Appendix Case cross over comparison of patients' usual frequency of vigorous physical activity with presence of vigorous physical activity during hazard period—namely, the 15 minutes before the onset of the subarachnoid haemorrhage
| Number of cases with vigorous physical activity during hazard period | 4 |
|---|---|
| Algebraic sum of 15 minute blocks of non-vigorous or no physical activity over the prior year in patients who reported vigorous physical activity during hazard period (numerator) | 138591 |
| Algebraic sum of 15 minute blocks of vigorous physical activity over the prior year in patients who did not report vigorous physical activity during hazard period (denominator) | 9226 |
| Relative risk (95% confidence interval)4-150 | 15.0 (4.3–52.2) |
↵4-150 Mantel-Haenszel estimate of the relative risk of having a subarachnoid haemorrhage during a period of vigorous physical activity compared with a period of non-vigorous or no physical activity.