Table 3.
Characteristics comparing individuals who died or survived the follow-up period
| Died | Survived | |
| n | 6592 | 2 768 838 |
| Study individuals’ characteristics, n (%) | ||
| Asthma | ||
| Yes | 548 (8.3) | 260 774 (9.4) |
| No | 6044 (91.7) | 2 508 064 (90.6) |
| Sex | ||
| Male | 4079 (61.9) | 1 421 150 (51.3) |
| Female | 2513 (38.1) | 1 347 681 (48.7) |
| Prematurity | ||
| Yes (≤37 weeks) | 715 (10.9) | 165 571 (6.0) |
| No (>37 weeks) | 5877 (89.1) | 2 603 267 (94.0) |
| Small for gestational age | ||
| Yes | 381 (6.2) | 63 650 (2.3) |
| No | 5966 (91.0) | 2 622 298 (94.7) |
| Missing | 258 (3.8) | 82 890 (3.0) |
| Life-limiting condition | ||
| Yes | 970 (14.7) | 34 308 (1.2) |
| No | 5622 (85.3) | 2 734 530 (98.8) |
| Family characteristics | ||
| Maternal age at delivery, years | ||
| <20 | 253 (3.8) | 57 440 (2.0) |
| ≥20 to <25 | 1539 (23.4) | 464 273 (16.8) |
| ≥25 to <30 | 2235 (33.9) | 928 652 (33.5) |
| ≥30 to <35 | 1674 (25.4) | 856 648 (30.9) |
| ≥35 to <40 | 711 (10.8) | 382 386 (13.8) |
| ≥40 | 179 (2.7) | 77 937 (2.8) |
| Missing | 1 (<0.1) | 1502 (<0.1) |
| Maternal smoking during pregnancy | ||
| Yes | 1669 (25.3) | 393 871 (14.2) |
| No | 4456 (67.6) | 2 218 667 (80.1) |
| Missing | 467 (7.1) | 156 300 (5.6) |
| Maternal country of birth | ||
| Sweden | 5517 (83.7) | 2 286 702 (82.6) |
| Denmark, Norway, Finland, Iceland | 294 (4.5) | 75 822 (2.7) |
| Other | 780 (11.8) | 403 031 (14.6) |
| Missing | 1 (<0.1) | 3283 (0.12) |
| Parental income | ||
| Lowest | 1637 (24.8) | 531 983 (19.2) |
| Lower middle | 1294 (19.6) | 530 976 (19.2) |
| Middle | 1218 (18.4) | 531 564 (19.2) |
| Upper middle | 1122 (17.0) | 530 674 (19.2) |
| Highest | 1093 (16.6) | 530 774 (19.2) |
| Missing | 228 (3.6) | 112 867 (4.08) |
| Parental education | ||
| Compulsory school | 680 (10.3) | 176 485 (6.4) |
| High school | 3659 (55.5) | 1 253 475 (45.3) |
| College or further education | 1987 (30.1) | 1 207 980 (43.6) |
| Missing | 266 (4.1) | 130 898 (4.7) |