Variations in sensitivity, specificity, and predictive value of a dietary fat screener modified from Block et al

J Am Diet Assoc. 1995 May;95(5):564-8. doi: 10.1016/S0002-8223(95)00153-0.


Objective: To evaluate the ability of a fat screener modified from Block et al to discriminate persons whose diets consist of 38% of kilocalories or more from fat from the remainder of the population.

Design: Sensitivity, specificity, and positive predictive value of the adapted screener were calculated. Percentage of kilocalories from fat was assessed by means of a semi-quantitative food frequency questionnaire. Three cutoff points from the fat screener were used to examine which best identified those whose diets consisted of 38% of kilocalories or more from fat.

Subjects: Nine hundred ninety-seven persons responded to a food frequency questionnaire sent to a random sample of 2,000 members of a health maintenance organization.

Results: Sensitivity and specificity varied depending on which cutoff point from the fat screener was used. Sensitivity reached a high of 83.3% and specificity reached a high of 92.1%, but the screener was never highly sensitive and specific simultaneously, and the results did not vary considerably by race. The screener had low rates of gross misclassification into quintiles (< or = 2.7%) and was more effective at classifying respondents into quintiles of total fat intake (64.9% to 85.5% classified in the same quintile) than into quintiles of percentage of kilocalories from fat (43.2% to 60.5% classified in the same quintile).

Conclusions: The adapted fat screener may be used in conjunction with other dietary evaluation methods, but it exhibits insufficient sensitivity and specificity to be used as a single assessment method.

MeSH terms

  • Adult
  • African Americans
  • Diet Records*
  • Dietary Fats / administration & dosage*
  • Eating*
  • Energy Intake
  • European Continental Ancestry Group
  • Female
  • Humans
  • Male
  • Mass Screening / standards*
  • Middle Aged
  • Odds Ratio
  • Sensitivity and Specificity
  • Sex Factors
  • Surveys and Questionnaires


  • Dietary Fats