Table 1.
Descriptive statistics for the study population.
| Dementia cohort | AD cohort | |||
|---|---|---|---|---|
| Variables | Number | % | Number | % |
| Number of events | 2,025,130 | 16.6 | 804,668 | 6.5 |
| Number of the total population | 12,233,371 | 100 | 12,456,447 | 100 |
| Total person-years | 89,035,081 | 100 | 93,278,266 | 100 |
| Median follow-up years | 7 | 7 | ||
| Age at entry (years) | ||||
| 65–74 | 9,597,788 | 78.5 | 9,734,481 | 78.1 |
| 75–114 | 2,635,583 | 21.5 | 2,721,966 | 21.9 |
| Sex | ||||
| Male | 5,023,879 | 41.1 | 5,107,942 | 41.0 |
| Female | 7,209,492 | 58.9 | 7,348,505 | 59.0 |
| Race | ||||
| White | 11,023,202 | 90.1 | 11,214,287 | 90.0 |
| Black | 649,081 | 5.3 | 666,619 | 5.4 |
| Othera | 561,088 | 4.6 | 575,541 | 4.6 |
| Medicaid eligibility | ||||
| Dual-eligible | 800,139 | 6.5 | 852,499 | 6.8 |
| Non-dual eligible | 11,433,232 | 93.5 | 11,603,948 | 93.2 |
| Comorbidity | ||||
| Diabetes | 4,433,314 | 36.2 | 4,590,000 | 36.8 |
| Hypertension | 10,273,506 | 84.0 | 10,502,180 | 84.3 |
| Stroke | 1,991,730 | 16.3 | 2,137,239 | 17.2 |
| Heart failure | 3,388,540 | 27.7 | 3,598,028 | 28.9 |
| No comorbiditiesb | 1,642,674 | 13.4 | 1,865,751 | 15.0 |
| Air pollutantsc | ||||
| Annual PM2.5 (µg/m3) | 9.3 (3.2) | 9.3 (3.2) | ||
| Annual NO2 (ppb) | 17.1 (11.6) | 17.1 (11.6) | ||
| Warm-season O3 (ppb) | 42.6 (5.3) | 42.6 (5.3) | ||
aOther included Asian, Hispanic, American Indian, or Alaskan Native, and unknown.
bMeans none of the above comorbidities.
cPresented as mean concentration (interquartile range).