Participant characteristics
| Characteristic | |
| Age of child (years) | |
| 25th–50th–75th percentiles | 0.8–2.1–9.9 |
| Race of child, n (%) | |
| Black, non-Hispanic | 18 (75.0) |
| White, non-Hispanic | 5 (20.8) |
| Other, non-Hispanic | 1 (4.2) |
| Sex of child, n (%) | |
| Male | 13 (52.0) |
| Insurance type, n (%) | |
| Public/self-pay | 22 (88.0) |
| Private | 3 (12.0) |
| Income level, n (%) | |
| <US$14 999 | 16 (66.7) |
| Number of smokers, n (%) | |
| 1 smoker | 18 (72.0) |
| Number of cigarettes/day, n (%) | |
| <10 | 15 (60.0) |
| Daily electronic cigarette use, n (%) | |
| Yes | 1 (4.0) |
| Housing, n (%) | |
| Single-family | 13 (52.0) |
| Multiunit or apartment | 12 (48.0) |
| Cleaning frequency, n (%) | |
| Daily | 19 (76.0) |
| Chief complaints, n (%) | |
| Cough or difficulty breathing | 12 (48.0) |
| Past medical history, n (%) | |
| Asthma | 8 (32.0) |
| Asthma or bronchiolitis | 10 (40.0) |
| Discharge diagnosis, n (%) | |
| Asthma or bronchiolitis | 8 (32.0) |
| Past medical history or discharge diagnosis, n (%) | |
| Asthma or bronchiolitis | 13 (52.0) |