Table 3.

Comparison Between Smokers’ and Quitters’ Sibling Pair Groups

	First sibling			Second sibling			total
	n	%	per 1000	n	%	per 1000
Any psychiatric diagnosis
Quitters	1455	20.8	10.5	1546	22.1	11.3	6986
Smokers	3546	24.6	12.6	4107	28.5	15.0	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.81	0.75–0.86
Adjusted OR (95% CI)				1	0.77	0.72–0.83
Any psychiatric diagnosis in inpatient care
Quitters	494	7.1	3.4	568	8.1	4.0	6986
Smokers	1358	9.4	4.6	1553	10.8	5.3	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.73	0.66–0.81
Adjusted OR (95% CI)				1	0.82	0.74–0.91
Any psychiatric diagnosis in outpatient care
Quitters	1143	16.4	8.1	1450	20.8	10.5	6986
Smokers	2758	19.2	9.6	3889	27.0	14.0	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.83	0.77–0.89
Adjusted OR (95% CI)				1	0.77	0.71–0.82
Externalizing psychiatric diagnosis
Quitters	483	6.9	3.3	526	7.5	3.6	6986
Smokers	1400	9.7	4.6	1611	11.2	5.3	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.69	0.62–0.77
Adjusted OR (95% CI)				1	0.74	0.66–0.82
Externalizing psychiatric diagnosis in inpatient care
Quitters	64	0.9	0.4	51	0.7	0.3	6986
Smokers	220	1.5	0.7	156	1.1	0.5	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.60	0.45–0.79
Adjusted OR (95% CI)				1	0.79	0.57–1.09
Externalizing psychiatric diagnosis in outpatient care
Quitters	419	6.0	2.9	475	6.8	3.2	6986
Smokers	1180	8.2	3.9	1455	10.1	4.8	14 394
				The second sibling in smokers	The second sibling in quitters
Crude OR (95% CI)				1	0.71	0.64–0.80
Adjusted OR (95% CI)				1	0.74	0.66–0.82

CI = confidence interval; OR = odds ratio. Smoking in both pregnancies referred as smokers and smoking only in the first pregnancy as quitters.