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.
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.
Authors: Sandra P Crispim; Anouk Geelen; Jeanne H M de Vries; Heinz Freisling; Olga W Souverein; Paul J M Hulshof; Marga C Ocke; Hendriek Boshuizen; Lene F Andersen; Jiri Ruprich; Willem De Keyzer; Willem De Keizer; Inge Huybrechts; Lionel Lafay; Maria S de Magistris; Fulvio Ricceri; Rosario Tumino; Vittorio Krogh; H Bas Bueno-de-Mesquita; Joline W J Beulens; Marie-Christine Boutron-Ruault; Androniki Naska; Francesca L Crowe; Heiner Boeing; Alison McTaggart; Rudolf Kaaks; Pieter Van't Veer; Nadia Slimani Journal: Eur J Nutr Date: 2011-12-06 Impact factor: 5.614
Authors: Laurence S Freedman; John M Commins; Walter Willett; Lesley F Tinker; Donna Spiegelman; Donna Rhodes; Nancy Potischman; Marian L Neuhouser; Alanna J Moshfegh; Victor Kipnis; David J Baer; Lenore Arab; Ross L Prentice; Amy F Subar Journal: Am J Epidemiol Date: 2017-07-01 Impact factor: 4.897
Authors: Saijuan Zhang; Douglas Midthune; Patricia M Guenther; Susan M Krebs-Smith; Victor Kipnis; Kevin W Dodd; Dennis W Buckman; Janet A Tooze; Laurence Freedman; Raymond J Carroll Journal: Ann Appl Stat Date: 2011-06-01 Impact factor: 2.083
Authors: Pietro Ferrari; Heinz Freisling; Eric J Duell; Rudolf Kaaks; Leila Lujan-Barroso; Françoise Clavel-Chapelon; Marie-Christine Boutron-Ruault; Laura Nailler; Silvia Polidoro; Amalia Mattiello; Domenico Palli; Rosario Tumino; Sara Grioni; Sven Knüppel; Anne Tjønneland; Anja Olsen; Kim Overvad; Philippos Orfanos; Michail Katsoulis; Antonia Trichopoulou; Jose Ramón Quirós; Eva Ardanaz; José María Huerta; Pilar Amiano Etxezarreta; María José Sánchez; Francesca Crowe; Kay-Tee Khaw; Nicholas J Wareham; Marga Ocke; Bas Bueno-de-Mesquita; Petra H M Peeters; Ulrika Ericson; Elisabet Wirfält; Göran Hallmans; Ingegerd Johansson; Dagrun Engeset; Geneviève Nicolas; Valentina Gallo; Teresa Norat; Elio Riboli; Nadia Slimani Journal: Eur J Nutr Date: 2012-11-01 Impact factor: 5.614