Table 3.
Multivariable Binary Logistic Regression Analyses for Number of Siblings and Birth Order Predicting ADHD, Controlled for Age, Sex, Personal and Family History of Mood Disorders and Anxiety Disorders
| Model No. | Predictors | ADHD Screening Outcome | Multivariable Regression Analyses | |||
|---|---|---|---|---|---|---|
| No 1968 (61.14) | Yes 1251 (38.86) | OR | P-value | 95% CI | ||
| 1 | Number of siblings | |||||
| Single child | 12 (80.00) | 3 (20.00) | 0.38 | 0.14 | 0.10–1.38 | |
| One sibling | 40 (47.62) | 44 (52.38) | 1.70 | 0.01 | 1.09–2.64 | |
| Two or more siblings | 1916 (61.41) | 1204 (38.59) | Ref | |||
| 2 | Single child vs siblings | |||||
| Single child | 12 (80.00) | 3 (20.00) | 0.37 | 0.13 | 0.10–1.36 | |
| One or more siblings | 1956 (61.05) | 1248 (38.95) | Ref | |||
| 3 | Birth order including single child | |||||
| Single child | 12 (80.00) | 3 (20.00) | 0.40 | 0.16 | 0.11–1.44 | |
| First born | 463 (57.37) | 344 (42.63) | 1.22 | 0.02 | 1.02–1.47 | |
| Middle born | 640 (62.32) | 387 (37.68) | 1.01 | 0.88 | 0.85–1.19 | |
| Youngest born | 853 (62.26) | 517 (37.74) | Ref | |||
| 4 | Birth order (Siblings only)‡ | |||||
| First born | 463 (57.37) | 344 (42.63) | 1.22 | 0.02 | 1.02–1.47 | |
| Middle born | 640 (62.32) | 387 (37.68) | 1.01 | 0.89 | 0.85–1.19 | |
| Youngest born | 853 (62.26) | 517 (37.74) | Ref | |||
Note: ‡Excluded 15 students who had no siblings (n = 3204).