[' ', ' ', ' ', 'PASSIVE', 'SMOKING', 'IN', 'CHILDHOOD', 'yr', 'of', 'age', 'and', 'members', 'of', 'their', 'households', 'constituted', 'the', 'study', 'population.', 'Questionnaire', 'Personal,', 'demographic,', 'and', 'medical', 'infor-', 'mation', 'were', 'ascertained', 'using', 'a', 'standard', 'questionnaire.', 'Parents', 'responded', 'for', 'children', '15', 'yr', 'of', 'age', 'or', 'younger.', 'Several', 'respiratory', 'symptoms', 'and', 'illnesses', 'were', 'selected', 'for', 'evaluation:', 'these', 'included', 'cough,', 'phlegm,', 'wheeze,', 'asthma,', 'bronchitis,', 'and', 'colds', 'settling', 'in', 'the', 'chest.', 'In', 'general,', 'questions', 'involved', 'a', 'past', 'history', 'of', 'these', 'conditions,', 'rather', 'than', 'ascertainment', 'of', 'symptoms', 'and', 'illnesses', 'de-', 'fined', 'only', 'at', 'the', 'time', 'of', 'interview.', 'Specific', 'questions', 'used', 'to', 'define', 'these', 'respiratory', 'con-', 'ditions', 'and', 'results', 'concerning', 'neonatal,', 'al-', 'lergic,', 'and', 'other', 'conditions', 'are', 'reported', 'else-', 'where', '(43).', 'The', 'diagnostic', 'criteria', 'for', 'asthma,', 'reported', 'by', 'Higgins', 'and', 'Keller', '(44)', 'and', 'Broder', 'and', 'coworkers', '(45),', 'were', 'used,', 'and', 'a', 'probable', 'or', 'suspect', 'diagnosis', 'was', 'included', 'as', 'asthma.', 'Information', 'was', 'available', 'concerning', 'pa-', 'rental', 'education,', 'family', 'size,', 'and', 'presence', 'or', 'absence', 'of', 'parental', 'respiratory', 'symptoms', 'or', 'illness.', 'Categories', 'of', 'parental', 'education', 'in-', 'cluded:', '(2)', 'at', 'least', 'one', 'parent', 'who', 'did', 'not', 'complete', 'high', 'school,', '(2)', 'both', 'parents', 'com-', 'pleted', 'high', 'school,', 'and', '(3)', 'either', 'parent', 'at-', 'tended', 'college.', 'Family', 'size', 'was', 'defined', 'as', 'the', 'number', 'of', 'persons', 'residing', 'in', 'a', 'household.', 'Categorical', 'definitions', 'were', 'used', 'to', 'classify', 'children', 'according', 'to', 'whether', 'their', 'mothers', 'or', 'fathers', 'had', 'a', 'history', 'or', 'diagnosis', 'of', 'the', 'specific', 'respiratory', 'condition', 'under', 'study.', 'Pulmonary', 'Function', 'A', 'Wedge®', 'spirometer', '(Med-Science', 'Elec-', 'tronics,', 'Burlington,', 'MA)', 'and', 'a', 'two-channel', 'recorder', '(Sanborn', 'Co.,', 'Waltham,', 'MA)', 'oper-', 'ating', 'at', 'a', 'paper', 'speed', 'of', '25', 'mm/s', 'were', 'used', 'to', 'measure', 'lung', 'function.', 'Following', 'maxi-', 'mal', 'inspiration,', 'subjects', 'performed', 'several', 'maximal', 'expiratory', 'efforts', 'until', '2', 'satisfac-', 'tory', 'tracings', 'were', 'obtained.', 'Measurements', 'of', 'volume', 'and', 'flow', 'were', 'based', 'on', 'the', 'trac-', 'ing', 'with', 'the', 'largest', 'vital', 'capacity', 'and', 'were', 'adjusted', 'to', 'body', 'temperature', 'and', 'pressure', 'saturated', 'with', 'water', 'vapor', '(TPs).', 'Seven', 'volume', 'and', 'flow', 'measurements', 'were', 'available', '(46);', 'forced', 'expiratory', 'volume', 'in', 'one', 'second', '(FEV,),', 'forced', 'vital', 'capacity', '(FVC),', 'and', 'forced', 'expiratory', 'flow', 'at', '50%', 'of', 'vital', '“apacity', '(Vmaxso)', 'were', 'selected', 'for', 'use', 'in', 'this', 'study', 'because', 'they', 'have', 'been', 'used', 'in', 'other', 'studies', 'and', 'were', 'available', 'at', 'subsequent', 'ex-', 'aminations.', 'Lung', 'function', 'analyses', 'reported', 'here', 'involved', 'young', 'persons', '10', 'to', '19', 'yr', 'of', 'xe', 'in', '1962', 'through', '1965.', '___.', 'Measures', 'of', 'Passive', 'Smoking', 'ame', 'were', 'classified', 'by', 'smoking', 'habits', 'mtn', 'household', 