Prevalence and adjusted prevalence ratios of VTE among AIS patients with and without COVID-19 by demographic characteristics
| Variables | Total N (%) | AIS patients with hospitalised COVID-19 (N=13 873) | AIS patients with non-hospitalised COVID-19 (N=12 897) | AIS patients without COVID-19 (N=256 264) | P value* | PR (95% CI)† Hospitalised COVID-19 vs non-COVID-19 AIS | PR (95% CI)† Non-hospitalised COVID-19 vs non-COVID-19 AIS | |||
| No with VTE | Prevalence (95% CI) | No with VTE | Prevalence (95% CI) | No with VTE | Prevalence (95% CI) | |||||
| Total | 283 034 | 626 | 4.51 (4.18 to 4.87) | 382 | 2.96 (2.68 to 3.27) | 6697 | 2.61 (2.55 to 2.68) | <0.001 | 1.62 (1.54 to 1.70) | 1.13 (1.03 to 1.23) |
| Age in groups | ||||||||||
| 65–74 | 93 060 (32.9) | 231 | 5.39 (4.75 to 6.10) | 149 | 3.62 (3.09 to 4.23) | 2458 | 2.90 (2.79 to 3.02) | <0.001 | 1.69 (1.56 to 1.83) | 1.24 (1.08 to 1.40) |
| 75–84 | 106 608 (37.7) | 249 | 4.82 (4.27 to 5.44) | 122 | 2.54 (2.13 to 3.02) | 2603 | 2.69 (2.59 to 2.80) | <0.001 | 1.68 (1.55 to 1.81) | 0.94 (0.76 to 1.12) |
| 85+ | 83 366 (29.5) | 146 | 3.31 (2.82 to 3.88) | 111 | 2.79 (2.32 to 3.36) | 1636 | 2.18 (2.08 to 2.29) | <0.001 | 1.44 (1.27 to 1.60) | 1.27 (1.08 to 1.46) |
| Sex | ||||||||||
| Male | 125 356 (44.3) | 311 | 5.18 (4.65 to 5.77) | 160 | 2.91 (2.50 to 3.39) | 2915 | 2.56 (2.47 to 2.65) | <0.001 | 1.89 (1.77 to 2.00) | 1.13 (0.98 to 1.29) |
| Female | 157 678 (55.7) | 315 | 4.00 (3.59 to 4.46) | 222 | 3.00 (2.63 to 3.41) | 3782 | 2.66 (2.57 to 2.74) | <0.001 | 1.43 (1.31 to 1.54) | 1.13 (1.00 to 1.27) |
| Race/ethnicity | ||||||||||
| Non-Hispanic white | 230 539 (81.5) | 451 | 4.36 (3.98 to 4.77) | 313 | 2.99 (2.68 to 3.34) | 5211 | 2.48 (2.42 to 2.55) | <0.001 | 1.70 (1.61 to 1.80) | 1.21 (1.09 to 1.32) |
| Non-Hispanic black | 27 673 (9.8) | 125 | 6.53 (5.51 to 7.73) | 45 | 3.86 (2.89 to 5.14) | 976 | 3.97 (3.73 to 4.22) | <0.001 | 1.56 (1.37 to 1.74) | 0.95 (0.66 to 1.24) |
| Hispanic | 13 702 (4.8) | 32 | 2.94 (2.07 to 4.13) | 15 | 1.91 (1.13 to 3.15) | 310 | 2.62 (2.35 to 2.93) | 0.388 | 1.06 (0.70 to 1.42) | 0.72 (0.21 to 1.24) |
| Other race | 11 120 (3.9) | 18 | 3.41 (2.13 to 5.36) | 9 | 1.86 (0.93 to 3.56) | 200 | 1.98 (1.72 to 2.27) | 0.109 | 1.60 (1.11 to 2.08) | 0.93 (0.27 to 1.59) |
*P value comparing the difference in prevalence of VTE between the Medicare FFS beneficiaries hospitalised with AIS across three groups of COVID-19 status based on t-test.
†PRs were estimated using the log-binomial regression models adjusting for age, sex, race/ethnicity, NIHSS score, history of medical conditions and tobacco use.
AIS, acute ischaemic stroke; NIHSS, National Institutes of Health Stroke Scale; PR, prevalence ratio; VTE, venous thromboembolism.