Table 2.
Demographics, in-hospital therapies, and outcomes among hospitalized patients with COVID-19 during Alpha, Delta, and Omicron predominant time periods.
| Variablesa | All | Time Period |
p valued | ||
|---|---|---|---|---|---|
| T1 (Alpha) | T2 (Delta) | T3 (Omicron) | |||
| n | 566 | 138 (24.38%) | 179 (31.63%) | 249 (43.99%) | |
| Demographics | |||||
| Age, years | |||||
| Mean | 6.68 (6.19) | 8.05 (6.34) | 7.16 (6.30) | 5.57 (5.85) | <0.001b |
| Median | 5.00 (1.00, 13.00) | 7.55 (1.05, 14.35) | 5.90 (1.00, 13.80) | 3.00 (0.00, 10.00) | |
| Age, category | |||||
| Infant (age 0) | 129 (22.79%) | 23 (16.67%) | 35 (19.55%) | 71 (28.51%) | 0.011c |
| Toddler (age 1–4) | 142 (25.09%) | 31 (22.46%) | 45 (25.14%) | 66 (26.51%) | |
| Child (age 5–11) | 130 (22.97%) | 30 (21.74%) | 43 (24.02%) | 57 (22.89%) | |
| Teen (age 12–17) | 165 (29.15%) | 54 (39.13%) | 56 (31.28%) | 55 (22.09%) | |
| Sex | |||||
| Female | 254 (44.88%) | 61 (44.20%) | 78 (43.58%) | 115 (46.18%) | 0.852c |
| Male | 312 (55.12%) | 77 (55.80%) | 101 (56.42%) | 134 (53.82%) | |
| Race | |||||
| Black or African American | 160 (28.27%) | 49 (35.51%) | 45 (25.14%) | 66 (26.51%) | 0.190c |
| White or Caucasian | 339 (59.89%) | 73 (52.90%) | 109 (60.89%) | 157 (63.05%) | |
| Other | 67 (11.84%) | 16 (11.59%) | 25 (13.97%) | 26 (10.44%) | |
| BMI, kg/m2 (n = 547/133/171/243) | |||||
| Mean | 20.13 (7.74) | 21.07 (7.96) | 21.10 (9.16) | 18.93 (6.25) | 0.018b |
| Median | 17.94 (15.57, 21.73) | 18.28 (15.77, 22.93) | 17.94 (15.96, 22.31) | 17.66 (15.27, 20.31) | |
| Vaccination status | |||||
| Boosted | 8 (1.41%) | 0 (0.00%) | 0 (0.00%) | 8 (3.21%) | 0.005c |
| Fully vaccinated | 35 (6.18%) | 6 (4.35%) | 8 (4.47%) | 21 (8.43%) | |
| Partially vaccinated | 15 (2.65%) | 2 (1.45%) | 3 (1.68%) | 10 (4.02%) | |
| Unvaccinated | 508 (89.75%) | 130 (94.20%) | 168 (93.85%) | 210 (84.34%) | |
| In-hospital therapies | |||||
| O2 therapy | 169 (29.86%) | 40 (28.99%) | 68 (37.99%) | 61 (24.50%) | 0.010c |
| Nasal cannula/non-rebreather | 125 (22.08%) | 30 (21.74%) | 54 (30.17%) | 41 (16.47%) | 0.003c |
| High flow O2 | 39 (6.89%) | 9 (6.52%) | 19 (10.61%) | 11 (4.42%) | 0.043c |
| Primary outcomes | |||||
| Composite severe disease | 146 (25.80%) | 50 (36.23%) | 49 (27.37%) | 47 (18.88%) | <0.001c |
| ICU-level care | 119 (21.02%) | 40 (28.99%) | 41 (22.91%) | 38 (15.26%) | 0.005c |
| Mechanical ventilation | 12 (2.12%) | 1 (0.72%) | 3 (1.68%) | 8 (3.21%) | 0.249c |
| MIS-C | 58 (10.25%) | 24 (17.40%) | 18 (10.06%) | 16 (6.43%) | 0.003c |
| Myocarditis | 6 (1.06%) | 5 (3.62%%) | 0 (0.00%) | 1 (0.40%) | 0.005c |
| Death | 3 (0.53%) | 2 (1.45%) | 0 (0.00%) | 1 (0.40%) | – |
| Secondary outcomes | |||||
| Viral co-infection | 68 (12.01%) | 7 (5.07%) | 30 (16.76%) | 31 (12.45%) | 0.006c |
| Length of stay, hours | |||||
| Mean | 69.43 (165.55) | 61.37 (57.46) | 62.46 (64.89) | 78.90 (239.65) | 0.323b |
| Median | 42.00 (24.00, 71.00) | 41.11 (24.04, 72.60) | 46.00 (25.00, 72.00) | 38.00 (22.25, 68.00) | |
Abbreviations: BMI = body mass index; ICU = intensive care unit; MIS-C = multisystem inflammatory syndrome in children; T1 = time period 1 (1/1/21–6/30/21); T2 = time period 2 (7/1/21–12/31/21); T3 = time period 3 (1/1/22–6/16/22).
For continuous variables, medians (interquartile ranges, IQRs) and means (standard deviation, SD) were presented. For categorical variables, frequencies (percentage) were presented.
Kruskal–Wallis test.
Chi-squared or Fisher's exact test.
See Supplementary Table S2A for p-values from multiple comparisons test; post hoc Holm-Bonferroni procedure and the Tukey–Kramer method was used for categorical and numerical variables, respectively.