Baseline characteristics of patients presenting with ischemic stroke before (Jan. 1, 2016 to Feb. 27, 2020) and during (Feb. 28, 2020 to Mar. 31, 2021) the first year of the COVID-19 pandemic in Alberta, Canada
| Characteristic | No. (%) of patients in prepandemic period* n = 19 529 | No. (%) of patients in pandemic periods*,† | |||||
|---|---|---|---|---|---|---|---|
| Overall n = 4900 | Wave 1 n = 851 | Lull n = 921 | Wave 2.1 n = 1041 | Wave 2.2 n = 1616 | Wave 3 n = 471 | ||
| Age, yr, median (IQR) | 72 (60–82) | 71 (61–82) | 72 (62–81) | 71 (61–82) | 71 (60–81) | 72 (62–83) | 70 (60–80) |
| Unadjusted difference (95% CI) | Ref. | −0.1 (−0.6 to 0.4) | 0.2 (−0.9 to 1.2) | 0.4 (−0.6 to 1.4) | −0.8 (−1.7 to 0.2) | 0.7 (−0.02 to 1.5) | −0.9 (−2.3 to 0.5) |
| Sex, female | 9100 (46.6) | 2242 (45.8) | 416 (48.9) | 433 (47.0) | 463 (44.5) | 730 (45.2) | 200 (42.5) |
| Unadjusted OR (95% CI) | Ref. | 1.03 (0.97 to 1.10) | 0.91 (0.80 to 1.05) | 0.98 (0.86 to 1.12) | 1.09 (0.96 to 1.23) | 1.06 (0.96 to 1.17) | 1.18 (0.98 to 1.42) |
| Age-adjusted OR (95% CI) | Ref. | 1.04 (0.97 to 1.10) | 0.91 (0.80 to 1.05) | 0.99 (0.87 to 1.13) | 1.08 (0.95 to 1.22) | 1.07 (0.97 to 1.19) | 1.17 (0.97 to 1.41) |
| Admitted to hospital | 15 344 (78.6) | 3934 (80.3) | 704 (82.7) | 735 (79.8) | 818 (78.6) | 1313 (81.3) | 364 (77.3) |
| Minor stroke (not admitted) | 4185 (21.4) | 966 (19.7) | 147 (17.3) | 186 (20.2) | 223 (21.4) | 303 (18.8) | 107 (22.7) |
| Unadjusted OR (95% CI) | Ref. | 0.90 (0.83 to 0.97) | 0.77 (0.64 to 0.92) | 0.93 (0.79 to 1.09) | 1.00 (0.86 to 1.16) | 0.85 (0.74 to 0.96) | 1.08 (0.87 to 1.34) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 0.90 (0.83 to 0.98) | 0.76 (0.63 to 0.91) | 0.94 (0.79 to 1.10) | 0.99 (0.85 to 1.15) | 0.86 (0.76 to 0.98) | 1.07 (0.86 to 1.33) |
| Continuing care needs | |||||||
| Any continuing care | 2645 (13.5) | 663 (13.5) | 116 (13.6) | 119 (12.9) | 143 (13.7) | 241 (14.9) | 44 (9.3) |
| Unadjusted OR (95% CI) | Ref. | 1.00 (0.91 to 1.09) | 1.01 (0.82 to 1.23) | 0.95 (0.78 to 1.15) | 1.02 (0.85 to 1.22) | 1.12 (0.97 to 1.29) | 0.66 (0.48 to 0.90) |
| Age and sex-adjusted OR (95% CI) | Ref. | 1.02 (0.92 to 1.13) | 1.02 (0.81 to 1.27) | 0.89 (0.72 to 1.11) | 1.13 (0.92 to 1.39) | 1.11 (0.95 to 1.30) | 0.71 (0.50 to 1.00) |
| Nursing home care | 485 (2.5) | 91 (1.9) | 11 (1.3) | 20 (2.2) | 19 (1.8) | 33 (2.0) | 8 (1.7) |
| Unadjusted OR (95% CI) | Ref. | 0.74 (0.59 to 0.93) | 0.51 (0.28 to 0.94) | 0.87 (0.44 to 1.37) | 0.73 (0.46 to 1.16) | 0.82 (0.57 to 1.17) | 0.68 (0.34 to 1.37) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 0.74 (0.59 to 0.94) | 0.51 (0.28 to 0.93) | 0.84 (0.53 to 1.33) | 0.78 (0.49 to 1.25) | 0.79 (0.55 to 1.14) | 0.75 (0.37 to 1.52) |
| Comorbidities | |||||||
| Atrial fibrillation | 2632 (13.5) | 538 (11.0) | 98 (11.5) | 89 (9.7) | 106 (10.2) | 202 (12.5) | 43 (9.1) |
| Unadjusted OR (95% CI) | Ref. | 0.75 (0.68 to 0.83) | 0.79 (0.63 to 0.98) | 0.68 (0.55 to 0.86) | 0.69 (0.56 to 0.85) | 0.84 (0.72 to 0.99) | 0.62 (0.45 to 0.86) |
| Age-and sex-adjusted OR (95% CI) | Ref. | 0.75 (0.67 to 0.83) | 0.78 (0.63 to 0.98) | 0.67 (0.53 to 0.84) | 0.72 (0.58 to 0.88) | 0.82 (0.70 to 0.96) | 0.66 (0.47 to 0.91) |
| Coronary artery disease | 275 (1.4) | 93 (1.9) | 15 (1.8) | 11 (1.2) | 14 (1.3) | 37 (2.3) | 16 (3.4) |
