Tobacco Documents Online

Janerich, D.T., Thompson, W.D., Varela, L.R., Greenwald, P., Chorost, S., Tucci, C., Zaman, M.B., Melamed, M.R., Kiely, M., and McKneally, M.F., "Lung Cancer and Exposure to Tobacco Smoke in the Household," The New England Journal of Medicine 323: 632-636, 1990. This study included 191 case-control pairs. The authors matched cases and controls on the basis of whether the interview was conducted directly or with a surrogate respondent; 129 pairs were direct interviews and 62 pairs were interviews with surrogates. Nonsmokers were defined as never having smoked more than 100 cigarettes. Interviews were conducted face-to-face, and all but five of the cases were histologically confirmed. Questions were asked during the interview concerning smoking in the household for each residence in which the subject had lived. The authors calculated smoker-years of exposure based on the number of years the subject lived in-each residence multiplied by the number of smokers in that residence. Of the 28 risk estimates presented in the paper, a statistically significant OR was reported for the exposure index of 25 or more smoker-years in childhood and adolescence. This was the only statistically significant risk estimate reported in the study, and was used by the authors to suggest that "approximately 17 percent of lung cancers among nonsmokers can be attributed to high levels of exposure to cigarette smoke during childhood and adolescence." Using the 129 case-control pairs interviewed directly, the authors calculated an OR of 0.93 (95% CI 0.55-1.57) for ever having had a spouse who smoked. This risk estimate was not statistically significant. • The authors wrote that "(w]e found no adverse effects of exposure to- tobacco smoke in the workplace." The only odds ratio for workplace exposure presented was for 150 person-years of exposure. This OR was not statistically significant (OR = 0.91, 95% CI 0.80-1.04). The authors stated that the OR indicated "'no evidence of an adverse effect of environmental tobacco smoke in the workplace." Data on exposure in social settings was also collected. The authors reported a "statistically significant inverse association between environmental tobacco smoke and lung cancer" for the analyses of social exposures. When exposure during childhood and adolescence (defined as up to age 21) was analyzed, the authors calculated an OR of 2.59 (95% CI, 1.22-5.49) for 25 or more smoker- years of exposure, based on 113 case-control pairs. Similarly, when the analysis was conducted using all 191 case-control pairs, the OR was 2.07 (95% CI 1.16- 3.68) ..