Fourth-Grade Children's Dietary Recall Accuracy Is Influenced by Retention Interval (Target Period and Interview Time)

Abstract

BackgroundFor a 24-hour dietary recall, two possible target periods are the prior 24 hours (24 hours immediately preceding the interview time) and previous day (midnight to midnight of the day before the interview), and three possible interview times are morning, afternoon, and evening. Target period and interview time determine the retention interval (elapsed time between to-be-reported meals and the interview), which, along with intervening meals, can influence reporting accuracy. ObjectiveThe effects of target period and interview time on children's accuracy for reporting school meals during 24-hour dietary recalls were investigated. Design and subjects/settingDuring the 2004-2005, 2005-2006, and 2006-2007 school years in Columbia, SC, each of 374 randomly selected fourth-grade children (96% African American) was observed eating two consecutive school meals (breakfast and lunch) and interviewed to obtain a 24-hour dietary recall using one of six conditions defined by crossing two target periods with three interview times. Each condition had 62 or 64 children (half boys). Main outcome measuresAccuracy for reporting school meals was quantified by calculating rates for omissions (food items observed eaten but unreported) and intrusions (food items reported eaten but unobserved); a measure of total inaccuracy combined errors for reporting food items and amounts. Statistical analyses performedFor each accuracy measure, analysis of variance was conducted with target period, interview time, their interaction, sex, interviewer, and school year in the model. ResultsThere was a target-period effect and a target-period by interview-time interaction on omission rates, intrusion rates, and total inaccuracy (six P values <0.004). For prior-24-hour recalls compared to previous-day recalls, and for prior-24-hour recalls in the afternoon and evening compared to previous-day recalls in the afternoon and evening, omission rates were better by one third, intrusion rates were better by one half, and total inaccuracy was better by one third. ConclusionsTo enhance children's dietary recall accuracy, target periods and interview times that minimize the retention interval should be chosen.