Development of the Penn Healthy Diet screener with reference to adult dietary intake data from the National Health and Nutrition Examination Survey

Abstract

Background: There is a need for a feasible, user-friendly tool that can be employed to assess the overall quality of the diet in U.S.

Clinical settings: Our objectives were to develop the Penn Healthy Diet (PHD) screener, evaluate screener item correlations with Healthy Eating Index (HEI)-2015 components, and develop a simple scoring algorithm.

Methods: National Health and Nutrition Examination Survey (NHANES) 2017-18 dietary recall data in adults were used to define food examples in screener food groups based on components of the HEI-2015, Diet Approach to Stop Hypertension, and Alternative Mediterranean diet approaches. Instrument Content Validity Index (I-CVI) was used to evaluate the clarity and relevance of the screener. Patient acceptability was evaluated by completion time and response rates. NHANES 2017-18 food recall data were used to simulate responses to the screener items, which were evaluated for association with HEI-2015 components. A scoring algorithm was developed based on screener items moderately or strongly associated with HEI-2015 components. Reproducibility was tested using NHANES 2015-16 data.

Results: The screener had strong clarity (I-CVI = 0.971) and relevance for nutrition counseling (I-CVI = 0.971). Median (IQR) completion time was 4 (3-5) minutes on paper and 4 (4-8) minutes online, and 73% of patients invited online completed the survey. Based on simulated NHANES participant screener responses, 15 of the 29 screener items were moderately or strongly associated with HEI-2015 components, forming the basis of the scoring algorithm with a range of 0-63 points, where higher score indicates a healthier diet. The median (IQR) screener and HEI-2015 scores were 14.96 (11.99-18.36) and 48.96 (39.51-59.48), respectively. The simulated PHD score was highly correlated with the HEI-2015 score (Spearman rho 0.75) in NHANES 2017-18 and confirmed in NHANES 2015-16 data (Spearman rho 0.75).

Conclusions: The Penn Healthy Diet screener may be a useful tool for assessing diet quality due to its acceptable content validity, ease of administration, and ability to distinguish between servings of key food groups associated with a healthy versus unhealthy diet according to the HEI-2015. Additional research is needed to further establish the instrument's validity, and to refine a scoring algorithm.

Keywords: Adult; Food pattern; HEI-2015; Healthy diet; NHANES; Screener.