['those', 'not', 'exposed', 'on', 'several', 'factors', 'that', 'should', 'be', 'considered', 'in', 'future', 'studies', 'that', 'seek', 'to', 'investigate', 'smoking-related', 'disease', 'risk.”', '(Cress', 'et', 'al.,', '1994,', 'pz', '40)', 'Butler', '(1994)', 'examined', 'the', 'correlates', 'of', 'household', 'smoking', 'status', 'among', '6,918', 'never', 'smoking', 'women', 'who', 'were', 'part', 'of', 'the', '1991', 'National', 'Health', 'Interview', 'Survey.', 'This', 'survey', 'was', 'designed', 'and', 'conducted', 'by', 'the', 'National', 'Center', 'for', 'Health', 'Statistics', 'to', 'generate', 'estimates', 'representative', 'of', 'the', 'U.S,', 'population.', 'Household', 'smoking', 'status', 'was', 'found', 'to', 'be', 'associated', 'with', 'fewer', 'years', 'of', 'education,', 'lower', 'family', 'income,', 'poorer', 'self-assessed', 'health,', 'higher', 'body', 'fat,', 'poorer', 'nutritional', 'habits,', 'higher', 'frequency', 'of', 'hypertension,', 'higher', 'cholesterol,', 'greater', 'prevalence', 'of', 'diabetes,', 'lower', 'use', 'of', 'preventive', 'medical', 'services,', 'higher', 'frequency', 'of', 'depression,', 'poorer', 'mental', 'health,', 'lower', 'frequency', 'of', 'physical', 'activity', 'and', 'lower', 'intensity', 'of', 'physical', 'activity.', 'These', 'research', 'results', 'indicate', 'that', 'a', 'number', 'of', 'dietary', 'and', 'lifestyle', 'factors', 'are', 'correlated', 'with', 'spousal', 'smoking', 'status.', 'Since', 'many', 'of', 'these', 'factors', 'are', 'also', 'associated', 'with', 'heart', 'disease', 'and', 'lung', 'cancer', '(see', 'Section', 'VI),', 'they', 'must', 'be', 'considered', 'as', 'potential', 'confounders', 'of', 'the', 'association', 'between', 'spousal', 'smoking', 'status', 'and', 'these', 'discasesIndeed,Sidney.et', 'al.', '(1989)', 'and', ':LeMarchand', '-et:', 'al,-.(1991)', '«each.', '‘calculated', 'sthateabouteael0%eebias', 'in', '.t', 'the', '-', '2', 'estimation', 'of', 'the:', 'association', 'between', 'lung-cancer-and.,', 'spousal', 'Smoking', ':', 'status', ',', 'could', 'be.', 'introduced', 'by', 'the', 'failure', 'to', 'control', 'for', 'a', 'single', 'factor', 'like', 'the', 'level', 'of', 'intake', 'of', 'B-carotene..', 'oa', 'This', 'amount', 'of', 'bias', 'was', 'described', 'by', 'both', 'sets', 'of', 'authors', 'as', '"modest",', 'but', 'an', 'examination', 'Of', 'the', 'potential', 'impact', 'of', 'this', 'amount', 'of', 'bias', 'when', 'the', 'observed', 'relative', 'risk', 'is', 'small', '(about', '1.1', 'or', '1.2)', 'is', 'better', 'described', 'as', '"overwhelming".', '..', 'ee10cDs2', ',', '-32-', 'ine', 'sas', ' ', ' ', '96E9', '9zZZIg']