title: A comparison of creatinine vs. specific gravity to correct for urinary dilution of cotinine.
abstract: BACKGROUND
  The validity of urinary correction standards has not been established for most analytes.
  
  
  METHODS
  We compared urinary creatinine and specific gravity as dilution correction standards for cotinine in a community-based study of smokers.
  
  
  RESULTS
  Models of blood cotinine regressed against CR or SG (measured by total soluble solids) significantly improved the fit compared to a model without a dilution measure (P < 0.01). There were no differences in model fit between CR- and SG-corrected values. Both CR and SG were significant predictors of urinary cotinine regressed against cigarettes smoked per day (P < 0.01).
  
  
  CONCLUSIONS
  CR and SG are valid and interchangeable correction standards.
authors.affiliation: Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA. jmuscat@psu.edu
authors.forename: Joshua E
authors.initials: JE
authors.lastname: Muscat
authors.forename: Anderson
authors.initials: A
authors.lastname: Liu
authors.forename: John P
authors.initials: JP
authors.lastname: Richie
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000652:urine; D003367:Cotinine / Q000652:urine*; D003404:Creatinine / Q000652:urine*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012907:Smoking / Q000652:urine; D013046:Specific Gravity; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003404:Creatinine; D003367:Cotinine