Table 1.
Birth and sociodemographic characteristics of the study population
| Characteristic | Cases (N=3,843) | Controls (N=38,430) | |||
|---|---|---|---|---|---|
| Mean / n | SD / % | Mean / n | SD / % | ||
| Maternal age at birth, years (Mean, SD) | 31.3 | 5.4 | 30.3 | 5.4 | |
| Paternal age at birth, years (Mean, SD) | 34.4 | 6.2 | 33.1 | 6.1 | |
| Gestational age at birth, weeks (Mean, SD) | 38.5 | 2.3 | 39.0 | 1.9 | |
| Sex, n (%) | Girls | 658 | 17 | 18,942 | 49 |
| Boys | 3185 | 83 | 19,488 | 51 | |
| Population group, n (%) | General population | 3,443 | 90 | 30,279 | 79 |
| Ultra-orthodox | 194 | 5 | 5,306 | 14 | |
| Israeli Arabs | 206 | 5 | 2,845 | 7 | |
| Socioeconomic index (sextiles), n (%) | Sextile 1(lowest) | 176 | 5 | 3,809 | 10 |
| Sextile 2 | 450 | 12 | 5,473 | 14 | |
| Sextile 3 | 622 | 16 | 5,474 | 14 | |
| Sextile 4 | 667 | 17 | 6,202 | 16 | |
| Sextile 5 | 890 | 23 | 7,393 | 19 | |
| Sextile 6 (highest) | 976 | 25 | 9,306 | 24 | |
| Missing | 62 | 2 | 773 | 2 | |
| Wage (USD/month), n (%) | Not Working | 370 | 10 | 5,047 | 13 |
| 0-1,500 | 620 | 16 | 7,412 | 19 | |
| 1,500-3,000 | 957 | 25 | 8,531 | 22 | |
| 3,000-4,000 | 756 | 20 | 6,471 | 17 | |
| 4,000+ | 1,140 | 30 | 10,969 | 29 | |
| Year of birth, n (%) | 2007 | 589 | 15 | 5,890 | 15 |
| 2008 | 633 | 16 | 6,330 | 16 | |
| 2009 | 723 | 19 | 7,230 | 19 | |
| 2010 | 742 | 19 | 7,420 | 19 | |
| 2011 | 657 | 17 | 6,570 | 17 | |
| 2012 | 499 | 13 | 4,990 | 13 | |
| Geocoding level, n(%) | House-level | 3,328 | 87 | 31,912 | 83 |
| Locality-level | 515 | 13 | 6,518 | 17 | |
Controls matched to cases by year of birth (10 controls per case). Percentages may not add up to 100 because of rounding. ASD = Autism spectrum disorder; IA = Israeli Arabs; UOJ = Ultra-orthodox Jews; GP = General population; Wage = household wage. converted by rate of US dollars (USD) 1 = NIS 4; socioeconomic index was measured at the census small statistical area level. SD indicates standard deviation.