PICTURE-SORT METHOD FOR ADMINISTERING A FOOD FREQUENCY QUESTIONNAIRE TO OLDER ADULTS

Objective To assess the validity of a picture-sort approach to adminis tering the National Cancer Institute food frequency questionnaire to o lder adults. Design A picture-sort interview was conducted in each res pondent's home. After the picture sort, a 24-hour recall interview was administered on the same occasion. Five additional in-home recall int erviews were subsequently conducted at approximately 1-month intervals . Subjects/setting Forty-seven female and 49 male volunteers aged 66 t o 100 years were recruited from among Cardiovascular Health Study part icipants from Maryland and North Carolina. Main outcome measures Estim ates from the picture sort and the recall for intakes of macronutrient s, cholesterol, fiber, and selected vitamins and minerals exclusive of supplements. Statistical analyses Comparison of means estimated by th e two methods and correlation analyses were used. Correlations were ad justed under varied assumptions about the nature of the information co ntained in the six 24-hour recalls relative to respondents' usual inta kes. Results After correction for attenuation, Pearson correlation coe fficients for macronutrients ranged from .41 for protein to .74 for sa turated fat and cholesterol. For vitamins and minerals, correlations r anged from .26 for beta carotene to .62 for calcium. Applications Pict ure-sort estimates of mean nutrient intakes were comparable with estim ates based on 24-hour recalls, and correlations with reference data we re similar to those reported in the literature for conventionally admi nistered food frequency questionnaires. This dietary assessment method may, therefore, offer a way to simplify or structure responses to imp rove ease of administration and increase respondents' liking for the i nterview without loss of data quality.