title: Use of a urinary sugars biomarker to assess measurement error in self-reported sugars intake in the nutrition and physical activity assessment study (NPAAS).
abstract: BACKGROUND
  Measurement error in self-reported sugars intake may be obscuring the association between sugars and cancer risk in nutritional epidemiologic studies.
  
  
  METHODS
  We used 24-hour urinary sucrose and fructose as a predictive biomarker for total sugars, to assess measurement error in self-reported sugars intake. The Nutrition and Physical Activity Assessment Study (NPAAS) is a biomarker study within the Women's Health Initiative (WHI) Observational Study that includes 450 postmenopausal women ages 60 to 91 years. Food Frequency Questionnaires (FFQ), four-day food records (4DFR), and three 24-hour dietary recalls (24HRs) were collected along with sugars and energy dietary biomarkers.
  
  
  RESULTS
  Using the biomarker, we found self-reported sugars to be substantially and roughly equally misreported across the FFQ, 4DFR, and 24HR. All instruments were associated with considerable intake- and person-specific bias. Three 24HRs would provide the least attenuated risk estimate for sugars (attenuation factor, AF = 0.57), followed by FFQ (AF = 0.48) and 4DFR (AF = 0.32), in studies of energy-adjusted sugars and disease risk. In calibration models, self-reports explained little variation in true intake (5%-6% for absolute sugars and 7%-18% for sugars density). Adding participants' characteristics somewhat improved the percentage variation explained (16%-18% for absolute sugars and 29%-40% for sugars density).
  
  
  CONCLUSIONS
  None of the self-report instruments provided a good estimate of sugars intake, although overall 24HRs seemed to perform the best.
  
  
  CONCLUSIONS
  Assuming the calibrated sugars biomarker is unbiased, this analysis suggests that measuring the biomarker in a subsample of the study population for calibration purposes may be necessary for obtaining unbiased risk estimates in cancer association studies.
authors.affiliation: National Cancer Institute, Bethesda, Maryland. School of Nutrition and Health Promotion, Arizona State University, Phoenix, Arizona. natasha.tasevska@asu.edu.
authors.forename: Natasha
authors.initials: N
authors.lastname: Tasevska
authors.affiliation: National Cancer Institute, Bethesda, Maryland.
authors.forename: Douglas
authors.initials: D
authors.lastname: Midthune
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Lesley F
authors.initials: LF
authors.lastname: Tinker
authors.affiliation: National Cancer Institute, Bethesda, Maryland.
authors.forename: Nancy
authors.initials: N
authors.lastname: Potischman
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Johanna W
authors.initials: JW
authors.lastname: Lampe
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Marian L
authors.initials: ML
authors.lastname: Neuhouser
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Beasley
authors.affiliation: Department of Preventive Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Linda
authors.initials: L
authors.lastname: Van Horn
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Ross L
authors.initials: RL
authors.lastname: Prentice
authors.affiliation: National Cancer Institute, Bethesda, Maryland.
authors.forename: Victor
authors.initials: V
authors.lastname: Kipnis
mesh_terms: D000368:Aged; D002241:Carbohydrates / Q000652:urine*; D004034:Diet Surveys; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D009752:Nutritional Status; D011446:Prospective Studies; D057566:Self Report; D011795:Surveys and Questionnaires
chemical_list: D002241:Carbohydrates