'members', 'at', 'the', 'time', 'of', 'wa', 'eas', 'Only', 'cigarette', 'smoking', 'and', 'not', 'pipe', '‘mee', 'r', 'Smoking', 'was', 'taken', 'into', 'account.', 'Five', '“ures', 'of', 'passive', 'smoking', 'were', 'developed.', 'Le', ':', 'fig', 'and', 'Past', 'Parental', 'Smoking', '967', 'TABLE', '1', 'REGRESSION', 'STATISTICS', 'FOR', 'LUNG', 'FUNCTION', 'MEASUREMENTS,', 'ASYMPTOMATIC', 'NONSMOKING', 'MALES', 'AND', 'FEMALES,', 'TECUMSEH,', '1962-1965"', ' ', 'Regression', 'Statistics', ' ', ' ', 'Age', 'Sex', '7)', 'Measure', '0', 'a', 'b,', 'o,', 'R', 'Sy-x', 'Male', '10-15', 'FEV,', '526', '-5.293', 'Onis', '0043', '0.747', '0423', 'FvG', '528', '-6447', 'oe', '0.052', '0739', '0507', 'Vmax,', '516', '4511', '0.152', '0.038', '0.490', 'area', '16-19', 'FEV,', '127', '~722', '-', '0046', '0.289', '0534', 'Fvc', '127', '~6.214', '-', '0064', '0303', '720', 'Vary,', '124', '1.226', 'ren', '0.034', '0075', '0.890', 'Female', '10-15', 'FEV,', '524', '3688', '6.093', '0032', '0560', '0396', 'Fvc', '$24', '~4.322', '0.096', '0.038', '0559', '437', 'Vinakiy', 'S14', '2816', 'at', '0031', '0264', 'O7S4', '16-19', 'FEV,', '165', '-3397', '-', '0.040', '0233', '0432', 'Fvc', '155', '3.305', '-', '0041', '0.220', '0.459', 'Vinaxes', '154', '-2.134', '=', '00s?', '0054', '0949', ' ', '*', 'Regression', 'model:', 'Predicted', 'lung', 'function', '=', '@', '+b,', '-', 'age', 'yt)', '+', 'b;', '(height', 'in', 'cm}', 'for', '10-', 'to', '15-77-0lda;', 'predicted', 'ung', 'function', '=', 'a', '+b,', '-', 'height', '(em)', 'for', '16-', 'to', '19-yr-clds.', 'Father:', 'Never', 'Current', 'Current', 'Never', '=', 'All', 'Mother:', 'Never', 'Current', 'Never', 'Current', 'Ouhers', 'Ti,', 'Number', 'of', 'Parental', 'Smokers', 'During', "Child's", 'Lifetime:', '(0,', '1,', 'and', '2).', 'IH,', 'Number', 'of', 'Current', 'Household', 'Smokers:', '(0,', '1,', '2,', '3,', 'or', 'more).', 'TV.', 'Duration', 'of', 'Parental', 'Smoking', 'During', 'Child’s', 'Lifetime.', 'V.', 'Current', 'Amount', 'of', 'Parental', 'Smoking.', 'The', 'first', 'index', 'provided', 'one', 'of', 'the', 'more', 'extreme', 'contrasts', 'in', 'passive', 'smoke', 'exposure,', 'where', 'children', 'having', 'both', 'parents', 'who', 'never', 'smoked', 'are', 'compared', 'with', 'those', 'having', 'both', 'Parents', 'who', 'were', 'current', 'smokers.', 'Children', 'from', 'households', 'where', 'only', 'fathers', 'smoked', 'and', 'where', 'only', 'mothers', 'smoked', 'could', 'also', 'be', 'compared', 'using', 'this', 'index.', 'The', '“all', 'others”', 'category', 'included', 'children', 'having', 'one', 'or', 'both', 'parents', 'who', 'were', 'former', 'smokers.', 'For', 'the', 'second', 'index,', 'children', 'were', 'categorized', 'by', 'presence', 'or', 'absence', 'of', 'parental', 'smoking', 'dur-', 'ing', 'the', 'child’s', 'lifetime.', 'To', 'include', 'potential', 'prenatal', 'exposure', 'to', 'parental', 'smoking,', 'a', 'child’s', 'lifetime', 'was', 'defined', 'as', '1', 'yr', 'before', 'birth', 'to', 'the', 'time', 'of', 'examination', 'in', '1962-1965.', 'Smoking', 'habits', 'of', 'siblings', 'and', 'relatives', 'who', 'were', '16', 'yr', 'of', 'age', 'or', 'older', 'were', 'included', 'with', 'those', 'of', 'parents', 'in', 'the', 'classification', 'of', 'cur-', 'rent', 'household', 'smokers.', 'For', 'duration', 'and', 'amount', 'of', 'parental', 'smoking,', 'the', 'number', 'of', 'years', 'and', 'average', 'number', 'of', 'cigarettes', 'smoked', 'per', 'day', 'by', 'each', 'parent', 'were', 'summed.', 'Data', 'Analysis', 'Prevalence', 'rates', 'of', 'respiratory', 'symptoms', 'and', 'illnesses,', 'and', 'levels', 'of', 'lung', 'function', 'in', 'chil-', 'dren', 'and', 'adolescents', 