Validation Information: FFQ (South Asian Women in Britain)
Sevak 2004
Validation of a food frequency questionnaire to assess macro and micro-nutrient intake among South Asians in the United Kingdom
Background: The South Asian population is one of the largest minority ethnic groups in the United Kingdom (UK), forming 2.7% of the UK population. Risk of diseases such as CHD, NIDDM is high in South Asians and risk of cancer low in this population compared both to the native UK population and other migrant groups. It is useful to investigate the experience of disease and dietary exposures for aetiological clues in South Asians. The FFQ was designed for a population-based case-control study of diet and breast cancer.
Aims: To validate a food frequency questionnaire (FFQ) to assess macro- and micronutrient intake among South Asians in the United Kingdom (UK).
Methods: A one-year long study of current diet was conducted using monthly telephone 24-hour recalls followed by administration of an interviewer-administered FFQ to ascertain usual diet during this period. General practices in the Thames and West Midlands regions, England were used to sequentially recruit 100 women from a larger random sample of South Asian migrants from general practitioners' patient lists participating as controls in a case-control study of diet and breast cancer.
Results: A total of 133 women were invited to achieve the final sample of 100 (76% response rate). The proportion of individuals classified by the two dietary assessment methods into the same or adjacent quartiles was high ranging from 65% (vitamin A) to 96% (protein). Misclassification into opposite quartiles was very low (0% to 5%), except for vitamin A (10%). Energyadjusted Spearman correlation coefficients were reasonable for almost all nutrients being highest for protein (0.76), NSP (0.71), folate (0.70) and cholesterol (0.69). Correction for within-person variation in monthly 24-hour recalls had little effect on the magnitude of the nutrient correlations between the FFQ and the 24-hour recalls. Calibration coefficients to correct relative risks for nutrient-disease associations were above 0.50 for most nutrients indicating that the degree of attenuation introduced by the FFQ would be acceptable.
Conclusions: This FFQ was specifically designed for South Asian women in the UK. Despite the diversity of diets, the FFQ had reasonable validity. The role of diet in breast cancer disease aetiology in this population is being assessed with this instrument.
Total number of nutrients validated: 16
Not all of the nutrients validated in the validation studies are included in the table below, as statistical data was only selected to be displayed for a number of nutrients, this included:
- Energy
- Fat
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Carbohydrates
- Protein
- Sugar
- Non‐starch polysaccharides(NSP)
- Sodium
- Calcium
- Iron
- Zinc
- Retinol
- Folate
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Energy
- Macronutrients: 8
- Micronutrients: 7
| Comparator | Lifestage | Sex | Nutrient Measured | Mean Difference | Standard Deviation | Correlation Coefficient | Cohen's Kappa Coefficient | Percentage Agreement | Percentage Agreement Categories | Lower Limits of Agreement | Upper Limits of Agreement |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 24hr Recall | Adults | Female Only | Energy (kcal) | 353 | 477 | 0.45 (S); 0.48 (P) | 0.30 | 43 | 4 | -600 | 1307 |
| Protein (g) | 8 | 15 | 0.55 (S); 0.57 (P) | 0.57 | 50 | 4 | -23 | 39 | |||
| Fat (g) | 19 | 26 | 0.53 (S); 0.57 (P) | 0.41 | 44 | 4 | -33 | 72 | |||
| Saturated Fat (g) | 5 | 8 | 0.60 (S); 0.60 (P) | 0.44 | 43 | 4 | -11 | 21 | |||
| MUFA (g) | 8 | 9 | 0.48 (S); 0.51 (P) | 0.34 | 46 | 4 | -9 | 25 | |||
| PUFA (g) | 9 | 11 | 0.52 (S); 0.57 (P) | 0.38 | 41 | 4 | -13 | 31 | |||
| Carbohydrates (g) | 39 | 62 | 0.39 (S); 0.43 (P) | 0.44 | 48 | 4 | -86 | 164 | |||
| Fibre (NSP) (g) | 7 | 6 | 0.43 (S); 0.39 (P) | 0.54 | 53 | 4 | -6 | 19 | |||
| Calcium (mg) | 173 | 284.6 | 0.45 (S); 0.45 (P) | 0.36 | 43 | 4 | -396.2 | 742.2 | |||
| Iron (mg) | 1.7 | 3.7 | 0.36 (S); 0.37 (P) | 0.41 | 43 | 4 | -5.7 | 9.1 | |||
| Folate (µg) | 47 | 65 | 0.44 (S); 0.49 (P) | 0.44 | 41 | 4 | -83 | 177 | |||
| Vitamin B12 (µg) | 0.2 (Geo) | 0.52 (S); 0.58 (P) | 0.34 | 40 | 4 | ||||||
| Vitamin C (mg) | 36.3 (Geo) | 0.40 (S); 0.45 (P) | 0.31 | 40 | 4 |
Some results have been calculated using statistical techniques based on the published data.
For further information on statistical terms click on Statistical tests used in validation studies
All correlations coefficients in the table are unadjusted unless stated otherwise. For adjusted correlation coefficients and other statistical methods used in the study e.g. paired t-tests, please read the validation articles.
- # Adjusted
- † Energy adjusted.
- ‡ For loge-transformed, energy-adjusted nutrient intakes.
- ^ Adjacent included.
- ᵟ Participants provided identical responses.
- (w) = Weighted.
Sevak L, Mangtani P, McCormack V, Bhakta D, Kassam-Khamis T, dos Santos Silva I. Validation of a food frequency questionnaire to assess macro-and micro-nutrient intake among South Asians in the United Kingdom. European journal of nutrition. 2004 Jun 1;43(3):160-8.