. 2020 Dec 22;128(12):127011. doi: 10.1289/EHP6729

Table 1.

Distribution of 29,697 cases of ADHD and 9,770,746 person-years at risk in the overall cohort.

	Number of cases with ADHD	Number of person-years at risk in total in the cohort	Incidence rate per 10,000 person-years
Year of birth
1992–1996	10,253	4,682,352.47	21.9
1997–2001	10,655	3,096,788.89	34.4
2002–2007	8,789	1,991,604.54	44.1
Sex
Male	20,420	4,973,694.16	41.1
Female	9,277	4,797,051.74	19.3
Region in Denmark
North Denmark	2,751	1,102,336.62	25.0
Central Denmark	8,112	2,363,555.83	34.3
South Denmark	5,667	2,215,020.19	25.6
Capital region	8,591	2,707,981.79	31.7
Zealand	4,576	1,381,851.48	33.1
Degree of urbanization at birth^a
Capital	3,171	1,136,790.33	27.9
Capital suburb	4,010	1,201,872.57	33.4
Municipalities with a town with $> 100,000$ inhabitants	2,966	1,171,198.67	25.3
Municipalities with a town with 10,000–100,000 inhabitants	8,893	2,773,159.44	32.1
Other municipalities (largest town $< 10,000$ inhabitants)	10,621	3,481,479.72	30.5
Missing	36	6,245.17	90
Mother’s level of education^a
Primary school	11,409	2,169,404.59	52.6
Short education	13,463	4,947,213.78	27.2
Medium long education	3,908	2,036,361.2	19.2
Long education	720	580,955.64	12.4
Missing	197	36,810.71	53.5
Father’s level of education^a
Primary school	10,919	2,124,245.83	51.4
Short education	15,169	5,540,432.09	27.4
Medium long education	1,954	1,171,251.65	16.7
Long education	1,049	832,717.29	12.6
Missing	606	102,099.03	59.3
Mother’s level of income^b
Below the 20th percentile	824	194,441.59	42.4
20th to the 40th percentile	4,393	839,004.45	52.4
40th to the 60th percentile	14,085	3,752,154.26	37.5
60th to the 80th percentile	8,497	3,773,234.86	22.5
Above the 80th percentile	1,898	1,211,910.73	15.7
Father’s level of income^b
Below the 20th percentile	585	113,376.48	51.6
20th to the 40th percentile	2,207	391,452.09	56.4
40th to the 60th percentile	4,892	982,753.53	49.8
60th to the 80th percentile	10,990	3,187,737.30	34.5
Above the 80th percentile	11,002	5,092,107.37	21.6
Missing	21	3,319.14	63.3
Accumulated mean NDVI ( $210 m \times 210 m$ ) in deciles
1st decile (−0,588142–0,162019)	3,413	1,181,692.12	28.9
2nd decile (0,1625203–0,2542293)	3,227	1,116,921.65	28.9
3rd decile (0,2542301–0,3145785)	3,115	1,057,289.32	29.5
4th decile (0,3145791–0,3618568)	2,989	998,719.91	29.92
5th decile (0,3618578–0,4039548)	3,048	953,622.57	32.0
6th decile (0,4039552–0,4422902)	2,931	911,696.23	32.1
7th decile (0,4422906–0,4770624)	2,828	870,574.88	32.5
8th decile (0,4770632–0,5123291)	2,881	863,872.45	33.3
9th decile (0,5123299–0,5561148)	2,761	888,147.35	31.1
10th decile (0,5561150–0,7973234)	2,504	928,209.42	27.0

Note: Cohort consisted of 814,689 children born 1992–2007. ADHD, attention deficit hyperactivity disorder; NDVI, normalized difference vegetation index.

^{^a}

Highest finished education measured at the end of the year of the child’s birth.

^{^b}

Level of income at the year of the child’s birth.