| Unadjusted OR (95% CI) | Ref. | 1.31 (1.03 to 1.66) | 1.21 (0.71 to 2.04) | 0.86 (0.47 to 1.57) | 0.92 (0.54 to 1.56) | 1.54 (1.08 to 2.18) | 2.44 (1.46 to 4.08) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 1.31 (1.03 to 1.66) | 1.21 (0.72 to 2.05) | 0.86 (0.47 to 1.57) | 0.93 (0.54 to 1.59) | 1.52 (1.08 to 2.16) | 2.43 (1.45 to 4.08) |
| Chronic kidney disease | 404 (2.1) | 91 (1.9) | 11 (1.3) | 14 (1.5) | 18 (1.7) | 41 (2.5) | 7 (1.5) |
| Unadjusted OR (95% CI) | Ref. | 0.86 (0.69 to 1.09) | 0.59 (0.32 to 1.08) | 0.74 (0.43 to 1.26) | 0.80 (0.50 to 1.30) | 1.15 (0.83 to 1.60) | 0.70 (0.33 to 1.49) |
| Age-and sex-adjusted OR (95% CI) | Ref. | 0.87 (0.69 to 1.09) | 0.60 (0.33 to 1.09) | 0.74 (0.43 to 1.26) | 0.82 (0.51 to 1.33) | 1.13 (0.82 to 1.57) | 0.72 (0.34 to 1.53) |
| Diabetes mellitus | 4298 (22.0) | 1157 (23.6) | 193 (22.7) | 213 (23.1) | 249 (23.9) | 398 (24.6) | 104 (22.1) |
| Unadjusted OR (95% CI) | Ref. | 1.05 (0.97 to 1.13) | 0.98 (0.83 to 1.17) | 1.09 (0.92 to 1.29) | 1.07 (0.92 to 1.25) | 1.07 (0.94 to 1.21) | 0.98 (0.78 to 1.24) |
| Age-and sex-adjusted OR (95% CI) | Ref. | 1.05 (0.97 to 1.13) | 0.99 (0.84 to 1.18) | 1.09 (0.92 to 1.29) | 1.07 (0.92 to 1.25) | 1.06 (0.94 to 1.20) | 0.97 (0.77 to 1.22) |
| Heart failure | 634 (3.2) | 155 (3.2) | 21 (2.5) | 29 (3.1) | 32 (3.1) | 55 (3.4) | 18 (3.8) |
| Unadjusted OR (95% CI) | Ref. | 0.94 (0.78 to 1.12) | 0.72 (0.46 to 1.12) | 0.98 (0.67 to 1.43) | 0.91 (0.64 to 1.31) | 0.98 (0.74 to 1.30) | 1.17 (0.72 to 1.89) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 0.94 (0.79 to 1.13) | 0.72 (0.46 to 1.12) | 0.98 (0.67 to 1.44) | 0.93 (0.65 to 1.34) | 0.97 (0.73 to 1.29) | 1.21 (0.75 to 1.95) |
| Hypertension | 9141 (46.8) | 2286 (46.7) | 389 (45.7) | 400 (43.4) | 478 (45.9) | 809 (50.1) | 210 (44.6) |
| Unadjusted OR (95% CI) | Ref. | 0.91 (0.84 to 0.97) | 0.85 (0.73 to 0.99) | 0.85 (0.73 to 0.99) | 0.88 (0.75 to 1.01) | 1.00 (0.89 to 1.12) | 0.85 (0.69 to 1.05) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 0.91 (0.84 to 0.98) | 0.84 (0.72 to 0.99) | 0.85 (0.73 to 0.99) | 0.90 (0.78 to 1.04) | 0.99 (0.88 to 1.11) | 0.88 (0.71 to 1.10) |
| Any comorbidity | 11 027 (56.5) | 2810 (57.3) | 488 (57.3) | 490 (53.2) | 584 (56.1) | 999 (61.8) | 249 (52.8) |
| Unadjusted OR (95% CI) | Ref. | 1.04 (0.97 to 1.10) | 1.03 (0.90 to 1.19) | 0.88 (0.77 to 1.00) | 0.99 (0.87 to 1.12) | 1.25 (1.12 to 1.39) | 0.86 (0.72 to 1.04) |
| Age- and sex-adjusted OR (95% CI) | Ref. | 1.03 (0.97 to 1.10) | 1.04 (0.90 to 1.19) | 0.88 (0.77 to 1.00) | 0.99 (0.87 to 1.12) | 1.25 (1.12 to 1.39) | 0.86 (0.72 to 1.04) |
| ≥ 2 comorbidities | 5184 (26.5) | 1244 (25.4) | 199 (23.4) | 228 (24.8) | 261 (25.1) | 441 (27.3) | 115 (24.4) |
| Unadjusted OR (95% CI) | Ref. | 0.94 (0.88 to 1.01) | 0.84 (0.72 to 0.99) | 0.91 (0.78 to 1.06) | 0.93 (0.80 to 1.07) | 1.04 (0.93 to 1.16) | 0.89 (0.72 to 1.11) |
| Age-and sex-adjusted OR (95% CI) | Ref. | 0.94 (0.87 to 1.01) | 0.84 (0.71 to 0.99) | 0.90 (0.77 to 1.05) | 0.94 (0.81 to 1.09) | 1.02 (0.91 to 1.14) | 0.91 (0.73 to 1.13) |
Note: CI = confidence interval, IQR = interquartile range, OR = odds ratio, Ref. = reference.
↵* Unless indicated otherwise.
↵† Wave 1 = Feb. 28, 2020 to May 12, 2020, lull period = May 13, 2020 to July 20, 2020, Wave 2.1 = July 21, 2020 to Oct. 11, 2020, Wave 2.2 = Oct. 12, 2020 to Feb. 15, 2021, Wave 3 = Feb. 16, 2021 to Mar. 31, 2021.