Table 2.
Relationship of smoking-related covariates and prior respiratory disease with lung cancer risk in a Texas Case–Control Study of Mexican Americans, 1991–2010
| Variable | No. of cases | (%) | No. of controls | (%) | Multivariate odds ratioa | 95 % confidence interval |
|---|---|---|---|---|---|---|
| Smoking status | ||||||
| Never | 43 | 21.1 | 110 | 33.9 | ||
| Former | 72 | 35.3 | 118 | 36.3 | 1.6 | 1.0, 2.6 |
| Current | 89 | 43.6 | 97 | 29.9 | 2.4 | 1.5, 4.0 |
| Current smokers | ||||||
| Smoking duration | ||||||
| ≤30 years | 15 | 16.9 | 30 | 32.6 | ||
| >30 years | 74 | 83.1 | 62 | 67.4 | 1.9 | 0.8, 4.5 |
| No. of cigarettes/day | ||||||
| ≤20 per day | 58 | 65.2 | 81 | 87.1 | ||
| >20 per day | 31 | 34.8 | 12 | 12.9 | 3.7 | 1.7, 8.1 |
| Smoking intensity | ||||||
| Light smoker: 0<pack-years ≤ 20 | 13 | 14.6 | 47 | 51.1 | ||
| Moderate smoker: 20<pack-years ≤ 40 | 24 | 27.0 | 23 | 25.0 | 4.2 | 1.7, 10.3 |
| Heavy smoker: 40<pack-years | 52 | 58.4 | 22 | 23.9 | 10.0 | 4.0, 24.7 |
| Former smokers | ||||||
| Smoking duration | ||||||
| ≤30 years | 25 | 34.7 | 70 | 62.0 | ||
| >30 years | 47 | 65.3 | 43 | 38.0 | 1.8 | 0.9, 3.7 |
| No. of cigarettes/day | ||||||
| ≤20 per day | 43 | 59.7 | 93 | 82.3 | ||
| >20 per day | 29 | 40.3 | 20 | 17.7 | 3.3 | 1.5, 7.1 |
| Smoking intensity | ||||||
| Light smoker: 0<pack-years ≤ 20 | 21 | 29.2 | 76 | 67.3 | ||
| Moderate smoker: 20<pack-years ≤ 40 | 21 | 41.7 | 21 | 18.6 | 3.6 | 1.6, 8.33 |
| Heavy smoker: 40<pack-years | 30 | 29.2 | 16 | 14.2 | 5.8 | 2.4, 13.9 |
| Years since smoking cessation | ||||||
| ≤10 years | 42 | 58.3 | 49 | 41.5 | ||
| >10 years | 30 | 41.7 | 69 | 58.5 | 0.4 | 0.2, 0.7 |
| Age at smoking cessation | ||||||
| ≤30 years | 2 | 2.8 | 25 | 21.2 | ||
| >30 years | 70 | 97.2 | 93 | 78.8 | 5.8 | 1.2, 27.4 |
| Smoking cessation | ||||||
| Years>10, Age ≤30 | 2 | 2.8 | 22 | 18.6 | ||
| Years<10, Age ≤30 | 0 | 0.0 | 3 | 2.5 | – | – |
| Years>10, Age>30 | 28 | 38.9 | 47 | 39.8 | 3.7 | 0.7, 18.8 |
| Years<10, Age>30 | 42 | 58.3 | 46 | 39.0 | 8.2 | 1.6, 40.6 |
| Respiratory co-morbidities | ||||||
| No respiratory disease | 115 | 57.2 | 224 | 68.9 | ||
| Any respiratory disease | 86 | 42.8 | 101 | 31.1 | 1.5 | 1.0, 2.3 |
| No Asthma | 184 | 92.5 | 305 | 93.8 | ||
| Asthma | 15 | 7.5 | 20 | 6.2 | 1.3 | 0.6, 2.8 |
| No COPD | 154 | 77.0 | 285 | 88.0 | ||
| COPD | 46 | 23.0 | 39 | 12.0 | 2.0 | 1.2, 3.3 |
| No hay fever | 184 | 94.4 | 284 | 87.7 | ||
| Hay fever | 11 | 5.6 | 40 | 12.3 | 0.4 | 0.2 0.9 |
| No pneumonia | 148 | 75.1 | 286 | 88.0 | ||
| Pneumonia | 49 | 24.9 | 39 | 12.0 | 2.2 | 1.3, 3.6 |
a
All variables are adjusted for age, sex, and self-reported pesticide exposure. Respiratory co-morbidities are also adjusted for smoking intensity (number of smoking years/number of cigarettes per day)