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Table 2 Reproducibility of energy and nutrient intake between FFQ1 and FFQ2 (n = 139)

From: Reliability and validity of a semi-quantitative food frequency questionnaire: dietary intake assessment among multi-ethnic populations in Northwest China

Nutrient

FFQ1

FFQ2

ICC

Kappa

SCC

Median

P25, P75

Median

P25, P75

95% CI

Energy (Kcal)

2270.1

2101.3, 2481.9

2283.8

2089.8, 2508.1

0.78 (0.69, 0.81)

0.49**

0.84**

Protein (g)

64.3

59.5, 67.1

65.3

58.1, 71.2

0.69 (0.58, 0.78)

0.33**

0.74**

Fat (g)

72.5

68.1, 75.5

70.8

66.1, 79.2

0.78 (0.70, 0.84)

0.36**

0.78**

Carbohydrates (g)

344.5

328.6, 357.5

337.4

311.6, 369.3

0.59 (0.46, 0.70)

0.25**

0.67**

Dietary fiber (g)

14.0

12.5, 15.0

13.5

10.3, 16.0

0.43 (0.27, 0.57)

0.12*

0.49**

Cholesterol (mg)

270.8

254.1, 292.0

263.0

240.7, 303.8

0.71 (0.63, 0.82)

0.51**

0.77**

Vitamin A (μg RE)

544.5

465.9, 579.4

546.0

441.2, 597.4

0.77 (0.65, 0.80)

0.52**

0.81**

Vitamin D (μg)

10.5

8.5, 13.0

8.5

6.0, 12.3

0.51 (0.25, 0.67)

0.30**

0.63**

Vitamin E (mg)

13.5

11.5, 15.0

12.5

9.6, 13.8

0.45 (0.30, 0.58)

0.18*

0.51**

Vitamin K (μg)

67.8

60.0, 75.5

65.8

50.8, 76.9

0.69 (0.56, 0.79)

0.41**

0.83**

Thiamin (mg)

0.9

0.7, 1.1

0.7

0.5, 1.1

0.74 (0.62, 0.82)

0.24**

0.68**

Riboflavin (mg)

0.9

0.7, 1.2

0.8

0.7, 1.0

0.65 (0.48, 0.77)

0.37**

0.71**

Vitamin B6 (mg)

1.1

0.8, 1.3

1.0

0.7, 1.1

0.60 (0.45, 0.71)

0.36**

0.64**

Vitamin B12 (μg)

1.6

1.1, 2.1

1.3

0.5, 2.2

0.71 (0.62, 0.82)

0.36**

0.81**

Vitamin C (mg)

81.8

73.5, 92.9

57.3

44.6, 82.6

0.43 (-0.07, 0.72)

0.29**

0.70**

Folate (μg)

382.5

331.5, 425.3

379.3

296.9, 466.9

0.72 (0.62, 0.80)

0.43**

0.66**

Calcium (mg)

612.0

513.8, 714.4

619.5

446.3, 724.9

0.76 (0.66, 0.83)

0.64**

0.81**

Phosphorus (mg)

716.0

644.5, 834.5

740.3

592.3, 882.3

0.73 (0.63, 0.80)

0.40**

0.82**

Potassium (mg)

1767.8

1676.5, 1979.4

1612.3

1427.9, 1934.9

0.71 (0.57, 0.80)

0.51**

0.79**

Sodium (mg)

1662.5

1528.1, 1832.8

1503.8

1299.1, 1838.1

0.61 (0.54, 0.74)

0.46**

0.73**

Magnesium (mg)

289.5

276.1, 311.4

256.5

223.9, 289.4

0.39 (0.21, 0.49)

0.21**

0.43**

Iron (mg)

12.5

10.1, 13.5

12.5

9.5, 15.3

0.61 (0.35, 0.74)

0.57**

0.76**

Iodine (μg)

86.0

74.0, 105.9

82.0

57.5, 125.8

0.68 (0.57, 0.77)

0.46**

0.76**

Zinc (mg)

11.5

10.5, 13.5

12.5

9.5, 15.6

0.51 (0.36, 0.63)

0.35**

0.65**

Selenium (μg)

58.5

53.0, 68.0

61.3

54.5, 70.8

0.48 (0.39, 0.61)

0.52**

0.64**

Copper (mg)

1.0

0.9, 1.2

0.7

0.5, 1.2

0.43 (0.24, 0.58)

0.11*

0.55**

Niacinamide (mg)

273.5

260.5, 288.5

256.5

238.1, 279.3

0.63 (0.51, 0.73)

0.22**

0.57**

Choline (mg)

430.5

364.1, 476.5

445.3

314.6, 514.1

0.57 (0.46, 0.68)

0.39**

0.62**

  1. Daily intakes of nutrients estimated by two FFQs; P25, P75, 25th–75th percentile
  2. ICCs, intra-class correlation coefficients; CI, confidence interval; SCC, Spearman correlation coefficients
  3. Statistical significance was accepted with *P < 0.05 (2-tailed). **P < 0.01