—hospitalized | 30.8 (28) | 8.6 (104) | <.001 |
| Up to date—hospitalized | 25.1 (165) | 6.7 (38) | <.001 |
| Unknown—hospitalized | 21.2 (52) | 10.8 (12) | .02 |
| Months since last vaccination, median (IQR) | |||
| Admitted to hospital | 4.6 (2.8, 5.8) | 3.9 (2.0, 6.6) | .54 |
| No hospital admission | 4.5 (3.4, 5.5) | 2.5 (1.2, 6.6) | <.001 |
| Deaths | |||
| Total deaths, n | 186 | 214 | |
| Died from COVID-19, % (n) | 13.7 (136) | 6.8 (128) | <.001 |
| Died with COVID-19, % (n)† | 5.0 (50) | 4.6 (86) | .58 |
| Crude case fatality risk, % (95% CI) | 18.7 (16.3, 21.1) | 11.4 (9.9, 12.8) | <.001 |
| Median crude case fatality risk per outbreak, (IQR) | 12.3 (0.0, 27.8) | 0.0 (0.0, 14.3) | <.001 |
| Sex, % (n) | |||
| Women deceased | 16.3 (97) | 9.0 (104) | <.001 |
| Men deceased | 22.6 (89) | 15.9 (110) | .01 |
| Age, y, median (IQR) | |||
| Died | 88 (84, 93) | 88 (83, 93) | .52 |
| Alive | 86 (80, 90) | 86 (80, 91) | .02 |
| Vaccination status, % (n) | |||
| Not up to date—deceased | 15.4 (14) | 13.9 (167) | .69 |
| Up to date—deceased | 18.7 (123) | 6.7 (38) | <.001 |
| Unknown—deceased | 20.0 (49) | 8.1 (9) | .01 |
| Months since last vaccination, median (IQR) | |||
| Died | 4.6 (4.0, 5.7) | 5.5 (1.9, 8.3) | .02 |
| Alive | 4.5 (2.9, 5.6) | 2.2 (1.2, 6.4) | <.001 |
IQR: interquartile range.
∗
P value from chi-squared test for categorical variables or Wilcoxon rank-sum test for continuous variables.
†
Where the person died during the period of interest from another primary cause but where COVID-19 may have contributed.