Table 2.

Incidence rate ratios (IRRs) for ADHD by NDVI within an exposure zone of $210\mathrm{m}\times 210\mathrm{m}$ and in different adjustment models.

NDVIa deciles	Base adjustmentb IRR (95% CI)	Base adjustment and individual SESc IRR (95% CI)	Base adjustment, individual- and neighborhood-level SESd IRR (95% CI)	Base adjustment, individual and neighborhood-level SES and urbanicitye IRR (95% CI)
1	1.55 (1.46, 1.65)	1.21 (1.14, 1.28)	1.20 (1.13, 1.28)	1.20 (1.13, 1.28)
2	1.46 (1.38, 1.55)	1.21 (1.14, 1.29)	1.21 (1.15, 1.29)	1.21 (1.15, 1.29)
3	1.40 (1.33, 1.48)	1.20 (1.13, 1.27)	1.20 (1.14, 1.27)	1.20 (1.14, 1.27)
4	1.34 (1.26, 1.41)	1.16 (1.10, 1.23)	1.17 (1.10, 1.24)	1.17 (1.10, 1.24)
5	1.35 (1.28, 1.42)	1.20 (1.14, 1.27)	1.21 (1.14, 1.28)	1.21 (1.14, 1.28)
6	1.29 (1.22, 1.36)	1.16 (1.10, 1.23)	1.16 (1.10, 1.23)	1.16 (1.10, 1.23)
7	1.24 (1.17, 1.31)	1.13 (1.07, 1.20)	1.13 (1.07, 1.20)	1.13 (1.07, 1.20)
8	1.23 (1.17, 1.30)	1.14 (1.08, 1.21)	1.15 (1.08, 1.21)	1.15 (1.08, 1.21)
9	1.15 (1.09, 1.21)	1.09 (1.03, 1.15)	1.09 (1.03, 1.15)	1.09 (1.03, 1.15)
10	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)
NDVIf High vs. low	1.43 (1.37, 1.49)	1.16 (1.11, 1.22)	1.16 (1.11, 1.22)	1.16 (1.11, 1.22)
Per 0.1 NDVI decrease	1.07 (1,06, 1.07)	1.03 (1.02, 1.03)	1.03 (1.02, 1.03)	1.03 (1.02, 1.03)

Note: ADHD, attention deficit hyperactivity disorder; CI, confidence interval; IRR; incidence rate ratio; NDVI, normalized difference vegetation index; SES, socioeconomic status.

^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 and 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, and sex.

^cAdjusted for age, calendar year, sex, and mother’s and father’s level of education and income.

^dAdjusted for age, calendar year, sex and proportion of low income, low education, and unemployment at municipal level.

^eAdjusted 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.

^fMultilevel modeling was used to estimate the association between NDVI as numeric deciles measured at $210\mathrm{m}\times 210\mathrm{m}$ around an individual’s residential address between age 0 and 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.