70 [high fat diet]) was negligible (kappa statistic = 0.036). The MF was accurate at the extremes of fat intake, but could not reliably identify the 3 AHA dietary classifications. Alternative MF cutpoints of <30 (Step 2), 30–50 (Step 1), and >50 (high fat diet) were highly sensitive (96%), but had low specificity (46%) for a high fat diet. ROC curve analysis identified that a MF score cutoff of 38 provided optimal sensitivity 75% and specificity 72%, and had modest agreement (kappa = 0.39, P < 0.001) with the FFQ for the identification of subjects with a high fat diet. Conclusions The MEDFICTS questionnaire is most suitable as a tool to identify high fat diets, rather than discriminate AHA Step 1 and Step 2 diets. Currently recommended MEDFICTS cutpoints are too high, leading to overestimation of dietary quality. A cutpoint of 38 appears to be providing optimal identification of patients who do not meet AHA dietary guidelines for fat intake."/>
MEDFICTS Diet Groups | AHA Diet Steps | |||
---|---|---|---|---|
High Fat | Step 1 | Step 2 | Total | |
High Fat Diet | 29 (100.0%)* (23.2%)** | 29 (100.0%) (17.7%) | ||
Step 1 Diet | 62 (87.3%) (49.6%) | 5 (7.0%) (19.2%) | 4 (5.6%) (30.8%) | 71 (100.0%) (43.3%) |
Step 2 Diet | 34 (53.1%) (27.2%) | 21 (32.8%) (80.8%) | 9 (14.1%) (69.2%) | 64 (100.0%) (39.0%) |
Total | 125 (76.2%) (100.0%) | 26 (15.9%) (100.0%) | 13 (7.9%) (100.0%) | 164 (100.0%) (100.0%) |