Table 3.
Multivariate logistic regression evaluates the interaction of only-child status and pet ownership at different ages on the risk of ADHD.
| Only child | P for interaction | ||
|---|---|---|---|
| No | Yes | ||
| Overall | |||
| Pet ownership | |||
| No | 1.00 (reference) | 1.32 (1.24–1.40)*** | |
| Only during age 0–1 year | 1.59 (1.18–2.11)** | 2.00 (1.50–2.64)*** | 0.827 |
| Only during ages 1–3 years | 1.91 (1.48–2.45)*** | 1.52 (1.07–2.12)* | 0.020 |
| During both age ranges | 1.86 (1.52–2.27)*** | 1.83 (1.46–2.27)*** | 0.055 |
| Boys | |||
| Pet ownership | |||
| No | 1.0 (reference) | 1.35 (1.25–1.45)*** | |
| Only during age 0–1 year | 1.72 (1.16–2.46)** | 2.03 (1.40–2.87)*** | 0.622 |
| Only during ages 1–3 years | 1.81 (1.28–2.51)** | 1.76 (1.12–2.65)* | 0.239 |
| During both age ranges | 1.97 (1.52–2.52)*** | 1.89 (1.41–2.50)*** | 0.080 |
| Girls | |||
| Pet ownership | |||
| No | 1.00 (reference) | 1.28 (1.16–1.41)*** | |
| Only during age 0–1 year | 1.40 (0.84–2.18) | 2.01 (1.23–3.11)** | 0.726 |
| Only during ages 1–3 years | 2.06 (1.39–2.96)*** | 1.21 (0.64–2.08) | 0.028 |
| During both age ranges | 1.70 (1.20–2.35)** | 1.76 (1.22–2.47)** | 0.393 |
Adjusted for child age, maternal age, paternal age, maternal education, paternal education, marital status, household income, and family function score; in the overall model, child sex was additionally adjusted.
ADHD, attention-deficit/hyperactivity disorder. Bold values are significantly findings.