title: Pooled results from 5 validation studies of dietary self-report instruments using recovery biomarkers for potassium and sodium intake.
abstract: We pooled data from 5 large validation studies (1999-2009) of dietary self-report instruments that used recovery biomarkers as referents, to assess food frequency questionnaires (FFQs) and 24-hour recalls (24HRs). Here we report on total potassium and sodium intakes, their densities, and their ratio. Results were similar by sex but were heterogeneous across studies. For potassium, potassium density, sodium, sodium density, and sodium:potassium ratio, average correlation coefficients for the correlation of reported intake with true intake on the FFQs were 0.37, 0.47, 0.16, 0.32, and 0.49, respectively. For the same nutrients measured with a single 24HR, they were 0.47, 0.46, 0.32, 0.31, and 0.46, respectively, rising to 0.56, 0.53, 0.41, 0.38, and 0.60 for the average of three 24HRs. Average underreporting was 5%-6% with an FFQ and 0%-4% with a single 24HR for potassium but was 28%-39% and 4%-13%, respectively, for sodium. Higher body mass index was related to underreporting of sodium. Calibration equations for true intake that included personal characteristics provided improved prediction, except for sodium density. In summary, self-reports capture potassium intake quite well but sodium intake less well. Using densities improves the measurement of potassium and sodium on an FFQ. Sodium:potassium ratio is measured much better than sodium itself on both FFQs and 24HRs.
authors: Laurence S
authors: LS
authors: Freedman
authors: John M
authors: JM
authors: Commins
authors: James E
authors: JE
authors: Moler
authors: Walter
authors: W
authors: Willett
authors: Lesley F
authors: LF
authors: Tinker
authors: Amy F
authors: AF
authors: Subar
authors: Donna
authors: D
authors: Spiegelman
authors: Donna
authors: D
authors: Rhodes
authors: Nancy
authors: N
authors: Potischman
authors: Marian L
authors: ML
authors: Neuhouser
authors: Alanna J
authors: AJ
authors: Moshfegh
authors: Victor
authors: V
authors: Kipnis
authors: Lenore
authors: L
authors: Arab
authors: Ross L
authors: RL
authors: Prentice
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D015982:Bias; D015415:Biomarkers / Q000652:urine; D015992:Body Mass Index; D004034:Diet Surveys / Q000379:methods / Q000706:statistics & numerical data*; D004522:Educational Status; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D017419:Potassium, Dietary / Q000652:urine*; D057566:Self Report; D017678:Sex Distribution; D012982:Sodium, Dietary / Q000652:urine*; D014481:United States; D054928:Validation Studies as Topic
chemical_list: D015415:Biomarkers; D017419:Potassium, Dietary; D012982:Sodium, Dietary
keywords: 24-hour recall; attenuation factors; calibration models; dietary measurement error; food frequency questionnaire; underreporting