Poster Topical Area: Nutritional Epidemiology
Location: Hall D
Poster Board Number: 786
Objectives: To develop and validate a short self-administered questionnaire to screen individuals with low diet quality based on the Alternative Healthy Eating Index (AHEI).
Methods: A total of 1643 adults (aged 44.6 ±14.4 y) completed a validated web-based food frequency questionnaire (webFFQ) and had their height and weight measured. A subsample of 940 individuals also provided a blood sample and had their body composition and blood pressure measured. The AHEI, a score predictive of chronic disease risk, calculated from the webFFQ data was used to arbitrarily classify the quality of diet as adequate (AHEI score ≥65/110) or inadequate (AHEI score <65/110). The screener was built using a classification and regression tree (CART) approach based on individual answers to the 150 questions of the webFFQ among individuals considered to have plausible energy intake (ratio of reported energy intake to basal metabolic rate ≥1.2 and <2.4; n=1040). A second cohort of 3345 adults (aged 66.5 ±6.4 y) was used to validate the predictive values of the diet quality screener in an older population.
Results: The decision tree yielded by the CART approach included sequences of 3 to 6 binary questions, leading to 21 different pathways. In the development sample, the area under the Receiver Operating Characteristic (ROC) curve was 0.92, with sensitivity, specificity and agreement values of 89.5%, 83.9% and 87.2%. Compared to individuals classified as having inadequate diet, individuals classified as having adequate diet were significantly older, had lower BMI, percent body fat and waist circumference (all P<0.001), and had lower blood pressure, triglycerides, cholesterol/HDL ratio and fasting insulin as well as higher HDL-cholesterol concentrations (all P<0.05) in both men and women. Similar results were observed in the validation sample, although overall performance of the screener for diet quality was slightly lower than among younger individuals, with an area under the ROC of 0.79 and sensitivity, specificity and agreement values of 73.0%, 69.0% and 71.3%.
Conclusion: The CART approach yielded a simple and rapid screener that identifies individuals at risk of having diet of poor nutritional quality. Further studies will be undertaken to test performance of the screener in a in a primary care setting.
Funding Source: None
Quebec, Quebec, Canada