Table 4.
Comparison Between Nonsmokers’ and Starters’ Sibling Pair Groups
| First sibling | Second sibling | total | |||||
|---|---|---|---|---|---|---|---|
| n | % | per 1000 | n | % | per 1000 | ||
| Any psychiatric diagnosis | |||||||
| Starters | 1051 | 21.4 | 10.7 | 1224 | 24.9 | 12.5 | 4918 |
| Nonsmokers | 18 139 | 15.6 | 7.7 | 19 807 | 17.0 | 8.5 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 1.47 | 1.37–1.58 | ||||
| Adjusted OR (95% CI) | 1 | 1.39 | 1.30–1.49 | ||||
| Any psychiatric diagnosis in inpatient care | |||||||
| Starters | 379 | 7.7 | 3.7 | 470 | 9.6 | 4.6 | 4918 |
| Nonsmokers | 5683 | 4.9 | 2.3 | 6745 | 5.8 | 2.8 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 1.63 | 1.46–1.81 | ||||
| Adjusted OR (95% CI) | 1 | 1.40 | 1.27–1.55 | ||||
| Any psychiatric diagnosis in outpatient care | |||||||
| Starters | 846 | 17.2 | 8.5 | 1 157 | 23.5 | 11.9 | 4918 |
| Nonsmokers | 14 117 | 12.1 | 5.9 | 18 697 | 16.1 | 7.9 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 1.51 | 1.40–1.62 | ||||
| Adjusted OR (95% CI) | 1 | 1.38 | 1.29–1.48 | ||||
| Externalizing psychiatric diagnosis | |||||||
| Starters | 394 | 8.0 | 3.8 | 448 | 9.1 | 4.3 | 4918 |
| Nonsmokers | 4650 | 4.0 | 1.9 | 5127 | 4.4 | 2.1 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 2.09 | 1.88–2.33 | ||||
| Adjusted OR (95% CI) | 1 | 1.68 | 1.51–1.87 | ||||
| Externalizing psychiatric diagnosis in inpatient care | |||||||
| Starters | 61 | 1.2 | 0.6 | 51 | 1.0 | 0.5 | 4918 |
| Nonsmokers | 631 | 0.5 | 0.3 | 570 | 0.5 | 0.2 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 2.30 | 1.77–3.00 | ||||
| Adjusted OR (95% CI) | 1 | 1.66 | 1.23–2.24 | ||||
| Externalizing psychiatric diagnosis in outpatient care | |||||||
| Starters | 333 | 6.8 | 3.2 | 397 | 8.1 | 3.8 | 4918 |
| Nonsmokers | 4019 | 3.5 | 1.6 | 4557 | 3.9 | 1.8 | 116 391 |
| The second sibling in nonsmokers | The second sibling in starters | ||||||
| Crude OR (95% CI) | 1 | 2.03 | 1.81–2.28 | ||||
| Adjusted OR (95% CI) | 1 | 1.66 | 1.49–1.86 | ||||
CI = confidence interval; OR = odds ratio. “Smoking in neither pregnancy” referred as nonsmokers and “Smoking only in the second pregnancy” as starters.