U E MacIntyre1, C S Venter, H H Vorster. 1. Department of Paediatrics and Child Health, Medical University of Southern Africa, South Africa. paeds@iweb.co.za
Abstract
OBJECTIVE: To develop and assess the reproducibility of a quantitative food frequency questionnaire (QFFQ) sensitive to the culture of the African population of the North West Province, South Africa. DESIGN: A cross-sectional study. SETTING: A community-based field study in a population stratified according to level of urbanization from deep rural to urban upper class. SUBJECTS: A total of 144 (99 women and 45 men) residents of the North West Province, aged between 15 and 65 years. participated in the study. METHODS: A culture-sensitive. 145-item interviewer-administered QFFQ was designed to cover the whole diet. Portion sizes were estimated from a food portion photograph book (FPPB) showing foods in three portion sizes. The QFFQ was administered twice, 6-12 weeks apart. RESULTS: Spearman rank correlation coefficients between the two administrations varied from 0.14 for calcium to 0.75 for alcohol. The mean percentage difference between intakes was 8.5 (standard deviation= 9.9). Energy. protein, carbohydrate and calcium gave differences within 10%. Few significant differences among correlation coefficients or percentage difference for gender, age group or strata of urbanization were present. Bland-Altman plots showed significant proportional bias for protein, fibre and vitamin C. More than 70% of the participants were classified into adjacent quintiles for all nutrients. For food groups, correlation coefficients ranged from 0.25 for milk to 0.45 for vegetable and maize meal groups and 809/a of participants were classified into adjacent quintiles. CONCLUSIONS: The QFFQ appeared to be a reproducible dietary intake assessment instrument.
OBJECTIVE: To develop and assess the reproducibility of a quantitative food frequency questionnaire (QFFQ) sensitive to the culture of the African population of the North West Province, South Africa. DESIGN: A cross-sectional study. SETTING: A community-based field study in a population stratified according to level of urbanization from deep rural to urban upper class. SUBJECTS: A total of 144 (99 women and 45 men) residents of the North West Province, aged between 15 and 65 years. participated in the study. METHODS: A culture-sensitive. 145-item interviewer-administered QFFQ was designed to cover the whole diet. Portion sizes were estimated from a food portion photograph book (FPPB) showing foods in three portion sizes. The QFFQ was administered twice, 6-12 weeks apart. RESULTS: Spearman rank correlation coefficients between the two administrations varied from 0.14 for calcium to 0.75 for alcohol. The mean percentage difference between intakes was 8.5 (standard deviation= 9.9). Energy. protein, carbohydrate and calcium gave differences within 10%. Few significant differences among correlation coefficients or percentage difference for gender, age group or strata of urbanization were present. Bland-Altman plots showed significant proportional bias for protein, fibre and vitamin C. More than 70% of the participants were classified into adjacent quintiles for all nutrients. For food groups, correlation coefficients ranged from 0.25 for milk to 0.45 for vegetable and maize meal groups and 809/a of participants were classified into adjacent quintiles. CONCLUSIONS: The QFFQ appeared to be a reproducible dietary intake assessment instrument.
Authors: Lisa Davis; Welma Stonehouse; Du Toit Loots; Janine Mukuddem-Petersen; Francois H van der Westhuizen; Susanna M Hanekom; Johann C Jerling Journal: Eur J Nutr Date: 2007-03-21 Impact factor: 5.614