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Validation Information: Sheffield FFQ (Pregnant Women)
Validation of a food-frequency questionnaire for use in pregnancy
Objectives: As a part of an ongoing project to develop a nutritional screening tool, we evaluated the performance of a semi-quantitative food-frequency questionnaire (FFQ) in terms of validity in a Sheffield Caucasian pregnant population using two different statistical approaches - the correlation coefficient and the limits of agreement (LOA). The FFQ was designed specifically for pregnant women and previously used in a large-scale study.
Design: A validation study.
Setting: A community-based field study of a general population of pregnant women booked for their first antenatal appointment at the Jessop Wing, Royal Hallamshire Hospital, Sheffield, UK.
Subjects: One hundred and twenty-three women of different socio-economic status, aged between 17 and 43 years, provided complete dietary data.
Results: The validity of the FFQ was tested against a series of two 24-hour recalls. As expected, the intakes of all examined nutrients, except for iodine, carotene, vitamin E, biotin, vitamin C and alcohol, were higher when determined by the FFQ than when determined by 24-hour recall. Pearson's correlation coefficient between the two methods ranged from 0.19 (added sugar, zinc) to 0.47 (Englyst fibre). The LOA were broader for some of the nutrients, e.g. protein, Southgate fibre and alcohol, and an increasing lack of agreement between the two methods was identified with higher dietary intakes.
Conclusions: The FFQ gave useful estimates of the nutrient intakes of Caucasian pregnant women and appears to be a valid tool for categorising pregnant women according to dietary intake. The FFQ performed well for most nutrients and had acceptable agreement with the 24-hour recall.
Total number of nutrients validated: 36
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:
- Saturated Fat
- Mono-unsaturated Fat
- Poly-unsaturated Fat
- Non‐starch polysaccharides(NSP)
- Folic Acid
- Vitamin B12
- Vitamin C
- Fruit & Vegetables
- Urinary Nitrogen
To find information on the other validated nutrients please read the validation study.
- Macronutrients: 11
- Micronutrients: 24
|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)||377||551.25||0.26 (P)||64.2||5||-726||1480|
|Protein (g)||15||27||-0.14 (P)||54.5||5||-39||70|
|Fat (g)||20||30||0.28 (P)||67.5||5||-39||80|
|Saturated Fat (g)||11||14||0.23 (P)||64.2||5||-17||38|
|MUFA (g)||10||11||0.22 (P)||61.0||5||-12||32|
|PUFA (g)||5||8||-0.14 (P)||59.3||5||-10||20|
|Carbohydrates (g)||32||72||0.25 (P)||56.1||5||-112||177|
|Total Sugars (g)||6||46||0.19 (P)||60.2||5||-86||98|
|Fibre (NSP) (g)||3||5||0.47 (P)||70.7||5||-6||13|
|Sodium (mg)||106||1077.2||-0.07 (P)||58.5||5||-2048.3||2260.3|
|Calcium (mg)||61.1||353.8||-0.12 (P)||59.3||5||-646.4||768.6|
|Iron (mg)||3.2||4.0||0.32 (P)||61.0||5||-4.8||11.2|
|Zinc (mg)||1.6||2.8||0.19 (P)||55.3||5||-4||7.2|
|Retinol (µg)||92.4||216.8||-0.09 (P)||55.3||5||-341.2||526|
|Folate (µg)||49.5||77.7||0.29 (P)||59.3||5||-106.0||205.0|
|Vitamin B12 (µg)||1.1||2.1||-0.09 (P)||56.9||5||-3.0||5.2|
|Vitamin C (mg)||-0.7||48.2||0.42 (P)||62.6||5||-97.0||95.6|
|Fruit (% energy)||1||0.66 (P)|
|Vegetables (% energy)||13||0.64 (P)|
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.
Mouratidou T, Ford F, Fraser RB. Validation of a food-frequency questionnaire for use in pregnancy. Public health nutrition. 2006 Jun 1;9(04):515-22.