Table 1.
Distribution [n (%)] of selected sociodemographic variables; leukemia cases and controls, children < 2 years of age, Brazil, 1999–2007.
| Characteristic | Cases (n = 252) | Controls (n = 423) | p-Value |
|---|---|---|---|
| Sex | |||
| Male | 130 (51.6) | 226 (53.4) | 0.643 |
| Female | 122 (48.4) | 197 (46.6) | |
| Missing | 0 | 0 | |
| Birth weight | |||
| < 4,000 g | 234 (92.9) | 393 (93.0) | 0.470 |
| ≥ 4,000 g | 16 (6.3) | 21 (5.0) | |
| Missing | 2 (0.8) | 9 (2.0) | |
| Child’s skin color | |||
| White | 170 (67.5) | 153 (36.2) | < 0.001 |
| Nonwhite | 77 (30.5) | 256 (60.5) | |
| Missing | 5 (2.0) | 14 (3.3) | |
| Place of birth | |||
| Northeast | 52 (20.6) | 101 (24.1) | 0.552 |
| Midwest | 18 (7.1) | 31 (7.3) | |
| Southeast | 155 (61.5) | 237 (56.0) | |
| South | 27 (10.7) | 54 (12.6) | |
| Missing | 0 | 0 | |
| Maternal age (years)a | |||
| < 18 | 8 (3.2) | 60 (14.1) | < 0.001 |
| 18–24 | 91 (36.1) | 182 (42.9) | |
| 25–34 | 117 (46.4) | 145 (34.2) | |
| > 35 | 36 (14.3) | 36 (8.8) | |
| Missing | 0 | 0 | |
| Maternal education (years) | |||
| ≤ 8 | 81 (32.1) | 206 (48.6) | < 0.001 |
| > 8 | 146 (57.9) | 209 (49.4) | |
| Missing | 25 (10.0) | 8 (2.0) | |
| Family income (Brazilian real) | |||
| ≤ 350 | 74 (29.4) | 148 (35.0) | < 0.001 |
| 351–1,750 | 102 (40.5) | 218 (51.5) | |
| 1,751–3,500 | 27 (10.7) | 11 (2.6) | |
| ≥ 3,500 | 12 (5.0) | 3 (0.7) | |
| Missing | 37 (14.4) | 43 (10.2) | |
| Oral contraceptive use | |||
| No | 223 (88.5) | 404 (95.5) | < 0.001 |
| Yes | 29 (11.5) | 19 (4.5) | |
| Missing | 0 | 0 | |
| aMaternal age at birth. | |||