PURPOSE: Previous work has established that the Heart Fit Rx Diet Habits Survey (HFD), formerly the Food Frequency Assessment Tool, compares favorably (r = 0.78; P <.01) with the Oregon Health Sciences University Diet Habit Survey. The purpose of this study was to assess the validity and reliability of the HFD in estimating fat intake as a percentage of calories. METHODS: The validity study assessed 137 patients undergoing cardiac rehabilitation (age, 60.7 +/- 11.3 years) who completed the HFD (29 questions, 11 of which were dietary fat related [fat subscore]) and a 3-day food record. A regression equation was obtained using HFD subscores to estimate fat intake as a percentage of calories. The regression equation was tested using 50 patients not included in the original cohort. Reliability was assessed using a third group of 31 patients in a 4-week test-retest analysis. RESULTS: The correlation coefficient between the 3-day record and the HFD fat subscore was 0.65 (P <.01). The correlation coefficient for women (r = 0.77) was slightly higher than for men (r = 0.62). The regression equation derived from the HFD fat subscore was as follows: percentage of dietary fat = 50.65 - 0.736 (HFD fat subscore). The correlation coefficient for actual and predicted values was 0.58 (P <.01). Differences between estimated fat intake, as determined by the 3-day record and the HFD, ranged from 0% to 25% and were within 5% for 26 of the 50 subjects (52%), and within 10% for 41 of the 50 subjects (82%). The mean difference between the two measures was 1.5% (P =.17). Test-retest reliability was high for both the HFD total score (r = 0.95) and the HFD fat subscore (r = 0.85; P <.01). CONCLUSIONS: The HFD is an inexpensive, valid, and reliable clinical instrument for assessing dietary fat. It can be a viable alternative to other time-consuming methods, including computerized analysis.
PURPOSE: Previous work has established that the Heart Fit Rx Diet Habits Survey (HFD), formerly the Food Frequency Assessment Tool, compares favorably (r = 0.78; P <.01) with the Oregon Health Sciences University Diet Habit Survey. The purpose of this study was to assess the validity and reliability of the HFD in estimating fat intake as a percentage of calories. METHODS: The validity study assessed 137 patients undergoing cardiac rehabilitation (age, 60.7 +/- 11.3 years) who completed the HFD (29 questions, 11 of which were dietary fat related [fat subscore]) and a 3-day food record. A regression equation was obtained using HFD subscores to estimate fat intake as a percentage of calories. The regression equation was tested using 50 patients not included in the original cohort. Reliability was assessed using a third group of 31 patients in a 4-week test-retest analysis. RESULTS: The correlation coefficient between the 3-day record and the HFD fat subscore was 0.65 (P <.01). The correlation coefficient for women (r = 0.77) was slightly higher than for men (r = 0.62). The regression equation derived from the HFD fat subscore was as follows: percentage of dietary fat = 50.65 - 0.736 (HFD fat subscore). The correlation coefficient for actual and predicted values was 0.58 (P <.01). Differences between estimated fat intake, as determined by the 3-day record and the HFD, ranged from 0% to 25% and were within 5% for 26 of the 50 subjects (52%), and within 10% for 41 of the 50 subjects (82%). The mean difference between the two measures was 1.5% (P =.17). Test-retest reliability was high for both the HFD total score (r = 0.95) and the HFD fat subscore (r = 0.85; P <.01). CONCLUSIONS: The HFD is an inexpensive, valid, and reliable clinical instrument for assessing dietary fat. It can be a viable alternative to other time-consuming methods, including computerized analysis.