Table 3.

Incidence rate ratios ADHD by NDVI within an exposure zone of $210\mathrm{m}\times 210\mathrm{m}$ and adjusted for $\mathrm{N}{\mathrm{O}}_{\mathrm{2}}$ and $\mathrm{P}{\mathrm{M}}_{\mathrm{2}\mathrm{.5}}$.

NDVIa deciles	Adjusted for $\mathrm{N}{\mathrm{O}}_{\mathrm{2}}$b IRR (95% CI)	Adjusted for $\mathrm{P}{\mathrm{M}}_{\mathrm{2}\mathrm{.5}}$c IRR (95% CI)
1	1.16 (1.09, 1.23)	1.19 (1.12, 1.27)
2	1.18 (1.11, 1.25)	1.20 (1.14, 1.28)
3	1.17 (1.10, 1.25)	1.19 (1.13, 1.26)
4	1.14 (1.07, 1.21)	1.16 (1.10, 1.23)
5	1.18 (1.12, 1.25)	1.20 (1.13, 1.27)
6	1.14 (1.08, 1.20)	1.15 (1.09, 1.22)
7	1.12 (1.05, 1.18)	1.13 (1.07, 1.19)
8	1.13 (1.07, 1.20)	1.14 (1.08, 1.21)
9	1.08 (1.02, 1.14)	1.09 (1.03, 1.15)
10	1.00 (ref)	1.00 (ref)
NDVId High vs. low	1.13 (1.07, 1.18)	1.15 (1.10, 1.21)
% explainede	21.28%	5.42%

Note: ADHD, attention deficit hyperactivity disorder; CI, confidence interval; IRR, incidence rate ratio; NDVI, normalized difference vegetation index; ${\mathrm{NO}}_2$, nitrogen dioxide; ${\mathrm{PM}}_{2.5}$, fine particulate matter.

^aMultilevel modeling was used to estimate the association between NDVI in deciles measured at $210\mathrm{m}\times 210\mathrm{m}$ around an individual’s residential address between age 0 to 5 y and the outcome of ADHD in a cohort of 814,689 individuals born in Denmark 1992–2007 and who were followed from 1997 until 2017.

^bAdjusted for age, calendar year, sex, mother’s and father’s level of education and income, urbanicity and proportion of low income, low education, and unemployment at municipal level and ${\mathrm{NO}}_2$.

^cAdjusted for age, calendar year, sex, mother’s and father’s level of education and income, urbanicity and proportion of low income, low education, and unemployment at municipal level and ${\mathrm{PM}}_{2.5}$.

^dMultilevel modeling was used to estimate the association between NDVI in deciles measured at $210\mathrm{m}\times 210\mathrm{m}$ around an individual’s residential address between age 0 to 5 y and the outcome of ADHD in a cohort of 814 689 individuals born in Denmark 1992–2007 and who were followed from 1997 until 2017.

^ePercentage of the association between NDVI and ADHD explained by air pollutant calculated as $[1-({\mathrm{\beta }}_{\mathrm{air}}/{\mathrm{\beta }}_{\mathrm{base}})]\times 100$.