Table 2.
Baseline Characteristics of Cases of Aneurismal Subarachnoid Hemorrhage and Controls in Wales Between 2000 and 2019
| Cases | Controls | |
| N | 4,879 | 43,911 |
| Matching criteria | ||
| Observation period, d, median (range) | 3,554 (365–7,304) | 3,550 (365–7,304) |
| Age,a mean (SD) | 61.4 (15.4) | 61.4 (15.4) |
| Female,a n (%) | 2,988 (61.2) | 26,892 (61.2) |
| Smoking status, n (%) | ||
| Current | 1,787 (37) | 9,005 (21) |
| Former | 978 (20) | 9,511 (22) |
| Never | 1,840 (38) | 22,413 (51) |
| Other | ||
| Hypertension, n (%) | 2,030 (42) | 16,335 (37) |
| No. of general practitioner consultations, mean (SD) | 23.3 (20.0) | 18.9 (17.4) |
| Deprivation index, mean (SD) | 22.4 (15.7) | 20.9 (15.1) |
| Alcohol abuse, n (%) | 333 (7) | 1,784 (4) |
| BMI, mean (SD) | 26.9 (5.6) | 27.6 (5.8) |
| Modified Elixhauser score, mean (SD) | 1.8 (1.7) | 1.4 (1.6) |
Abbreviation: BMI = body mass index.
a
Matching criteria for nested-case control. Reported values at baseline (i.e., index date).