Checking for completeness of 24-h urine collection using para-Amino benzoic acid not necessary in the Observing Protein and Energy Nutrition study

A. F. Subar, D. Midthune, N. Tasevska, V. Kipnis, L. S. Freedman

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


Background/Objectives:The orally administered para-Amino benzoic acid (PABA) is known to have near 100% excretion in urine and is used as a measure of 24-h urine collection completeness (referred to as PABAcheck). The purpose was to examine the effect of including urine collections deemed incomplete based on PABAcheck in a dietary measurement error study.Subjects/Methods:The Observing Protein and Energy Nutrition (OPEN) study was conducted in 1999-2000 and included 484 men and women aged 40-69 years. A food frequency questionnaire and 24-h dietary recalls were evaluated using recovery biomarkers that included urinary nitrogen and potassium from two 24-h urine collections. Statistical modeling determined the measurement error properties of dietary assessment instruments. In the original analyses, PABAcheck was used as a measure of complete urine collection; incomplete collections were either excluded or adjusted to acceptable levels. The OPEN data were reanalyzed including all urine collections and by using criteria based on self-reported missing voids to assess the differences.Results:Means and coefficients of variation for biomarker-based protein and potassium intakes, and measurement error model-based correlations and attenuation factors were similar regardless of whether PABAcheck or missed voids were considered.Conclusion:PABAcheck may not be required in large population-based biomarker studies. However, until there are more analyses evaluating the necessity of a PABAcheck, it is recommended that PABA be given to all participants, but not necessarily analyzed. Then, PABAcheck could be used selectively as a marker of completeness among the collections in which low levels of biomarker are detected or for which noncompliance is suspected.

Original languageEnglish
Pages (from-to)863-867
Number of pages5
JournalEuropean Journal of Clinical Nutrition
Issue number8
StatePublished - Aug 2013
Externally publishedYes

Bibliographical note

Funding Information:
This work was funded by the US National Cancer Institute.


  • diet
  • nutrition assessment
  • statistical bias
  • urine specimen collection


Dive into the research topics of 'Checking for completeness of 24-h urine collection using para-Amino benzoic acid not necessary in the Observing Protein and Energy Nutrition study'. Together they form a unique fingerprint.

Cite this