Asthma severity algorithm | Acute asthma | ||||
No asthma | Diagnosis only or intermittent bronchodilator | Persistent mild* | Persistent moderate or severe | Inpatient hospital admission† | |
N | 75 156 | 2839 | 6247 | 1664 | 3487 |
Sex=male (%) | 37 906 (50) | 1624 (57) | 3767 (60) | 1026 (62) | 2284 (66) |
Gestation at birth‡ | |||||
≤32 | 990 (1) | 73 (3) | 180 (3) | 56 (3) | 152 (4) |
33–36 | 3974 (5) | 173 (6) | 390 (6) | 131 (8) | 245 (7) |
37+ weeks | 65 870 (88) | 2429 (86) | 5339 (86) | 1389 (84) | 2913 (84) |
Small for gestational birth (<10th centile)‡=yes (%) | 6474 (9) | 272 (10) | 578 (9) | 141 (9) | 337 (10) |
Parity ≥1 | 43 284 (58) | 1564 (55) | 3572 (57) | 947 (57) | 2079 (60) |
Congenital anomaly§=Yes (%) | 3516 (5) | 187 (7) | 373 (6) | 115 (7) | 273 (8) |
Maternal age at childbirth | |||||
<18 (%) | 1956 (3) | 119 (4) | 163 (3) | 37 (2) | 125 (4) |
18–24 (%) | 18 713 (25) | 878 (31) | 1857 (30) | 502 (30) | 1126 (32) |
25–29 years (%) | 21 072 (28) | 802 (28) | 1776 (28) | 470 (28) | 947 (27) |
30–34 (%) | 21 750 (29) | 696 (25) | 1622 (26) | 434 (26) | 868 (25) |
35+ (%) | 11 627 (16) | 343 (12) | 826 (13) | 219 (13) | 420 (12) |
Breast feeding¶ | |||||
No (%) | 28 242 (38) | 1138 (40) | 2602 (42) | 716 (43) | 1540 (44) |
Yes (%) | 31 996 (43) | 1054 (37) | 2282 (37) | 661 (40) | 1318 (38) |
NA (%) | 14 918 (20) | 647 (23) | 1363 (22) | 287 (17) | 629 (18) |
Maternal smoking in first trimester | |||||
No (%) | 18 493 (25) | 622 (22) | 1351 (22) | 382 (23) | 729 (21) |
Yes (%) | 5448 (7) | 243 (9) | 491 (8) | 130 (8) | 308 (9) |
NA (%) | 51 215 (68) | 1974 (70) | 4405 (70) | 1152 (69) | 2450 (70) |
Townsend deprivation quintile at birth | |||||
1—least (%) | 13 723 (18) | 424 (15) | 920 (15) | 218 (13) | 460 (13) |
2 (%) | 14 745 (20) | 466 (16) | 1102 (18) | 307 (18) | 593 (17) |
3 (%) | 15 171 (20) | 561 (20) | 1244 (20) | 340 (20) | 676 (19) |
4 (%) | 15 414 (21) | 609 (22) | 1414 (23) | 390 (23) | 824 (24) |
5—most (%) | 15 884 (21) | 768 (27) | 1547 (25) | 403 (24) | 921 (26) |
Free school meals eligible**=yes (%) | 12 299 (16) | 643 (23) | 1270 (20) | 338 (20) | 796 (23) |
School absence percentage†† | |||||
<5 (%) | 19 867 (48) | 608 (41) | 1254 (39) | 297 (31) | 624 (33) |
5–9 (%) | 12 776 (31) | 476 (32) | 1162 (36) | 332 (35) | 679 (36) |
10–14 (%) | 4473 (11) | 196 (13) | 462 (14) | 174 (18) | 300 (16) |
15–19 (%) | 1533 (4) | 75 (5) | 141 (4) | 70 (7) | 117 (6) |
20+ (%) | 922 (2) | 60 (4) | 111 (3) | 44 (5) | 92 (5) |
NA (%) | 1479 (4) | 73 (5) | 117 (4) | 38 (4) | 83 (4) |
*Inhaled corticosteroid or alternative.
†Excludes first admission if before first GP visit.
‡6% missing data evenly found across asthma groups.
§Major or minor.
¶At birth or 6–8 weeks.
**In Key Stage 1 (KS1), assessment year as a proxy for level of deprivation beyond birth.
††In school year when KS1 was taken where assessment usually starts in the final 2½ months, subsample due to availability of school absence data, births between September 2000 and August 2004, N=46 470.