Table 1.
Sample characteristics and air pollution exposures
| Covariates | ||
|---|---|---|
| Individual-level covariates | ||
| Age, years: mean (s.d.) | 41.6 | (19.4) |
| Gender, n (%) | ||
| Female | 8151 | (58.7) |
| Male | 5736 | (41.3) |
| Ethnicity, n (%) | ||
| Any other Asian background | 351 | (2.6) |
| Any other Black background | 1102 | (8.1) |
| Any other ethnic group | 1388 | (10.3) |
| Any other mixed background | 104 | (0.8) |
| Any other White background | 1289 | (9.5) |
| Bangladeshi | 63 | (0.5) |
| Black African | 1234 | (9.1) |
| Black Caribbean | 788 | (5.8) |
| Chinese | 86 | (0.6) |
| Indian | 174 | (1.3) |
| Irish | 320 | (2.4) |
| Pakistani | 116 | (0.9) |
| White and Asian | 25 | (0.2) |
| White and Black African | 57 | (0.4) |
| White and Black Caribbean | 172 | (1.3) |
| White British | 6269 | (46.3) |
| Marital status, n (%) | ||
| Cohabiting | 368 | (2.8) |
| Divorced | 287 | (2.2) |
| Divorced/civil partnership dissolved | 434 | (3.3) |
| Married | 1058 | (8.1) |
| Married/civil partner | 1596 | (12.3) |
| Separated | 665 | (5.1) |
| Single | 7640 | (58.8) |
| Widowed | 378 | (2.9) |
| Widowed/surviving civil partner | 575 | (4.4) |
| Area-level covariates, mean (s.d.)a | ||
| Ethnic density | 0.3 | (0.2) |
| Neighbourhood deprivation | 30.1 | (9.7) |
| Population density | 108.6 | (52.7) |
| Social fragmentation | 3.2 | (2.1) |
| Air pollution exposure, mean (s.d.), μg/m3b | ||
| NO2 | 40.5 | (10.1) |
| NOx | 71.7 | (26.2) |
| PM2.5 | 14.5 | (2.9) |
| PM10 | 21.6 | (4.2) |
NO2, nitrogen dioxide; NOx, nitrogen oxides; PM2.5, particulate matter with a diameter of <2.5 μm; PM10, particulate matter with a diameter of <10 μm.
a.
Units for area-level covariates: ethnic density, proportion of people residing in the same lower-layer super output area as the participant with the same ethnicity as the participant; neighbourhood deprivation, Index of Multiple Deprivation score; population density, persons per hectare; social fragmentation, z-scored composite of unmarried adults, single-person households, housing tenure and population turnover.
b.
Units for air pollution exposure: μg/m3.