Validity of Telephone versus Face-to-Face Interviews in the Assessment of Bread Consumption Pattern

There are different methods to assess dietary intake in the community. Accurate and appropriate methods، rather than costly and time-consuming ones، are good alternatives to assess dietary intake. The aim of this study was to analyze the validity of telephone and face-to-face interviews، in determination of bread-consumption pattern. A randomized and stratified multi-stage sampling method was used to select 2312 participating households within the Tehran metropolitan area. The study (research) was carried out in two individual and household levels، using 24 hours recall and purchase frequency questionnaire. The same 24 hour recall and purchase frequency questionnaires were used at both individual and household level. At household and individual level، the correlation coefficients between the two methods were 0. 64 and 0. 60، respectively (p<0. 001). Mean difference of intake of bread between the methods at individual level was 16-21 g/day and at household level was 3-4 g/person/day، statistically not significant. Our findings suggest that a telephone survey can provide a reliable estimation of actual bread intake at both individual and household level. This method is important considering its cost and needed time.