Age- and season-adjusted incidence ratio (IR) for first myocardial infarction and first stroke after influenza and all other respiratory viruses (combined) compared with baseline time periods
| Time period after sample days | IR for influenza virus (95% CI) | p-value | IR for other respiratory viruses (95% CI) | p-value |
| Outcome: myocardial infarction# | ||||
| 1–3 | 9.80 (2.37–40.5) | 0.002 | 2.81 (0.39–20.3) | 0.31 |
| 4–7 | 3.98 (0.55–28.9) | 0.17 | 2.30 (0.32–16.6) | 0.41 |
| 8–14 | 2.72 (0.38–19.5) | 0.32 | ∼0 | 0.98 |
| 15–28 | 2.77 (0.68–11.2) | 0.15 | 1.58 (0.39–6.41) | 0.64 |
| Baseline | 1.00 | 1.00 | ||
| Outcome: stroke¶ | ||||
| 1–3 | 7.82 (1.07–56.9) | 0.042 | 4.86 (0.67–35.4) | 0.12 |
| 4–7 | ∼0 | 0.99 | 8.72 (2.14–35.6) | 0.003 |
| 8–14 | 8.13 (1.98–33.3) | 0.004 | 2.35 (0.32–17.0) | 0.40 |
| 15–28 | 5.13 (1.55–17.0) | 0.007 | 2.59 (0.63–10.6) | 0.19 |
| Baseline | 1.00 | 1.00 |
#: n=1227; ¶: n=762.