Tool Library Tool Information
Validation Information: FFQ (Protein and potassium)
Comparison of approaches to correct intake-health associations for FFQ measurement error using a duplicate recovery biomarker and a duplicate 24h dietary recall as a reference method
Objective: To illustrate the impact of intake-related bias in FFQ and 24-hr recall and correlated errors between these methods, on intake–health associations. Design: Dietary intake was assessed by a 180-item semi-quantitative FFQ and two 24-hr recalls. Urinary N and urinary K were estimated from two 24 -hr urine samples. We compared four scenarios to correct associations for errors in an FFQ estimating protein and K intakes. Setting: Wageningen, the Netherlands. Subjects: Fifty-nine men and ﬁfty-eight women aged 45–65 years. Results: For this FFQ, measurement error weakened a true relative risk of 2.0 to 1.4 for protein and 1.5 for K. As compared with calibration to duplicate recovery biomarkers (i.e. the preferred scenario 1), estimating a validity coefﬁcient using this duplicate biomarker resulted in overcorrected associations, caused by intake-related bias in the FFQ (scenario 2). The correction factor based on a triad using biomarkers and 24-hr recall was hampered by this intake-related bias and by correlated errors between FFQ and 24-hr recall, and in this population resulted in a nearly perfect correction for protein but an overcorrection for K (scenario 3). When the 24-hr recall was used for calibration, only a small correction was done, due to correlated errors between the methods and intake-related bias in the 24-hr recall (scenario 4).Conclusions: Calibration to a gold standard reference method is the preferred approach to correct intake–health associations for FFQ measurement error. If it is not possible to do so, using the 24-hr recall as reference method only partly removes the errors, but may result in improved intake–health associations.
Total number of nutrients validated: 2
Not all of the nutrients validated in the validation studies are included in the table below, as statistical data was only selected to be displayed for a number of nutrients, this included:
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Non‐starch polysaccharides(NSP)
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Macronutrients: 1
- Micronutrients: 1
|Comparator||Lifestage||Sex||Nutrient Measured||Mean Difference||Standard Deviation||Correlation Coefficient||Cohen's Kappa Coefficient||Percentage Agreement||Percentage Agreement Categories||Lower Limits of Agreement||Upper Limits of Agreement|
|24hr Recall||Adults (45-65 years)||Male Only||Protein||-24.5||-7.7|
|24hr Recall||Adults (45-65 years)||Female Only||Protein||-11.3||-5.6|
Some results have been calculated using statistical techniques based on the published data.
For further information on statistical terms click on Statistical tests used in validation studies
All correlations coefficients in the table are unadjusted unless stated otherwise. For adjusted correlation coefficients and other statistical methods used in the study e.g. paired t-tests, please read the validation articles.
- # Adjusted
- † Energy adjusted.
- ‡ For loge-transformed, energy-adjusted nutrient intakes.
- ^ Adjacent included.
- ᵟ Participants provided identical responses.
- (w) = Weighted.
Geelen A, Souverein O.W, Busstra M.C, de Vries J.H.M. & van t Veer P. Comparison of approaches to correct intake health associations for FFQ measurement error using a duplicate recovery biomarker and a duplicate 24h dietary recall as a reference method. (2014. Public Health Nutrition. 18 (2) 226-233