Abstract 2372: Validity of the MEDFICTS Dietary Assessment Questionnaire in a Diverse Population
Background: The National Cholesterol Education Program (NCEP) recommends MEDFICTS, a rapid dietary fat screening instrument, for assessment of adherence to the Adult Treatment Panel (ATP) III Therapeutic Lifestyle Change (TLC) diet (Score < 40 points = < 7% of calories from saturated fat, <30% of calories from total fat, and <200mg dietary cholesterol/day). MEDFICTS has only been validated in small, select populations and its utility in diverse clinical settings is unknown. The purpose of this study was to evaluate the ability of MEDFICTS to identify individuals non-adherent to a TLC diet against a gold standard in an ethnically diverse population.
Methods: MEDFICTS was administered concurrently with the Gladys Block Food Frequency Questionnaire to participants (n=470; 35% non-white; 66% female; mean age 48.1 ± 13.6y) in the NHLBI Family Intervention Trial for Heart Health (F.I.T. Heart) at the baseline screening visit. Correlation, agreement, sensitivity and specificity analyses were conducted overall and by sex, age, and race/ethnicity.
Results: MEDFICTS score correlated significantly with % calories from saturated fat (r=.51, p<.0001), % calories from total fat (r=.30, p<.0001), and mg/day dietary cholesterol (r=.53, p=<.0001). Categorical agreement between MEDFICTS score <40 and Gladys Block on TLC diet adherence was poor overall (κ = 0.07) and for individual TLC components:
<7% calories from saturated fat (κ=.12),
<30% calories from total fat (κ=.16),
<200mg dietary cholesterol per day (κ=.34).
Sensitivity of MEDFICTS to correctly identify TLC diet adherence was 84% and did not differ significantly by sex, age, or race/ethnicity. Specificity of MEDFICTS to correctly identify non-adherence to TLC diet was low (57%) and was significantly worse for females than males (48% vs. 74%; p<.0001), but did not differ significantly in older vs. younger participants or among whites and non-whites.
Conclusion: The NCEP ATP III MEDFICTS dietary assessment questionnaire performed poorly as a screening tool to correctly identify patients non-adherent to a TLC diet. Our data suggest a re-calibration of the instrument to improve specificity may increase its clinical utility.