A bivariate measurement error model for nitrogen and potassium intakes to evaluate the performance of regression calibration in the European Prospective Investigation into Cancer and Nutrition study

Research output: Contribution to journalArticle

Abstract

Objectives: Within the European Prospective Investigation into Cancer and Nutrition (EPIC) study, the performance of 24-h dietary recall (24-HDR) measurements as reference measurements in a linear regression calibration model is evaluated critically at the individual (within-centre) and aggregate (between-centre) levels by using unbiased estimates of urinary measurements of nitrogen and potassium intakes. Methods: Between 1995 and 1999, 1072 study subjects (59% women) from 12 EPIC centres volunteered to collect 24-h urine samples. Log-transformed questionnaire, 24-HDR and urinary measurements of nitrogen and potassium intakes were analysed in a multivariate measurement error model to estimate the validity of coefficients and error correlations in self-reported dietary measurements. In parallel, correlations between means of 24-HDR and urinary measurements were computed. Linear regression calibration models were used to estimate the regression dilution (attenuation) factors. Results: After adjustment for sex, centre, age, body mass index and height, the validity coefficients for 24-HDRs were 0.285 (95% confidence interval: 0.194, 0.367) and 0.371 (0.291, 0.446) for nitrogen and potassium intakes, respectively. The attenuation factors estimated in a linear regression calibration model were 0.368 (0.228, 0.508) for nitrogen and 0.500 (0.361, 0.639) for potassium intakes; only the former was different from the estimate obtained using urinary measurements in the measurement error model. The aggregate-level correlation coefficients between means of urinary and 24-HDR measurements were 0.838 (0.637, 0.932) and 0.756 (0.481, 0.895) for nitrogen and potassium intakes, respectively. Conclusions: This study suggests that 24-HDRs can be used as reference measurements at the individual and aggregate levels for potassium intake, whereas, for nitrogen intake, good performance is observed for between-centre calibration, but some limitations are apparent at the individual level. European Journal of Clinical Nutrition (2009) 63, S179-S187; doi: 10.1038/ejcn.2009.80

Details

Authors
  • P. Ferrari
  • A. Roddam
  • M. T. Fahey
  • M. Jenab
  • C. Bamia
  • M. Ocke
  • P. Amiano
  • A. Hjartaker
  • C. Biessy
  • S. Rinaldi
  • I. Huybrechts
  • A. Tjonneland
  • C. Dethlefsen
  • M. Niravong
  • F. Clavel-Chapelon
  • J. Linseisen
  • H. Boeing
  • E. Oikonomou
  • P. Orfanos
  • D. Palli
  • M. Santucci de Magistris
  • H. B. Bueno-de-Mesquita
  • P. H. M. Peeters
  • C. L. Parr
  • T. Braaten
  • M. Dorronsoro
  • T. Berenguer
  • I. Johansson
  • A. A. Welch
  • E. Riboli
  • S. Bingham
  • N. Slimani
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Nutrition and Dietetics

Keywords

  • EPIC, measurement errors, urinary measurements, 24-h dietary recall, EPIC-SOFT
Original languageEnglish
Pages (from-to)S179-S187
JournalEuropean Journal of Clinical Nutrition
Volume63
Issue number4s
Publication statusPublished - 2009
Publication categoryResearch
Peer-reviewedYes