Table 1.
Descriptive characteristics of the study population (298 case-control pairs)
| Variables | Categories | ASD Cases N (%) |
TD Controls N (%) |
p- value a |
|---|---|---|---|---|
| Sex of child | Male | 246 (82.6) | 246 (82.6) | 1.00 |
|
| ||||
| Female | 52 (17.4) | 52 (17.4) | ||
|
| ||||
| Age of child at enrollment | < 48 months | 84 (28.2) | 76 (25.5) | 0.07 |
|
| ||||
| 48 – 71.9 months | 130 (43.6) | 143 (48.0) | ||
|
| ||||
| ≥ 72 months | 84 (28.2) | 79 (26.5) | ||
|
| ||||
| Race of child | Afro-Caribbean | 281 (94.3) | 291 (97.6) | 0.05 |
|
| ||||
| Other b | 17 (5.7) | 7 (2.4) | ||
|
| ||||
| Gestational age | Full term (≥ 37 weeks) | 263 (88.9) | 276 (92.6) | 0.15 |
|
| ||||
| Moderate to late preterm (32 – 36 weeks) | 24 (8.1) | 19 (6.4) | ||
|
| ||||
| Very to extremely preterm (< 32 weeks) | 9 (3.0) | 3 (1.0) | ||
|
| ||||
| Duration of breastfeedingc | < 3 months | 48 (16.1) | 52 (17.8) | 0.14 |
|
| ||||
| 3 – 5.9 months | 67 (22.6) | 68 (23.3) | ||
|
| ||||
| 6 – 15.9 months | 116 (39.1) | 90 (30.8) | ||
|
| ||||
| > 16 months | 66 (22.2) | 82 (28.1) | ||
|
| ||||
| Age of mother (at child’s birth) | < 35 years | 242 (81.2) | 262 (87.9) | 0.03 |
|
| ||||
| ≥ 35 years | 56 (18.8) | 36 (12.1) | ||
|
| ||||
| Age of father (at child’s birth) | < 35 years | 165 (55.4) | 216 (72.5) | <0.01 |
|
| ||||
| ≥ 35 years | 133 (44.6) | 82 (27.5) | ||
|
| ||||
| Race of mother | Afro-Caribbean | 285 (95.6) | 292 (98.0) | 0.12 |
|
| ||||
| Other b | 13 (4.4) | 6 (2.0) | ||
|
| ||||
| Race of fatherd | Afro-Caribbean | 281 (94.6) | 287 (97.3) | 0.10 |
|
| ||||
| Other b | 16 (5.4) | 8 (2.7) | ||
|
| ||||
| Mother’s education levele (at child’s birth) | Up to high school f | 149 (50.0) | 190 (64.4) | <0.01 |
|
| ||||
| Beyond high school g | 149 (50.0) | 105 (35.6) | ||
|
| ||||
| Father’s education levelh (at child’s birth) | Up to high school f | 168 (58.1) | 228 (80.6) | <0.01 |
|
| ||||
| Beyond high school g | 121 (41.9) | 55 (19.4) | ||
|
| ||||
| Relationship of parentsi | Relationship j | 206 (69.1) | 170 (57.8) | <0.01 |
|
| ||||
| No relationship k | 92 (30.9) | 124 (42.2) | ||
|
| ||||
| Parish of child’s birth | Kingston | 83 (27.8) | 188 (63.1) | <0.01 |
|
| ||||
| Other l | 215 (72.2) | 110 (36.9) | ||
|
| ||||
| High SES | Owns a car | 176 (59.1) | 119 (39.9) | <0.01 |
|
| ||||
| Does not own a car | 122 (40.9) | 179 (60.1) | ||
p-values based on Wald statistic from univariable conditional logistic regression;
Includes Asian-Indian and Mixed;
Data missing for 1 case and 6 controls;
Data missing for 1 case and 3 controls;
Data missing for 3 controls;
Includes never attended school, attended primary/junior-secondary, and secondary/high/technical school;
Includes attended HEART/vocational, tertiary college/university, and other tertiary school;
Data missing for 9 cases and 15 controls;
Data missing for 4 controls;
Includes visiting relationship, common law union, and married;
Includes divorced, separated, no relationship, and widowed;
Includes Portland, Trelawny, Westmoreland, Clarendon, St. Andrew, St. Mary, St. James, St. Elizabeth, St. Catherine, St. Thomas, St. Ann, Hanover, and Manchester parishes