1. Is a subgroup assessment sufficient? Department of Epidemiology German Institute of Human Nutrition Potsdam-Rehbrücke

2. Scenario CriteriaWhole study (n=30,000) Random sample (n=1,500) Assessment method 2 x 24 HDR + 1 x Food Propensity Questionnaire Staff requirements for 24 HDRs 25 interviewers1 interviewer Estimated total costs of dietary assessment € 750.000€ 30.000

3. Objective Comparison of food intake distributions derived by different statistical methods

4. Study design EPIC-Potsdam-Calibration Study II random sample of EPIC-Potsdam-Cohort: – n= 393; 197 men and 196 women dietary assessment methods: – 2 x 24HDRs by telephone, randomized over one year – 1 x 102 food-item FFQ („food propensity questionnaire“) at the end of the year Nöthlings et al.(2007): Fitting portion sizes in self-administered Food frequency questionnaire. The Journal of Nutrition, 137: 2781-2786

5. Statistical analysis Hoffmann et al.(2002): Estimating the distribution of usual dietary intake by short-term measurements. European Journal of Clinical Nutrition, 56, Suppl 2, S53-S62 food groups: fresh fruits (often); fish (occasionally); breakfast cereals (rarely) 2-day-means Multiple-source method – 2 x 24 HDRs and 1 x FFQ frequency as covariate Linear regression calibration methods – Simple linear regression calibration – Linear regression calibration with correction of intraindividual variance

6. Results: Fresh fruits Fresh fruits 0 MethodP5P10P25P50P75P90P95Arithmetic meanStandard deviation 2-day means [g/day] 07103234395513678265203 Multiple Source [g/day] 67102145239350469544264148 Simple linear Calibration 1 [g/day] 15016118124532440043226593 Linear Calibration 2 [g/day] 74100150232346470542265154 0 N: 393 1 simple linear regression calibration 2 linear regression calibration with correction of intraindividual variance

7. Results: Fish Fish 0 MethodP5P10P25P50P75P90P95Arithmetic meanStandard deviation 2-day means [g/day] 0000451001272848 Multiple Source [g/day] 4712194461712823 Linear Calibration 1 [g/day] 19202225313847289 Linear Calibration 3 [g/day] 2310193759872827 0 N: 393 1 simple linear regression calibration 2 linear regression calibration with correction of intraindividual variance

8. Results: Breakfast cereals Breakfast Cereals 0 MethodP5P10P25P50P75P90P95Arithmetic meanStandard deviation 2-day means [g/day] 00000625311 Multiple Source [g/day] 00001122038 Linear Calibration 1 [g/day] 0000391836 Linear Calibration 3 [g/day] 00003112238 0 N: 393 1 simple linear regression calibration 2 linear regression calibration with correction of intraindividual variance

9. Correlations Pearson Correlation Coefficients MethodFresh fruitsFishBreakfast cereals Multiple Source vs FFQ0.95 <0.0001 0.94 <0.0001 0.93 <0.0001

10. Summary 1.There is a high correlation between FFQ and MSM 2.Subgroup assessment applying the Multiple source method and standardization of the FFQs of the whole cohort according to the MSM distribution moments?

11. Thank you for your attention!