Validity and Reliability of Semiquantitative Food Frequency Questionnaires for Assessing Nutrient Intake among Preschool Children in Northwest China
Table 3
Test-retest reliability of FFQs for preschool children.
Item (units/d)
FFQ 1
FFQ 2
value
SCC
ICC
%difference
Median
(P25–P75)
Median
(P25–P75)
Energy (kcal)
1669.69
(1337.62, 1951.31)
1935.73
(1542.00, 2167.31)
0.063
0.832
0.882
15.9
Carbohydrates (g)
215.49
(170.90, 255.88)
243.09
(195.28, 287.05)
0.231
0.599
0.669
12.9
Protein (g)
70.00
(55.19, 86.85)
79.02
(62.17, 92.15)
0.506
0.615
0.688
13.1
Fat (g)
48.87
(39.29, 63.87)
55.75
(40.16, 73.56)
0.162
0.622
0.613
14.5
Dietary fibre (g)
19.00
(14.68, 25.60)
22.09
(17.10, 28.04)
0.245
0.528
0.607
16.9
Cholesterol (mg)
365.08
(243.34, 468.42)
362.61
(243.34, 498.81)
0.304
0.547
0.553
-0.7
Vitamin A (IU)
993.54
(708.51, 1353.43)
1074.51
(823.16, 1493.34)
0.426
0.434
0.462
8.6
Thiamin (mg)
0.90
(0.67, 1.05)
0.94
(0.74, 1.13)
0.168
0.623
0.611
4.8
Riboflavin (mg)
1.39
(1.18, 1.74)
1.50
(1.23, 1.92)
0.242
0.561
0.551
8.5
Vitamin C (mg)
78.82
(52.41, 117.47)
94.57
(67.56, 127.50)
0.043
0.349
0.343
21.8
Vitamin E (mg)
13.95
(10.42, 20.33)
15.36
(11.85, 21.24)
0.089
0.493
0.483
11.1
Niacin (mg)
16.46
(12.92, 20.55)
18.11
(14.82, 22.89)
0.423
0.410
0.432
11.1
Calcium (mg)
641.20
(501.39, 808.48)
677.51
(549.22, 880.49)
0.476
0.551
0.436
6.3
Iron (mg)
25.29
(19.75, 34.55)
28.81
(22.57, 36.71)
0.135
0.556
0.521
15.7
Zinc (mg)
6.10
(4.70, 7.87)
6.92
(5.30, 8.52)
0.431
0.440
0.429
15.3
Phosphorus (mg)
886.31
(725.71, 1106.63)
942.74
(754.89, 1211.73)
0.542
0.589
0.508
7.3
Sodium (mg)
597.48
(492.03, 738.04)
694.44
(521.91, 866.27)
0.038
0.631
0.675
18.8
Selenium (mg)
19.31
(14.36, 28.57)
23.90
(15.52, 32.13)
0.046
0.222
0.282
27.8
Magnesium (mg)
372.18
(301.82, 515.16)
452.32
(349.58, 589.40)
0.025
0.528
0.546
25.4
value of t test between FFQ1 and FFQ2. SCC: Spearman’s correlation coefficient; ICC: intraclass correlation coefficient; %CC: the percentage of correctly classified; %GM: the percentage of grossly misclassified; %difference in nutrient intakes between FFQ 1 and FFQ 2; %difference = (FFQ 2 − FFQ 1/FFQ 1) 100%.
