Table 2 The HRs and 95% CIs for the association between combined air pollutants exposure and the risk of incident cognitive impairment and dementia, adjusted by potential confounders

All-cause dementia

 Case/person-years

1230/1,154,625

1384/1,150,136

1465/1,144,651

1459/1,142,135

1458/1,147,265

 Model1

Reference

1.15 (1.06–1.24)

1.26 (1.17–1.36)

1.34 (1.24–1.44)

1.45 (1.34–1.56)

2.71295E-25

 Model2

Reference

1.08 (1–1.17)

1.15 (1.06–1.24)

1.19 (1.1–1.29)

1.26 (1.17–1.36)

2.46186E-10

 Model3

Reference

1.07 (0.99–1.15)

1.13 (1.05–1.22)

1.16 (1.08–1.25)

1.21 (1.12–1.31)

1.02076E-07

Alzheimer’s dementia

 Case/person-years

530/1,156,231

598/1,151,669

581/1,146,771

590/1,144,482

628/1,149,591

 Model1

Reference

1.15 (1.02–1.29)

1.16 (1.03–1.3)

1.26 (1.12–1.41)

1.45 (1.29–1.63)

2.31653E-10

 Model2

Reference

1.09 (0.97–1.22)

1.07 (0.95–1.2)

1.14 (1.01–1.28)

1.3 (1.15–1.46)

2.88284E-05

 Model3

Reference

1.09 (0.97–1.22)

1.06 (0.95–1.2)

1.13 (1–1.27)

1.28 (1.14–1.44)

8.42853E-05

Vascular dementia

 Case/person-years

244/1,156,781

313/1,152,836

328/1,147,997

321/1,145,401

338/1,149,376

 Model1

Reference

1.3 (1.1–1.53)

1.43 (1.21–1.69)

1.48 (1.26–1.75)

1.68 (1.43–1.98)

3.39876E-10

 Model2

Reference

1.21 (1.02–1.43)

1.27 (1.07–1.5)

1.29 (1.09–1.52)

1.41 (1.19–1.66)

0.000113222

 Model3

Reference

1.18 (0.99–1.39)

1.22 (1.04–1.45)

1.21 (1.03–1.44)

1.3 (1.1–1.54)

0.004549959

MCI

 Case/person-years

126/1,156,762

143/1,152,707

153/1,148,090

192/1,145,912

230/1,149,732

 Model1

Reference

1.15 (0.91–1.46)

1.28 (1.01–1.62)

1.69 (1.35–2.11)

2.13 (1.72–2.65)

4.45858E-15

 Model2

Reference

1.09 (0.86–1.39)

1.16 (0.92–1.47)

1.49 (1.19–1.88)

1.79 (1.44–2.24)

1.63128E-09

 Model3

Reference

1.07 (0.84–1.36)

1.14 (0.9–1.44)

1.44 (1.15–1.81)

1.71 (1.37–2.14)

2.34471E-08