Association of ADHD symptoms in adolescence and mortality in Northern Finland Birth Cohort 1986

Figures & data

Figure 1. Flowchart of the current study from the Northern Finland Birth Cohort 1986.

Figure 2. Cumulative mortality in the Northern Finland Birth Cohort 1986 follow-up sample.

Table 1. Demographics of the sample.

		Deceased during the follow-up
	Total	No		Yes
	n	n	%	n	%	P value
Sex	6685					<.001
Male (n = 3335)		3287	49.6	48	76.2
Female (n = 3350)		3335	50.4	15	23.8
Family structure	6542					.120
Other (n = 1485)		1466	77.4	19	31.7
Family with two biological parents (n = 5057)		5016	22.6	41	68.3
Lifetime cannabis use	5700					.014
No (n = 5378)		5339	94.4	39	84.8
Yes (n = 322)		315	5.6	7	15.2
Other lifetime substance use	5731					.24^a
No (n = 5520)		5477	96.3	43	93.5
Yes (n = 211)		208	3.7	3	6.5
Frequent alcohol intoxication past year	5614					.002
No (n = 4589)		4561	81.9	28	62.2
Yes (n = 1025)		1008	18.1	17	37.8
Parental psychiatric disorder	6685					.018
No (n = 4188)		4158	62.8	30	47.6
Yes (n = 2497)		2464	37.2	33	52.4
SWAN		Median	Q1/Q3	Median	Q1/Q3
Inattentive	6629	0.00	0.00/0.11	0.11	0.00/0.33
Hyperactive	6595	0.00	0.00/0.00	0.00	0.00/0.11
Combined	6547	0.00	0.00/0.11	0.056	0.00/0.17

SWAN: Strengths and Weaknesses of ADHD Symptoms and Normal Behaviors, Q1/Q3 = 25%/75% percentiles.

^aFisher’s exact test.

Table 2. Association of ADHD symptoms and mortality in Northern Finland Birth Cohort 1986.

SWAN category		SWAN inattentive				SWAN hyperactive				SWAN combined
	Sample size	Deaths	HR	95% CI	Sample size	Deaths	HR	95% CI	Sample size	Deaths	HR	95% CI
Mortality risk
Model 1	6629	63	2.30	1.46–3.63	6595	63	2.43	1.29–4.56	6547	63	2.67	1.57–4.61
Model 2	6486	60	1.96	1.19–3.24	6455	60	2.14	1.09–4.21	6407	60	2.29	1.26–4.17
Model 3	5423	44	1.15	0.53–2.50	5389	44	0.70	0.14–3.60	5357	44	1.02	0.33–3.15

Model 1: crude, Model 2: sex. family structure, parental psychiatric disorder, Model 3: Model 2, cannabis use, other lifetime substance use, frequent alcohol intoxication past year. Statistically significant results in bold. 95% CI: 95% confidence intervals; HR: hazard ratio; SWAN: Strengths and Weaknesses of ADHD symptoms and Normal Behaviors.

Data availability statement

NFBC data is available from the University of Oulu, Infrastructure for Population Studies. Permission to use the data can be applied for research purposes via electronic material request portal. In the use of data, we follow the EU general data protection regulation (679/2016) and Finnish Data Protection Act. The use of personal data is based on cohort participant’s written informed consent at his/her latest follow-up study, which may cause limitations to its use. Please contact NFBC project center ([email protected]) and visit the cohort website (www.oulu.fi/nfbc) for more information.