| Community-level characteristics† | Total, mean (SD) | Policy,‡ mean (SD) | No policy, mean (SD) |
| Population aged 18 and older (%)** | 73.9% (4.7) | 75.6% (6.4) | 73.3% (3.8) |
| Population 25+ with college degree or higher (%)** | 25.6% (12.8) | 34.9% (14.5) | 22.7% (10.6) |
| Percentage rural** | 34.3% (33.2) | 6.1% (16.4) | 43.3% (32.1) |
| Percentage Caucasian race** | 89.4% (14.0) | 73.3% (21.8) | 92.9% (7.4) |
| Median income** | $48 546 (14 640) | $50 837 (15 407) | $47 811 (14 311) |
*p<0.05, **p<0.01; †census 2000;22 ‡policy defined by any local clean indoor air policy in the city of residence by the end of the study period.