The research team of Bogers et al (2003) has conducted a research entitled “Using a Correction Factor to Correct for Overreporting in a Food Frequency Questionnaire Does Not Improve Biomarker-Assessed Validity of Estimates for Fruit and Vegetable Consumption”. The following section presents the rationale for the study, methodology, results, and conclusion to summarize the journal article. Rationale The main thrust of the study is to be able to compute for correction factors so as to rectify the overreporting of food and vegetable (FV) consumption.
This was carried out through the deployment of FV consumption via questionnaire. In a nutshell, the research has compared the capacity to rank people on the basis of their FV consumption answers (as reported through the items in the questionnaire) to individual questions and also of rectified and uncorrected projections of food and vegetables. Methodology The respondents of the study consisted of 161 healthy women in their middle age who were asked to accomplish the FV instrument about their FV consumption in the past month and from whom one fasting blood sample was collected.
For the computation of the correction factors, “the reported frequency on a summary question divided by the summed frequencies of all items in the category. FV consumption has been validated through the use of carotenoids as biomarkers. Results There were statistically significant Spearman’s correlation coefficients that were computed for both food and vegetable consumption and biomarkers present. The individual summary projections of cooked, raw and total vegetable consumption registered stronger relationships with biomarkers than with overall (i. e. sum) projections.
Moreover, there was no such distinction in the strength of correlation for fruits. To test the utility of the correction factor, it was used for carrot and cabbage consumption and it was found that the strength of relationship with biomarkers decreased upon application (for individual carrot consumption and total cabbage consumption vs. biomarkers). There was no such change noted upon application of the factor to the following: Brussels sprouts, broccoli, cauli flower, and citrus.
Conclusion Bogers et al (2003) put forth that the use of summary questions are adequate for ranking respondents’ FV consumption. In addition, it has been suggested that the correction for overreporting of individual fruits and vegetables may not be commendable when ranking respondents on their consumption of each of these. Article 2: Summary The second article was a research carried out by Kipnis et al (2003) entitled “Structure of Dietary Measurement Error: Results of the OPEN Biomarker Study”.
The following section explains the rationale of the study, its methodology, results, and conclusion. Rationale The main thrust of the study was to investigate the effectiveness of multiple-day food records or 24-hour dietary recalls (24HRs) as regards its proneness to measurement error. These instruments are conventionally utilized for the calibration of Food Frequency Questionnaires (FFQs). Pragmatically, they are used to validate the outcomes of epidemiological researches on nutrition.
If there is apt adjustment, “errors in the adopted reference instrument [will] be independent of those in the FFQ and true intake”. Method Kipnis et al (2003) have used data collected from the Observing Protein and Energy Nutrition (OPEN) research which has been carried out from September 1999 to March 2000. Doubly labeled water and urinary nitrogen have been used as biomarkers. Data were collected from 484 healthy participants from Maryland. Results
The outcomes of the study indicate that the FFQ leads to substantial decrease in the projected disease risk for protein and energy consumption. For instance, a relative risk of 2 is presented by the FFQ only as 1. 1 or even lower. The results suggest that the use of the 24HR as a benchmark tool may gravely decrease the value of energy-adjusted protein. Conclusion Kipnis et al (2003) conclude that the outcomes of all epidemiologic research which have used this instrument for measuring the relationships of diet and disease need to be seriously reviewed.