Evaluation of a computerized food frequency questionnaire to estimate calcium intake of Asian, Hispanic, and non-Hispanic white youth.

The objective of this study was to evaluate a computerized food frequency questionnaire (FFQ) that estimates calcium intake among Asian, Hispanic, and non-Hispanic white youth. A computerized FFQ based on a list of 80 foods with corresponding food photos was evaluated for 4 consecutive weeks. The evaluation study consisted of computerized FFQs during weeks 1 and 4, and 24-hour dietary recalls during each of weeks 2 and 3. Subjects were a convenience sample of Asian (29%), Hispanic (36%), and non-Hispanic white (35%) youth, age 11 to 18 years, living in northern Utah (N=161). Paired t tests, percent agreement, Pearson correlation coefficients of transformed calcium intake values (using ladder of transformation), deattenuated Pearson correlation coefficients, and Spearman correlation coefficients were used to evaluate the computerized FFQ. The correlation of calcium intakes estimated by the first and second computerized FFQ, 1 month apart, was 0.72 (transformed Pearson's r) for the total sample (N=161). Correlations within subgroups were: for males, r=0.59; females, r=0.81; 11- to 14-year-olds, r=0.66; 15- to 18-year-olds, r=0.82; Asians, r=0.73; Hispanics, r=0.76; and non-Hispanic whites, r=0.61. The correlation of calcium intakes estimated by the second computerized FFQ and the mean of two 24-hour dietary recalls was 0.56 (deattenuated, transformed Pearson's r) for the total sample. Correlations were also significant for males (r=0.50), females (r=0.57), 11- to 14-year-olds (r=0.56), 15- to 18-year-olds (r=0.59), Asians (r=0.63), Hispanics (r=0.55), and non-Hispanic whites (r=0.57). This computerized FFQ was found to be reliable in estimating calcium intake among a multiethnic youth population in the United States.