'were', 'compared', 'across', 'parental', 'smoking', 'categories', 'using', '5-yr,', 'age-', 'and', 'sex-specific', 'groups.', 'Stratification', 'was', 'used', 'initially', 'to', 'control', 'for', 'potential', 'con-', 'founding', 'by', 'parental', 'education,', 'family', 'size,', 'parental', 'history', 'of', 'respiratory', 'symptoms', 'or', 'illness,', 'and', 'active', 'smoking', 'by', 'adolescents.', 'Significance', 'was', 'assessed', 'using', 'standard', '¢', 'and', 'chi-square', 'tests', 'for', 'differences', 'between', 'means', 'and', 'proportions,', 'respectively.', 'Age-adjusted', 'prevalence', 'rates', 'were', 'derived', 'using', 'the', 'age', ' ', 'distribution', 'of', 'all', 'nonsmoking', 'subjects', '0', 'to', '19', 'yr', 'of', 'age', 'examined', 'in', '1962-1965', 'as', 'a', 'stan-', 'dard,', 'A', 'Cochran/Mantel-Haenszel', 'procedure', 'was', 'used', 'to', 'test', 'for', 'the', 'average', 'partial', 'as-', 'sociation', 'between', 'passive', 'smoking', 'and', 'a', 'spe-', 'cific', 'respiratory', 'symptom', 'or', 'illness,', 'control-', 'ling', 'for', 'the', 'effects', 'of', 'age', 'group', 'and', 'assess-', 'ing', 'whether', 'a', 'linear', 'trend', 'exists', '(47).', 'To', 'compare', 'age-adjusted', 'means,', 'variances', 'for', 'those', 'having', 'or', 'not', 'having', 'a', 'specific', 'respira-', 'tory', 'condition', 'were', 'calculated,', 'and', 'a', 'stan-', 'dard', 'z', 'statistic', 'for', 'comparing', 'means', 'with', 'known', 'but', 'unequal', 'variances', 'was', 'used', 'to', 'de-', 'termine', 'significance,', 'Multiple', 'logistic', 'regression', '(48)', 'was', 'em-', 'ployed', 'to', 'control', 'for', 'potential', 'confounders', 'simultaneously.', 'Sex-specific', 'analyses', 'were', 'performed', 'using', 'each', 'respiratory', 'condition', 'as', 'the', 'response', 'variable.', 'The', 'number', 'of', 'pa-', 'rental', 'smokers', 'during', 'a', 'child’s', 'lifetime', '(0,', '1,', '2)', 'was', 'selected', 'as', 'the', 'independent', 'variable', 'of', 'primary', 'interest', 'and', 'was', 'coded', 'using', '2', 'in-', 'dicator', 'variables.', 'Parental', 'education,', 'family', 'size,', 'parental', 'symptom', 'or', 'illness,', 'as', 'well', 'as', 'age', 'of', 'the', 'child', 'were', 'considered', 'as', 'covari-', 'ates.', 'For', 'asthma', 'a', 'diagnosis', 'of', 'hay', 'fever', 'and', 'history', 'of', 'other', 'allergies', 'were', 'also', 'included', 'in', 'the', 'model', 'as', 'potential', 'predictors.', 'Several', 'methods', 'of', 'including', 'age', 'were', 'considered;', 'tegression', 'coefficients', 'were', 'similar', 'for', 'each.', 'Likelihood', 'ratio', 'tests', '(48)', 'were', 'used', 'to', 'com-', 'pare', 'methods', 'of', 'including', 'age,', 'to', 'decide', 'whether', 'certain', 'variables', 'should', 'be', 'retained', 'in', 'the', 'logistic', 'model,', 'and', 'to', 'confirm', 'whether', 'or', 'not', 'statistical', 'interaction', 'was', 'present.', 'Goodness', 'of', 'fit', 'for', 'these', 'logistic', 'models', 'was', 'assessed', 'using', 'methods', 'proposed', 'by', 'Leme-', 'show', 'and', 'Hosmer', '(49),', 'where', 'information', 'from', 'both', 'cases', 'and', 'noncases', 'is', 'incorporated.', 'Levels', 'of', 'lung', 'function', 'were', 'expressed', 'as', 'a', 'percent', 'of', 'predicted', 'or', 'were', 'adjusted', 'using', 'analysis', 'of', 'covariance.', 'Predicted', 'values', 'of', 'FEV,,', 'FVC,', 'and', 'Vmaxs,', 'were', 'obtained', 'by', 'regressing', 'observed', 'values', 'of', 'asymptomatic', 'nonsmokers', 'on', 'age', 'and', 'height', 'separately', 'for', '2', 'age', 'and', 'sex', 'groups', 'using', 'the', 'population', 'of', 'nonsmokers', '10', 'to', '19', 'yr', 'of', 'age', 'who', 'were', ' ', 'EPEO', 'O9LTS', ' ', ' ']