Frequent food questionnaires (FFQ) are a simple way to obtain information on the foods individuals consume by asking them questions about typical amounts of food consumed in a day, a week, or a month. A more accurate picture is obtained by obtaining a detailed food diary (DR) for several days that are randomly chosen over a certain time period. The data obtained from a frequent food questionnaire can be compared with the food diary to assess the validity of the questionnaire. The correlation between alcohol consumption from the food questionnaire and diary was r = 0.89, based on seven individuals: Based on the seven individuals for whom data are available, which of the following statements is incorrect?
A)Typical consumption, as stated on the FFQ, is positively associated with what is actually consumed.
B)The FFQ is a reasonable tool to obtain information on the amount of alcohol consumed by individuals.
C)Because r 0, the amount that is truly consumed is always larger than what is stated on the FFQ.
D)All of the answer options are correct.

Question

Frequent food questionnaires (FFQ) are a simple way to obtain information on the foods individuals consume by asking them questions about typical amounts of food consumed in a day, a week, or a month. A more accurate picture is obtained by obtaining a detailed food diary (DR) for several days that are randomly chosen over a certain time period. The data obtained from a frequent food questionnaire can be compared with the food diary to assess the validity of the questionnaire. The correlation between alcohol consumption from the food questionnaire and diary was r = 0.89, based on seven individuals:  Based on the seven individuals for whom data are available, which of the following statements is incorrect?
A)Typical consumption, as stated on the FFQ, is positively associated with what is actually consumed. 
B)The FFQ is a reasonable tool to obtain information on the amount of alcohol consumed by individuals. 
C)Because r > 0, the amount that is truly consumed is always larger than what is stated on the FFQ. 
D)All of the answer options are correct.

Quizplus · Accepted Answer

This statement is incorrect because a positive correlation coefficient (r) does not necessarily mean that the true amount consumed is always larger than what is stated on the FFQ. It only indicates that there is a strong relationship between the two measures. It is possible that individuals may under-report or over-report their alcohol consumption on the FFQ, and the correlation coefficient alone does not provide information about the direction or magnitude of these reporting biases.

Frequent Food Questionnaires (FFQ) Are a Simple Way to Obtain