Change in the incidence of hospital admissions and presentations, and of acute therapies for ischemic stroke during the first year of the COVID-19 pandemic (Feb. 28, 2020 to Mar. 31, 2021), compared with before the pandemic (Jan. 1, 2016 to Feb. 27, 2020) in Alberta, Canada
| Metric | Prepandemic period‡ | Pandemic periods* | ||||
|---|---|---|---|---|---|---|
| Wave 1 | Lull | Wave 2.1 | Wave 2.2 | Wave 3 | ||
| Hospital admissions and presentations for ischemic stroke, median weekly incidence per 100 000 people | 2.11 | 1.81 | 2.02 | 1.90 | 1.95 | 1.65 |
| Weekly IRR (95% CI)† | Ref. | 0.54 (0.50 to 0.59) | 0.52 (0.48 to 0.56) | 0.50 (0.46 to 0.53) | 0.47 (0.45 to 0.50) | 0.45 (0.41 to 0.50) |
| Monthly IRR† | Ref. | 0.51 (0.47 to 0.55) | 0.48 (0.45 to 0.52) | 0.46 (0.43 to 0.49) | 0.43 (0.41 to 0.46) | 0.42 (0.37 to 0.46) |
| Quarterly IRR† | Ref. | 0.52 (0.48 to 0.56) | 0.49 (0.46 to 0.53) | 0.47 (0.44 to 0.51) | 0.44 (0.42 to 0.47) | 0.43 (0.39 to 0.48) |
| Thrombolysis for ischemic stroke, median weekly incidence per 100 000 people | 0.25 | 0.21 | 0.24 | 0.21 | 0.21 | 0.18 |
| Weekly IRR† | Ref. | 0.50 (0.41 to 0.62) | 0.47 (0.38 to 0.58) | 0.47 (0.39 to 0.56) | 0.41 (0.35 to 0.48) | 0.44 (0.34 to 0.58) |
| Monthly IRR† | Ref. | 0.50 (0.41 to 0.62) | 0.47 (0.38 to 0.59) | 0.47 (0.39 to 0.57) | 0.41 (0.35 to 0.48) | 0.44 (0.34 to 0.58) |
| Quarterly IRR† | Ref. | 0.51 (0.42 to 0.63) | 0.48 (0.39 to 0.60) | 0.48 (0.40 to 0.58) | 0.42 (0.36 to 0.49) | 0.46 (0.35 to 0.60) |
| Endovascular therapy for ischemic stroke, median weekly incidence per 100 000 people | 0.12 | 0.12 | 0.13 | 0.10 | 0.12 | 0.07 |
| Weekly IRR† | Ref. | 0.63 (0.47 to 0.84) | 0.56 (0.43 to 0.74) | 0.52 (0.40 to 0.68) | 0.49 (0.40 to 0.60) | 0.31 (0.19 to 0.51) |
| Monthly IRR† | Ref. | 0.64 (0.47 to 0.85) | 0.57 (0.43 to 0.75) | 0.53 (0.40 to 0.69) | 0.50 (0.40 to 0.61) | 0.32 (0.20 to 0.51) |
| Quarterly IRR† | Ref. | 0.65 (0.48 to 0.87) | 0.58 (0.44 to 0.77) | 0.54 (0.41 to 0.70) | 0.50 (0.41 to 0.62) | 0.33 (0.20 to 0.53) |
Note: CI = confidence interval, IRR = incidence rate ratio, Ref. = reference.
↵* 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.
↵† Adjusted for age, sex, preadmission continuing care needs and comorbidities.
↵‡ The median weekly incidence of hospital admissions and presentations, thrombolysis and endovascular therapy was 2.12, 0.26 and 0.15 per 100 000 people, respectively, in the last 3 months of the prepandemic period.