Table 1 Characteristics of ASD Cases and Controls (interviewed information versus information from birth certificate)a
Interviewed | Birth Certificate | |||
|---|---|---|---|---|
Characteristic | Cases (n = 217) | Controls (n = 226) | Cases (n = 216) | Controls (n = 4,971) |
N (%) | N (%) | N (%) | N (%) | |
Sex: | ||||
Male | 169 (77.9) | 175 (77.4) | 168 (77.8) | 3,980 (80.1) |
Female | 48 (22.1) | 51 (22.6) | 48 (22.2) | 991 (19.9) |
Year of birth – n(%) | ||||
2005 | 43 (19.8) | 53 (23.5) | 43 (20.0) | 1,153 (23.2) |
2006 | 59 (27.2) | 44 (19.5) | 59 (27.3) | 1,151 (23.2) |
2007 | 48 (22.1) | 46 (20.4) | 48 (22.2) | 1,066 (21.4) |
2008 | 37 (17.1) | 41 (18.1) | 36 (16.7) | 888 (17.9) |
2009 | 30 (13.8) | 42 (18.6) | 30 (13.9) | 713 (14.3) |
County at birth – n(%) | ||||
Allegheny | 131 (60.4) | 133 (58.8) | 129 (59.7) | 2,883 (58.0) |
Armstrong | 7 (3.2) | 2 (0.9) | 7 (3.2) | 151 (3.0) |
Beaver | 7 (3.2) | 18 (8.0) | 7 (3.2) | 393 (7.9) |
Butler | 17 (7.8) | 19 (8.4) | 18 (8.3) | 409 (8.2) |
Washington | 22 (10.1) | 24 (10.6) | 21 (9.7) | 448 (9.0) |
Westmoreland | 33 (15.2) | 30 (13.3) | 34 (15.7) | 687 (13.8) |
Maternal age (SD) – meanb | 30.4(5.4) | 31.8 (4.7) | 30.4 (5.4) | 28.5 (6.0) |
Paternal age (SD) – mean2 | 32.6 (6.0) | 33.6 (5.9) | 32.8 (5.8) | 31.4 (6.6) |
Mother raced | ||||
White | 194 (89.4) | 219 (96.9) | 196 (90.7) | 4,055 (81.9) |
Black | 15 (6.9) | 4 (1.8) | 16 (7.4) | 692 (14.0) |
Other | 2 (0.9) | 2 (0.9) | 4 (1.9) | 205 (4.1) |
Mother’s educatione | ||||
< High school graduate | 3 (1.4) | 2 (0.9) | 6 (2.8) | 475 (9.6) |
High school graduate and some college | 95 (43.8) | 46 (20.4) | 92 (42.6) | 2,536 (51.3) |
≥ College graduate | 119 (54.9) | 178 (78.7) | 118 (54.6) | 1,937 (39.2) |
Low birth weight (<2500 g)f,i (based on birth certificate) | 23 (10.7) | 9 (4.0) | 23 (10.6) | 341 (6.9) |
Preterm birth (< 37 weeks)g,j (based on birth certificate) | 31 (14.8) | 20 (9.0) | 31 (14.8) | 514 (10.6) |
Multiple births | 18 (8.4) | 9 (4.0) | 18 (8.4) | 189 (3.8) |
Maternal Smoking during pregnancy or in 3 months prior to pregnancyh | ||||
Yes | 54 (24.9) | 24 (10.6) | 30 (13.9) | 1,165 (23.9) |
No | 163 (75.1) | 202 (89.4) | 185 (86.0) | 3,714 (76.1) |