Summary statistics of sample, US Health and Retirement Study, 2006
| Variables | Mean (SD) | % |
| Outcome | ||
| Cognitive function (range: 0–27) | 16.1 (4.3) | |
| Exposure | ||
| High exposure to extreme heat* | 17.3 | |
| Subgroups | ||
| Race/ethnicity | ||
| Non-Hispanic white | 83.3 | |
| Non-Hispanic black | 9.3 | |
| Hispanic | 7.4 | |
| Neighbourhood SES† | ||
| Average neighbourhood | 70.5 | |
| Disadvantaged neighbourhood | 11.6 | |
| Affluent neighbourhood | 17.9 | |
| Covariates | ||
| Age in years (range: 52–104) | 65.0 (9.5) | |
| Female sex | 54.8 | |
| Living alone, not married/partnered | 19.6 | |
| ≥ Some college education | 49.2 | |
| Household wealth | $377K ($1099K) | |
| Region | ||
| Northeast | 18.0 | |
| Midwest | 26.7 | |
| South | 37.7 | |
| West | 17.7 | |
| Urbanicity | 76.2 | |
| Years of follow-up (range: 2–12) | 9.3 (3.5) |
*Exposure to extreme heat was measured as the average number of extreme heat days per year during the participant’s follow-up period, up to the year preceding their last cognitive assessment. High exposure was defined as a level that falls within the highest quintile, which corresponds to 13.1 or more days of extreme heat.
†Disadvantaged neighbourhoods refer to census tracts scoring 1 SD above the average on a composite index of area socioeconomic disadvantages (eg, % residents living in poverty). Affluent neighbourhoods are defined as census tracts scoring 1 SD above the mean on a composite index of socioeconomic advantages (eg, % residents with college education). Average neighbourhoods include all other census tracts not classified as either disadvantaged or affluent; all statistics were weighted.
SES, socioeconomic status.