Table 1.
Results of studies on exposure to secondhand smoke and risk of lung cancer among never smokers
| Study | Design/population | Exposure Group | Reference Group | Risk Estimate (95% CI) | Adjustment Variables | |
|---|---|---|---|---|---|---|
| Hackshaw et al. (1997) (98) | Meta-analysis: 39 studies (5 cohort, 34 case- control) of “lifelong non-smokers” 5005 total lung cancer cases Study locations: USA, Europe, Asia Publication dates: 1981–1997 |
Spousal Exposure: | Age only, when possible | |||
| Women (37 studies, 4626 cases): | ||||||
| Husband currently smoked | vs. | Husband never smoked | 1.24 (1.13–1.36) | |||
| Men (9 studies, 274 cases): | ||||||
| Wife currently smoked | vs. | Wife never smoked | 1.34 (0.97–1.84) | |||
| Men and Women (39 studies, 5005 cases): | ||||||
| Spouse currently smoked | vs. | Spouse never smoked | 1.23 (1.13–1.34) | |||
|
| ||||||
| Zhong et al. (2000) (41) | Meta-analysis: 40 studies (5 cohort, 35 case- control) of “lifetime non smoking” subjects 5140 total lung cancer cases Study locations: USA, Europe, Asia Publication dates: 1981–1999 |
Spousal Exposure: | Age and demographic characteristics, when possible | |||
| Women (40 studies, No. cases not stated): | ||||||
| Husband ever smoked | vs. | Husband never smoked | 1.20 (1.12–1.29) | |||
| Men (11 studies, 443 cases): | ||||||
| Wife ever smoked | vs. | Wife never smoked | 1.48 (1.13–1.92) | |||
| Workplace Exposure: | ||||||
| Women (14 studies, 2594 cases): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.15 (1.04–1.28) | |||
| Men (5 studies, 254 cases): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.29 (0.93–1.78) | |||
| Men and Women (19 studies, 2848 cases): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.16 (1.05–1.28) | |||
| Childhood Exposure: | ||||||
| Women (18 studies, 3584 cases): | ||||||
| Ever exposed to SHS during childhood | vs. | Never exposed to SHS during childhood | 0.91 (0.83–1.00) | |||
|
| ||||||
| Surgeon General Report (2006) (81) | Meta-analysis: 52 studies (8 cohort, 44 case- control) of “lifetime nonsmokers” Total number of cases not stated Study locations: North America, Europe, Asia Publication dates: 1981–2002 |
Spousal Exposure: | not stated | |||
| Women (No. studies and cases not stated): | ||||||
| Smoking husband | vs. | Nonsmoking husband | 1.22 (1.10–1.35) | |||
| Men (No. studies and cases not stated): | ||||||
| Smoking wife | vs. | Nonsmoking wife | 1.37 (1.05–1.79) | |||
| Workplace Exposure: | ||||||
| Women (25 studies, No. cases not stated): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.22 (1.10–1.35) | |||
| Men (11 studies, No. cases not stated): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.12 (0.86–1.50) | |||
| Men and Women (25 studies, No. cases not stated): | ||||||
| Workplace SHS exposure | vs. | No workplace SHS exposure | 1.22 (1.13–1.33) | |||
| Childhood Exposure: | ||||||
| Women (No. studies and cases not stated): | ||||||
| Mother smoked during childhood | vs. | Mother did not smoke during childhood | 1.28 (0.93–1.78) | |||
| Father smoked during childhood | vs. | Father did not smoke during childhood | 1.17 (0.91–1.50) | |||
| Men and Women (No. studies and cases not stated): | ||||||
| Mother smoked during childhood | vs. | Mother did not smoke during childhood | 1.15 (0.86–1.52) | |||
| Father smoked during childhood | vs. | Father did not smoke during childhood | 1.10 (0.89–1.36) | |||
| Either parent smoked during childhood | vs. | Neither parent smoked during childhood | 1.11 (0.94–1.31) | |||
Abbreviations:
CI: confidence interval
No.: number of
SHS: secondhand smoke