Telephone surveys as a method for obtaining dietary information: a review.

The use of telephone surveys has increased significantly in the past decade. One advantage of telephone surveys is the ability to reach a large number of individuals: 97% of the US population owns telephones. Another advantage is cost savings: telephone surveys cost as little as one quarter to one half the amount of face-to-face surveys. Computer-assisted telephone interviewing has improved data collection, coding, and analysis. Random-digit dialing and a number of statistical advances such as weighting and stratification have significantly enhanced sample selection and research design of telephone surveys. The increasing need to collect dietary information from populations in an affordable fashion has expanded the use of telephone dietary surveys. To date, telephone dietary surveys have been used for follow-up after initial face-to-face contact has been made. The most common dietary instruments used are the 24-hour recall and the food frequency questionnaire. This review indicates that well-designed and well-administered telephone surveys are as good as, and may be better than, other methods for obtaining dietary information.