Table I.
Subject population characteristics
| Comparison | WTCHR | ||
|---|---|---|---|
| n = 222 | n = 180 | P value | |
| Sex | .008 | ||
| Male | 89 (40.1%) | 97 (53.9%) | |
| Female | 133 (59.9%) | 83 (46.1%) | |
| Date of birth | .159 | ||
| 9/11/93–9/10/95 | 45 (20.3%) | 47 (26.1%) | |
| 9/11/95–9/10/98 | 89 (40.1%) | 77 (42.8%) | |
| 9/11/98–9/10/01 | 88 (39.6%) | 56 (31.1%) | |
| Income < $25 000* | 49 (27.4%) | 28 (19.4%) | .126 |
| Race/ethnicity† | .053 | ||
| White, % | 89 (40.1%) | 66 (36.9%) | |
| Black, % | 19 (8.6%) | 16 (8.9%) | |
| Asian, % | 44 (19.8%) | 49 (27.4%) | |
| Other, % | 10 (4.5%) | 16 (8.9%) | |
| Hispanic | 60 (27.0%) | 32 (17.9%) | |
| Exposures‡ | |||
| Dust cloud exposure (%) | 1 (0.5) | 61 (38.6) | <.0001 |
| Home dust exposure (%) | 17 (7.7) | 98 (56) | <.0001 |
| Traumatic exposure (%) | 95 (42.8) | 150 (83.3) | <.0001 |
| BMI category | .045 | ||
| Normal | 162 (73.0%) | 150 (83.3%) | |
| Overweight | 36 (16.2%) | 19 (10.6%) | |
| Obese | 24 (10.8%) | 11 (6.1%) | |
| Tobacco smoke exposure§ | |||
| Cotinine, ng/mL (IQR) | 0.324 (0.106, 0.69) | 0.412 (0.106, 0.984) | .294 |
| Low | 102 (45.9%) | 73 (40.6%) | |
| Medium | 95 (42.8%) | 79 (43.9%) | .353 |
| High | 25 (11.3%) | 28 (15.6%) | |
| Asthma before September 11, 2001 | 15 (6.9%) | 11 (6.3%) | .842 |
All bold values indicate P < 0.05.
*
n = 43 missing for comparison group; n = 27 missing for WTCHR group.
†
n = 1 missing for WTCHR.
‡
n = 18 missing for dust cloud exposure; n = 2 missing for home dust exposure.
§
Evaluated by saliva cotinine concentration and questionnaire. For subjects without saliva cotinine concentration, we categorized no smoker and no secondhand smoke exposure into low, no smoker but secondhand smoke exposure into medium, and smoker into high category.