Table 1.
Baseline characteristics of older (aged≥65) patients initiating dialysis by PM2.5 levels (N=384,276).
| Factor | PM2.5≤12μg/m3 | PM2.5>12μg/m3 | |
|---|---|---|---|
| N | 335,391 | 48,885 | |
| Individual level characteristics | |||
| Age at dialysis initiation (years) | 74 (69, 80) | 75 (69, 81) | |
| Female | 148,233 (44.2%) | 22,369 (45.8%) | |
| Race/ethnicity | White | 218,650 (65.2%) | 24,170 (49.4%) |
| Black | 68,831 (20.5%) | 10,048 (20.6%) | |
| Hispanic | 32,161 (9.6%) | 9,606 (19.7%) | |
| Other | 15,749 (4.7%) | 5,061 (10.4%) | |
| BMIa (kg/m2) | 27.4 (23.5, 32.3) | 26.6 (23.1, 31.5) | |
| Primary cause of kidney failure | Diabetes | 148,217 (44.2%) | 23,503 (48.1%) |
| Hypertension | 117,073 (34.9%) | 16,882 (34.5%) | |
| Glomerulonephritis | 16,817 (5.0%) | 1,903 (3.9%) | |
| Other | 53,284 (15.9%) | 6,597 (13.5%) | |
| Current smoker | 13,565 (4.0%) | 1,399 (2.9%) | |
| Nephrology care at dialysis initiation | No care | 74,798 (22.3%) | 10,921 (22.3%) |
| Unknown care | 43,655 (13.0%) | 10,589 (21.7%) | |
| <6 months of care | 44,806 (13.4%) | 7,949 (16.3%) | |
| 6–12 months | 63,555 (19.0%) | 8,204 (16.8%) | |
| >12 months | 108,566 (32.4%) | 11,221 (23.0%) | |
| ZIP code-level characteristics | |||
| Percent Black | 6.2 (1.7, 21.1) | 5.2 (2.0, 17.6) | |
| Percent Hispanic | 6.9 (2.7, 18.4) | 19.0 (4.6, 50.0) | |
| Population density | 393 (71, 1,275) | 1,974 (873, 3,761) | |
| Mean education year | 13.2 (12.6, 14.0) | 13.0 (12.2, 13.8) | |
| Median income | 48,520 (38,583, 63,677) | 50,083 (39,222, 64,211) | |
| Monthly housing cost | 928 (721,1245) | 1,145 (871, 1437) | |
| Percent below 200% FPL | 36.0 (24.5, 47.3) | 39.9 (27.2, 52.1) | |
| Urbanicity | Urban | 243,681 (72.7%) | 45,017 (92.1%) |
| Urban cluster | 62,219 (18.6%) | 2,989 (6.1%) | |
| Rural | 29,491 (8.8%) | 879 (1.8%) |
Continuous variables were presented as [median (IQR)], categorical variables were presented as [frequency (%)]
a
BMI: Body Mass Index; FPL: Federal poverty line