Brief Diet Screener for Assessing Adherence to the Dietary Approaches to Stop Hypertension (DASH) Diet: Development...

Although poor diet quality is a main risk factor for cardiovascular disease, it is rarely measured comprehensively in clinical trials using full dietary assessment tools.

This study developed a Dietary Approaches to Stop Hypertension (DASH) diet screener using questions from the Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis trial (SAMMPRIS) and assessed construct validity in 3 2-y cycles of the National Health and Nutrition Examination Survey (2009-2014).

Two DASH scores were created in a subset of 14,651 adults aged ≥20 with ≥1 reliable 24-h diet recall and plausible energy intakes. The validated DASH score used established methods to create a score ranging from 8 to 40. The DASH screener used 11 nonvalidated SAMMPRIS questions to create 8 components. Each component was multiplied by a weight for comparability between the scores and summed to obtain an overall score (0-100), with higher values indicating better adherence. Construct validity was examined by analyzing whether the screener score had a variable distribution, correlated with the validated score, differentiated groups with known diet quality differences, and was concordant with the validated score.

Participants were on average 47.6 (±16.9) y, 68% non-Hispanic White, 53% female, and with a body mass index (BMI) of 28.9 kg/m². The mean (SD) of the DASH screener score and validated DASH score were 47.0 (14.7) and 23.8 (5.2). The elements of construct validity were demonstrated with strong correlations between the total and most components' scores (r = 0.62-1.00, P < 0.0001), the ability to distinguish known-group differences, and strong concordance between the 2 scores (κ = 0.62, P< 0.0001). In sensitivity analyses, removal of the sodium component improved the total score correlation (r = 0.73) and concordance (κ = 0.64).

The brief DASH diet screener demonstrated construct validity across 4 domains. Future research is needed to better estimate salt intake and evaluate the predictive validity of the screener.