Agreement in alcohol consumption levels as measured by two different questionnaires

Area of Science:

• Epidemiology
• Nutritional Science
• Biostatistics

Background:

• Accurate assessment of alcohol consumption is crucial for epidemiologic studies, particularly in breast cancer research.
• Dietary assessment tools, such as food frequency questionnaires (FFQs), are commonly used but may have limitations.
• Risk factor questionnaires (RFQs) are developed for specific study designs and require validation.

Purpose of the Study:

• To evaluate the agreement between a standard food frequency questionnaire (FFQ) and a risk factor questionnaire (RFQ) for reported alcohol consumption.
• To determine the validity of alcohol intake data collected via an RFQ in the context of a genetic epidemiologic study of breast cancer.

Main Methods:

• A total of 765 subjects completed both a standard FFQ and an RFQ at home.
• The FFQ used categorical responses for alcohol intake levels.
• The RFQ employed open-ended questions to assess alcohol consumption over various time periods.

Main Results:

• Mean daily alcohol consumption was higher when reported via FFQ (7.0 g/day) compared to RFQ (5.3 g/day).
• The RFQ tended to overestimate the number of non-drinkers relative to the FFQ.
• Spearman correlation coefficients indicated relatively high agreement for total alcohol (r=0.72), beer (r=0.69), and wine (r=0.69), with moderate agreement for distilled spirits (r=0.54).

Conclusions:

• The observed agreement between the FFQ and RFQ supports the validity of historical alcohol consumption data collected using the RFQ.
• The RFQ can be a useful tool for assessing alcohol intake in genetic epidemiologic studies.
• Further research may explore specific factors contributing to differences in reported consumption levels.