Fig 1.
Study design and time frame used in this study.
FFQ was administrated at the baseline (FFQ1) and one year later (FFQ2) at rural health clinics by trained interviewers with a face-to face approach. Six times 3-day 24-hour recalls (24HRs) surveys were performed between the two FFQs in every two month. The first 24HRs were performed one month later after the FFQ1. Several interviewers visited to participants with local dialect. All participants were asked to recall all foods (including recipes/ingredients of mixed dishes) and drinks that they consumed from the last day (22:00) to next day (22:00) on the 24-hour dietary recall questionnaires in three consecutive days (including two weekdays and one weekend day). The reliability of FFQ was assessed by comparing the dietary pattern scores between FFQ1 and FFQ2. The Validity of the FFQ was assessed by comparing the dietary pattern scores between FFQs and 24HRs.
Table 1.
Food and drinks in the food frequency questionnaire.
Table 2.
Characteristics of participants in the study.
Table 3.
Average daily intakes of eighteen dietary groups from FFQ1, FFQ2 and 24HRs.
Table 4.
Rotated Factor loadings matrix for two dietary patterns identified from FFQ1, FFQ2 and 24HRs.
Table 5.
Correlation coefficients for dietary pattern scores derived from FFQ1, FFQ2 and 24HRs.
Table 6.
Percentage agreement, kappa statistic and limits of agreement for dietary pattern scores derived from FFQ1, FFQ2 and 24HRs.
Fig 2.
Bland–Altman plots for scores of prudent pattern and processed food pattern derived from FFQ1and FFQ2.
A: Prudent pattern; B, Processed food pattern; FFQ1-FFQ2, the patterns score difference of FFQ1 and FFQ2; (FFQ1+FFQ2)/2, average pattern scores of FFQ1 and FFQ2. The solid line represents the mean difference (FFQ1-FFQ2) and the dash lines represent the limits of agreements (mean difference ± 1.96 standard deviations).
Fig 3.
Bland–Altman plots for scores of prudent pattern and processed food pattern derived from two FFQs and 24HRs.
A, Prudent pattern (FFQ1 vs. 24HRs); B, Processed food pattern (FFQ1 vs. 24HRs); C, Prudent pattern (FFQ2 vs. 24HRs); D, Processed food pattern (FFQ2 vs. 24HRs); FFQs- 24HRs, the pattern score difference of FFQs and 24HRs; (FFQs + 24HRs)/2, average pattern scores of FFQs and 24HRs. The solid line represents the mean difference (FFQs-24HRs) and the dash lines represent the limits of agreements (mean difference ± 1.96 standard deviations).