Reproducibility and feasibility of an online self-administered food frequency questionnaire for use among adult Norwegians

Reproducibility and comparison of a digital food frequency questionnaire (DIGIKOST-FFQ) assessing adherence to national diet and lifestyle recommendations

Background

We have developed a digital semi-quantitative food frequency and lifestyle questionnaire, the DIGIKOST-FFQ, based on the validated paper-based NORDIET-FFQ.

Objective

The study aims to investigate the reproducibility of the DIGIKOST-FFQ and to compare the DIGIKOST-FFQ against the NORDIET-FFQ for the adjusted questions for intakes of fruits, vegetables, whole grains, fish, meat, and dairy products.

Design

Participants were recruited from May to September 2021 through a random sample from the National Population Register and advertisements on Facebook in Norway. In the reproducibility study, the DIGIKOST-FFQ was completed twice by the participants, 1-2 months apart. In the comparison study, the DIGIKOST-FFQ was completed 1-2 months prior to the NORDIET-FFQ.

Results

In the reproducibility study, 317 individuals were included. For 12 out of 16 food groups there were no significant differences in intake estimations between the first and second DIGIKOST-FFQ administrations. A small but significant median difference was observed for fruits (6 g/day) and vegetables (24 g/day). Correlations were satisfactory for all items (r = 0.60-1.00), and in the cross-classification 85% of the participants were classified into the same or adjacent quartile for all items. The comparison study included 81 individuals. Compared to the NORDIET-FFQ a significant median difference was observed for fruits 29 g/day, vegetables 36 g/day, whole grains -10 g/day, and red meat -11 g/day, but not for fish, processed meat, or dairy products.

Conclusion

The DIGIKOST-FFQ was able to reproduce diet and lifestyle at the group level. An intended difference for the food groups where questions had been adjusted, was observed between DIGIKOST-FFQ and NORDIET-FFQ in the comparison study.

Validity and Reproducibility of an Electronic Food Frequency Questionnaire in Argentinian Adults

This study aimed to validate a semiquantitative electronic food frequency questionnaire (eFFQ) in estimating the intake of a comprehensive list of nutrients and bioactive compounds among adults from six regions of Argentina using multiple 24 h dietary recall (24HR) as a reference. A total of 163 adults completed two administrations of the eFFQ and four 24HRs. The paired t-test/Wilcoxon signed-rank test, Spearman/Pearson correlations, cross-classification, weighted kappa statistics, and Bland-Altman plots were employed to determine relative validity. To determine reproducibility, intraclass correlations (ICC), cross-classification, and weighted kappa statistics were calculated. For relative validity, crude correlations ranged from 0.15 to 0.57; energy adjustment and de-attenuation slightly improved most of these correlations. In cross-classification analysis, agreements within one quintile adjacent to exact agreement (EA ± 1) ranged from 52.2% to ~74%; extreme misclassifications were < 7%. For reproducibility, the crude ICC ranged from 0.29 to 0.85, showing moderate to good correlations for most nutrients. Cross-classification analysis showed agreement levels for the EA ± 1 quintile of 70.6% to 87.7%. Weighted kappa values ranged from 0.21 to 0.62. The results show that this eFFQ is relatively valid in ranking adults according to their nutrient intake and has an acceptable reproducibility, yet it slightly overestimates the intake of most nutrients.

Digital Food Frequency Questionnaire Assessing Adherence to the Norwegian Food-Based Dietary Guidelines and Other National Lifestyle Recommendations: Instrument Validation Study

BACKGROUND

Valid assessment tools are needed when investigating adherence to national dietary and lifestyle guidelines.

OBJECTIVE

The relative validity of the new digital food frequency questionnaire, the DIGIKOST-FFQ, against 7-day weighed food records and activity sensors was investigated.

METHODS

In total, 77 participants were included in the validation study and completed the DIGIKOST-FFQ and the weighed food record, and of these, 56 (73%) also used the activity sensors. The DIGIKOST-FFQ estimates the intake of foods according to the Norwegian food-based dietary guidelines (FBDGs) in addition to lifestyle factors.

RESULTS

At the group level, the DIGIKOST-FFQ showed good validity in estimating intakes according to the Norwegian FBDG. The median differences were small and well below portion sizes for all foods except "water" (median difference 230 g/day). The DIGIKOST-FFQ was able to rank individual intakes for all foods (r=0.2-0.7). However, ranking estimates of vegetable intakes should be interpreted with caution. Between 69% and 88% of the participants were classified into the same or adjacent quartile for foods and between 71% and 82% for different activity intensities. The Bland-Altman plots showed acceptable agreements between DIGIKOST-FFQ and the reference methods. The absolute amount of time in "moderate to vigorous intensity" was underestimated with the DIGIKOST-FFQ. However, estimated time in "moderate to vigorous intensity," "vigorous intensity," and "sedentary time" showed acceptable correlations and good agreement between the methods. The DIGIKOST-FFQ was able to identify adherence to the Norwegian FBDG and physical activity recommendations.

