Table 1.
Demographic characteristics and hospitalizations of the studied population [n (%)].
| Hospitalizations | ||||||||
|---|---|---|---|---|---|---|---|---|
| Characteristic | Person-yearsa | Asthma | ARI | COPD | ||||
| Total population | 164,289,936 (100.0) | 911,444 (100.0) | 331,469 (100.0) | 1,948,903 (100.0) | ||||
| Exposure | ||||||||
| Clean | 65,271,804 (39.7) | 320,693 (35.2) | 118,239 (35.7) | 692,247 (35.5) | ||||
| Fuel only | 4,529,951 (2.8) | 24,765 (2.7) | 8,466 (2.6) | 55,126 (2.8) | ||||
| Waste only | 69,479,535 (42.3) | 403,334 (44.3) | 144,613 (43.6) | 848,798 (43.6) | ||||
| Fuel and waste | 25,008,646 (15.2) | 162,652 (17.8) | 60,151 (18.1) | 352,732 (18.1) | ||||
| Sex | ||||||||
| Female | 84,417,102 (51.4) | 600,327 (65.9) | 179,061 (54.0) | 995,977 (51.1) | ||||
| Male | 79,872,834 (48.6) | 311,117 (34.1) | 152,408 (46.0) | 952,926 (48.9) | ||||
| Race | ||||||||
| African American | 14,339,797 (8.7) | 162,482 (17.8) | 45,357 (13.7) | 100,906 (5.2) | ||||
| Caucasian | 149,950,139 (91.3) | 748,962 (82.2) | 286,112 (86.3) | 1,847,997 (94.8) | ||||
| Age group (years) | ||||||||
| 0 | 2,057,008 (1.3) | 13,340 (1.5) | 55,502 (16.7) | 446 (0.0) | ||||
| 1–2 | 4,263,638 (2.6) | 31,052 (3.4) | 26,302 (7.9) | 520 (0.0) | ||||
| 3–5 | 6,456,134 (3.9) | 25,724 (2.8) | 10,505 (3.2) | 392 (0.0) | ||||
| 6–9 | 8,747,610 (5.3) | 20,657 (2.3) | 5,989 (1.8) | 349 (0.0) | ||||
| 10–24 | 33,073,852 (20.1) | 96,648 (10.6) | 24,247 (7.3) | 4,447 (0.2) | ||||
| 25–49 | 58,830,783 (35.8) | 297,430 (32.6) | 62,607 (18.9) | 98,675 (5.1) | ||||
| 50–74 | 39,683,599 (24.2) | 290,371 (31.9) | 74,766 (22.6) | 928,603 (47.6) | ||||
| ≥ 75 | 11,177,312 (6.8) | 136,222 (14.9) | 71,551 (21.6) | 915,471 (47.0) | ||||
| aPerson-years determined by the numbers of residents in the study ZIP codes during each year (1993–2008) according to characteristic. | ||||||||