Table 3.
Associations between long-term exposure to air pollution and risk of dementia in the older population of the Danish administrative cohort.
| Outcome | Air pollutant | Model1a HR (95 % CI) |
Model 2b HR (95 % CI) |
Model 3c HR (95 % CI) |
|---|---|---|---|---|
| Dementiad (81,731 cases among 934,792 subjects) | PM2⋅5 | 1⋅19 (1⋅17, 1⋅21) | 1⋅18 (1⋅16, 1⋅20) | 1⋅14 (1⋅12, 1⋅16) |
| NO2 | 1⋅20 (1⋅18, 1⋅23) | 1⋅20 (1⋅18, 1⋅23) | 1⋅25 (1⋅22, 1⋅28) | |
| BC | 1⋅23 (1⋅20, 1⋅25) | 1⋅23 (1⋅20, 1⋅25) | 1⋅23 (1⋅20, 1⋅26) |
Abbreviations: HR – Hazard ratio; CI – Confidence interval; PM2⋅5 – Particulate matter aerodynamic diameter < 2⋅5 µm; NO2 – Nitrogen dioxide; BC – Black carbon. Note: Results are presented as hazard ratio and 95 % confidence interval for the following interquartile range increments: 1⋅9 μg/m3 for PM2⋅5, 10⋅2 μg/m3 for NO2, and 0⋅5 × 10−5/m for black carbon.
Model 1 accounted for sex (strata) and parish levels(cluster term).
Model 2: Model 1 further adjusted for household income, employment status, immigrant status, marital status, and the highest level of education completed.
Model 3: Model 2 further adjusted for regional levels of average household income and unemployment rate, and the disparities of average household income and unemployment rate between parish and region
Dementia was defined based on records from hospitalisation and medication (see the Method part for details).