Table 1.
Cohort composition in the full cohort and the gestational age sub-cohort, overall and by sex
| Full cohort | Gestational age sub-cohort | |||||
|---|---|---|---|---|---|---|
| All children | Male children | Female children | All children | Male children | Female children | |
| (N = 182,387) | (N = 93,321) | (N = 89,066) | (N = 113,154) | (N = 57,682) | (N = 55,472) | |
| Birth Season | ||||||
| Spring | 50,733 (27.8%) | 26,128 (28.0%) | 24,605 (27.6%) | 32,269 (28.5%) | 16,546 (28.7%) | 15,723 (28.3%) |
| Summer | 50,290 (27.6%) | 25,801 (27.6%) | 24,489 (27.5%) | 31,858 (28.2%) | 16,345 (28.4%) | 15,513 (28.0%) |
| Fall | 44,777 (24.6%) | 22,708 (24.3%) | 22,069 (24.8%) | 26,338 (23.3%) | 13,294 (23.1%) | 13,044 (23.5%) |
| Winter | 36,587 (20.1%) | 18,684 (20.0%) | 17,903 (20.1%) | 22,689 (20.1%) | 11,497 (20.0%) | 11,192 (20.2%) |
| Birth Year | ||||||
| 2010 | 25,031 (13.7%) | 12,513 (13.4%) | 12,518 (14.1%) | 15,391 (13.6%) | 7,614 (13.2%) | 7,777 (14.0%) |
| 2011 | 27,143 (14.9%) | 13,841 (14.8%) | 13,302 (14.9%) | 18,203 (16.1%) | 9,225 (16.0%) | 8,978 (16.2%) |
| 2012 | 32,721 (17.9%) | 16,736 (17.9%) | 15,985 (17.9%) | 23,127 (20.4%) | 11,780 (20.5%) | 11,347 (20.5%) |
| 2013 | 32,438 (17.8%) | 16,686 (17.9%) | 15,752 (17.7%) | 23,343 (20.6%) | 11,924 (20.7%) | 11,419 (20.6%) |
| 2014 | 27,543 (15.1%) | 14,196 (15.2%) | 13,347 (15.0%) | 21,279 (18.8%) | 11,003 (19.1%) | 10,276 (18.5%) |
| 2015 | 18,933 (10.4%) | 9,833 (10.5%) | 9,100 (10.2%) | 11,811 (10.4%) | 6,136 (10.7%) | 5,675 (10.2%) |
| 2016 | 18,578 (10.2%) | 9,516 (10.2%) | 9,062 (10.2%) | - | - | - |
| Gestational Age | ||||||
| less than 28 wks | 449 (0.2%) | 237 (0.3%) | 212 (0.2%) | 449 (0.4%) | 237 (0.4%) | 212 (0.4%) |
| 28 to 36 wks | 8,433 (4.6%) | 4,396 (4.7%) | 4,037 (4.5%) | 8,433 (7.5%) | 4,396 (7.6%) | 4,037 (7.3%) |
| greater than 36 wks | 104,216 (57.1%) | 53,049 (56.8%) | 51,223 (57.5%) | 104,216 (92.1%) | 53,049 (92.1%) | 51,223 (92.3%) |
| missing | 69,289 (38%) | 35,639 (38.2%) | 33,594 (37.7%) | - | - | - |
| Upper respiratory medication claim | ||||||
| No | 179,939 (98.7%) | 91,935 (98.5%) | 88,004 (98.8%) | 111,752 (98.8%) | 56,880 (98.8%) | 54,872 (98.9%) |
| Yes | 2,448 (1.3%) | 1,386 (1.5%) | 1,062 (1.2%) | 1,402 (1.2%) | 802 (1.4%) | 600 (1.1%) |
| Lower respiratory medication claim | ||||||
| No | 148,646 (81.5%) | 73,668 (78.9%) | 74,978 (84.2%) | 92,707 (81.9%) | 45,810 (79.6%) | 46,897 (84.5%) |
| Yes | 33,741 (18.5%) | 19,653 (21.1%) | 14,088 (15.8%) | 20,447 (18.1%) | 11,872 (20.6%) | 8,575 (15.5%) |
| Systemic anti-inflammatory medication claim | ||||||
| No | 158,348 (86.8%) | 79,068 (84.7%) | 79,280 (89.0%) | 98,549 (87.1%) | 49,048 (85.2%) | 49,501 (89.2%) |
| Yes | 24,039 (13.2%) | 14,253 (15.3%) | 9,786 (11%) | 14,605 (12.9%) | 8,634 (15%) | 5,971 (10.8%) |