CONCLUSIONS

The DIGIKOST-FFQ gave valid estimates of dietary intakes and was able to identify individuals with different degrees of adherence to the Norwegian FBDG and physical activity recommendations. Moderate physical activity was underreported, water was overreported, and vegetables showed poor correlation, which are important to consider when interpreting the data. Good agreement was observed between the methods in estimating dietary intakes and time in "moderate to vigorous physical activity," "sedentary time," and "sleep."

Relative Validity and Reproducibility of a Web-Based Semi-Quantitative Food Frequency Questionnaire in the Danish Diet, Cancer, and Health-Next Generations MAX Study

The food frequency questionnaire (FFQ) is designed to capture an individual's habitual dietary intake and is the most applied method in nutritional epidemiology. Our aim was to assess the relative validity and reproducibility of the FFQ used in the Diet, Cancer, and Health-Next Generations cohort (DCH-NG). We included 415 Danish women and men aged 18-67 years. Spearman's correlations coefficients, Bland-Altman limits of agreement and cross-classification between dietary intakes estimated from the FFQ administered at baseline (FFQ_baseline), and the mean of three 24-h dietary recalls (24-HDRs) and the FFQ administered after 12 months (FFQ_{12 months}) were determined. Nutrient intakes were energy-adjusted by Nutrient Density and Residual methods. Correlation coefficients ranged from 0.18-0.58 for energy and energy-adjusted nutrient intakes, and the percentage of participants classified into the same quartile ranged from 28-47% between the FFQ_baseline and the 24-HDRs. For the FFQ_{12 months} compared with FFQ_baseline, correlation coefficients ranged from 0.52-0.88 for intakes of energy, energy-adjusted nutrients, and food groups, and the proportion of participants classified into the same quartiles ranged from 43-69%. Overall, the FFQ provided a satisfactory ranking of individuals according to energy, nutrient, and food group intakes, making the FFQ suitable for use in epidemiological studies investigating diet in relation to disease outcomes.

A Short Digital Food Frequency Questionnaire (DIGIKOST-FFQ) Assessing Dietary Intake and Other Lifestyle Factors Among Norwegians: Qualitative Evaluation With Focus Group Interviews and Usability Testing

Background

In-person dietary counseling and interventions have shown promising results in changing habits toward healthier lifestyles, but they are costly to implement in large populations. Developing digital tools to assess individual dietary intake and lifestyle with integrated personalized feedback systems may help overcome this challenge. We developed a short digital food frequency questionnaire, known as the DIGIKOST-FFQ, to assess diet and other lifestyle factors based on the Norwegian Food-Based Dietary Guidelines. The DIGIKOST-FFQ includes a personalized feedback system, the DIGIKOST report, that benchmarks diet and lifestyle habits. We used qualitative focus group interviews and usability tests to test the feasibility and usability of the DIGIKOST application.

Objective

We aimed to explore attitudes, perceptions, and challenges in completing the DIGIKOST-FFQ. We also investigated perceptions and understanding of the personalized feedback in the DIGIKOST report and the technical flow and usability of the DIGIKOST-FFQ and the DIGIKOST report.

Methods

Healthy individuals and cancer survivors were invited to participate in the focus group interviews. The transcripts were analyzed using thematic analysis. Another group of healthy individuals completed the usability testing, which was administered individually by a moderator and 2 observers. The results were analyzed based on predefined assignments and discussion with the participants about the interpretation of the DIGIKOST report and technical flow of the DIGIKOST-FFQ.

Results

A total of 20 individuals participated in the focus group interviews, divided into 3 groups of healthy individuals and 3 groups of cancer survivors. Each group consisted of 3 to 4 individuals. Five main themes were investigated: (1) completion time (on average 19.1, SD 8.3, minutes, an acceptable duration), (2) layout (participants reported the DIGIKOST-FFQ was easy to navigate and had clear questions but presented challenges in reporting dietary intake, sedentary time, and physical activity in the last year), (3) questions (the introductory questions on habitual intake worked well), (4) pictures (the pictures were very helpful, but some portion sizes were difficult to differentiate and adding weight in grams would have been helpful), and (5) motivation (users were motivated to obtain personalized feedback). Four individuals participated in the usability testing. The results showed that the users could seamlessly log in, give consent, fill in the DIGIKOST-FFQ, and receive, print, and read the DIGIKOST report. However, parts of the report were perceived as difficult to interpret.

Conclusions

The DIGIKOST-FFQ was overall well received by participants, who found it feasible to use; however, some adjustments with regard to reporting dietary intake and lifestyle habits were suggested. The DIGIKOST report with personalized feedback was the main motivation to complete the questionnaire. The results from the usability testing revealed a need for adjustments and updates to make the report easier to read.