title: Environmental tobacco smoke and childhood asthma: comparing exposure metrics using probability plots.
abstract: This study demonstrates the use of probability plots for assessing exposure-disease relationships in case-control studies. We reanalyze data from a study of childhood asthma and exposure to environmental tobacco smoke, comparing alternative measures of smoking intensity. Previous analyses showed a higher mean urinary cotinine-to-creatinine ratio (CCR) in cases as compared with controls and a statistically significant odds ratio with exposure defined as 30 ng/mg CCR or higher. Using probability plots, we compare alternative exposure metrics and exposure cutpoints with respect to their ability to detect a statistically significant exposure-disease effect. A strong exposure-disease response is evident, overall, and the results are fairly robust to the choice of exposure cutpoint.
authors.affiliation: Department of Environmental and Community Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway 08854.
authors.forename: D
authors.initials: D
authors.lastname: Wartenberg
authors.forename: R
authors.initials: R
authors.lastname: Ehrlich
authors.forename: D
authors.initials: D
authors.lastname: Lilienfeld
mesh_terms: D000293:Adolescent; D001741:Black or African American; D001249:Asthma / Q000208:ethnology / Q000209:etiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003367:Cotinine / Q000652:urine; D003404:Creatinine / Q000652:urine; D004781:Environmental Exposure; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D016017:Odds Ratio; D011336:Probability; D012044:Regression Analysis; D012189:Retrospective Studies; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003404:Creatinine; D003367:Cotinine