TY - JOUR
T1 - 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
AU - Ferrari, P.
AU - Roddam, A.
AU - Fahey, M. T.
AU - Jenab, M.
AU - Bamia, C.
AU - Ocke, M.
AU - Amiano, P.
AU - Hjartaker, A.
AU - Biessy, C.
AU - Rinaldi, S.
AU - Huybrechts, I.
AU - Tjonneland, A.
AU - Dethlefsen, C.
AU - Niravong, M.
AU - Clavel-Chapelon, F.
AU - Linseisen, J.
AU - Boeing, H.
AU - Oikonomou, E.
AU - Orfanos, P.
AU - Palli, D.
AU - de Magistris, M. Santucci
AU - Bueno-de-Mesquita, H. B.
AU - Peeters, P. H. M.
AU - Parr, C. L.
AU - Braaten, T.
AU - Dorronsoro, M.
AU - Berenguer, T.
AU - Gullberg, Bo
AU - Johansson, I.
AU - Welch, A. A.
AU - Riboli, E.
AU - Bingham, S.
AU - Slimani, N.
PY - 2009
Y1 - 2009
N2 - 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
AB - 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
KW - EPIC
KW - measurement errors
KW - urinary measurements
KW - 24-h dietary recall
KW - EPIC-SOFT
U2 - 10.1038/ejcn.2009.80
DO - 10.1038/ejcn.2009.80
M3 - Article
C2 - 19888273
VL - 63
SP - S179-S187
JO - European Journal of Clinical Nutrition
JF - European Journal of Clinical Nutrition
SN - 1476-5640
IS - 4s
ER -