Table 4.
Relative Risk of Non-Hodgkin Lymphoma According to Lifetime Passive Smoking Exposure in Household, Workplace, and Social Settings Combined and Among Never Smokers, California Teachers Study, 1997–2007a
| Passive Smoking Characteristic | Person-Years | Non-Hodgkin Lymphoma |
Diffuse Large B-Cell Lymphoma |
Follicular Lymphoma |
Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma |
||||||||
| No. of Cases | RR | 95% CI | No. of Cases | RR | 95% CI | No. of Cases | RR | 95% CI | No. of Cases | RR | 95% CI | ||
| Total years of passive smoking | |||||||||||||
| ≤5 | 164,950 | 40 | 1.00 | Referent | 15 | 1.00 | Referent | 7 | 1.00 | Referent | 8 | 1.00 | Referent |
| 5.1–20 | 198,249 | 60 | 1.20 | 0.80, 1.79 | 14 | 0.73 | 0.35, 1.52 | 14 | 1.65 | 0.66, 4.12 | 6 | 0.56 | 0.19, 1.61 |
| 20.1–40 | 163,977 | 62 | 1.24 | 0.83, 1.86 | 15 | 0.77 | 0.37, 1.58 | 12 | 1.43 | 0.56, 3.67 | 11 | 0.98 | 0.39, 2.45 |
| >40 | 127,064 | 83 | 1.51 | 1.03, 2.22 | 14 | 0.61 | 0.29, 1.28 | 26 | 2.89 | 1.23, 6.80 | 16 | 1.18 | 0.50, 2.80 |
| P for trendb | 0.03 | 0.24 | 0.01 | 0.32 | |||||||||
| Intensity | |||||||||||||
| ≤1.0 | 236,002 | 65 | 1.00 | Referent | 21 | 1.00 | Referent | 13 | 1.00 | Referent | 8 | 1.00 | Referent |
| 1.1–2.0 | 141,256 | 58 | 1.39 | 0.97, 1.98 | 14 | 1.04 | 0.53, 2.05 | 11 | 1.37 | 0.61, 3.08 | 9 | 1.66 | 0.64, 4.32 |
| 2.1–3.0 | 109,515 | 34 | 1.09 | 0.72, 1.66 | 7 | 0.70 | 0.30, 1.65 | 13 | 2.13 | 0.98, 4.63 | 2 | 0.50 | 0.11, 2.34 |
| >3.0 | 154,918 | 77 | 1.75 | 1.25, 2.44 | 12 | 0.85 | 0.41, 1.73 | 21 | 2.42 | 1.20, 4.88 | 20 | 3.52 | 1.54, 8.06 |
| P for trendb | 0.01 | 0.54 | 0.01 | 0.01 | |||||||||
| Intensity-years | |||||||||||||
| ≤5 | 148,386 | 37 | 1.00 | Referent | 13 | 1.00 | Referent | 7 | 1.00 | Referent | 6 | 1.00 | Referent |
| 5.1–25 | 196,645 | 61 | 1.18 | 0.78, 1.77 | 13 | 0.70 | 0.32, 1.52 | 17 | 1.82 | 0.75, 4.42 | 8 | 0.87 | 0.30, 2.52 |
| 25.1–50 | 140,504 | 49 | 1.15 | 0.75, 1.78 | 11 | 0.70 | 0.31, 1.58 | 10 | 1.31 | 0.49, 3.46 | 8 | 1.04 | 0.36, 3.00 |
| >50 | 154,040 | 87 | 1.49 | 1.01, 2.20 | 17 | 0.78 | 0.37, 1.62 | 24 | 2.26 | 0.96, 5.31 | 17 | 1.51 | 0.59, 3.87 |
| P for trendb | 0.03 | 0.76 | 0.09 | 0.18 | |||||||||
Abbreviations: CI, confidence interval; RR, relative risk.
a
All models were stratified by age at cohort entry and adjusted for race (non-Hispanic white or other) and alcohol consumption 1 year before cohort entry (0 g/day, <15 g/day, ≥15 g/day, or unknown). The analyses were restricted to 58,936 never smokers who completed both questionnaires (1 and 2).
b
The first quartile of each cumulative exposure measure was used as the reference group.