Retention Interval and Prompts: Creation and Cross-Sectional Pilot-Testing of Eight Interview Protocols to Obtain 24-Hour Dietary Recalls from Fourth-Grade Children

Abstract

BackgroundAny 24-hour dietary recall (24hDR) has a retention interval and prompts. No research has investigated their combined effect. ObjectiveEight 24hDR protocols, constructed by crossing two retention intervals (prior-24-hour recall obtained in afternoon and previous-day recall obtained in morning) with four prompts (forward [distant-to-recent], reverse [recent-to-distant], meal-name [eg, breakfast, lunch, etc], and open [no instructions]), were pilot-tested. DesignVia a cross-sectional design, children were interviewed once, using one of eight 24hDR protocols. Participants/settingForty-eight fourth-grade children (79% black; 50% girls; six per protocol) were randomly selected from two schools during spring 2011. Protocol assignment was random. Analyses excluded one interview due to protocol deviation. Statistical analyses performedMultivariate analysis of variance (MANOVA) with four nonaccuracy-related response variables was conducted, with independent variables retention interval, prompt, and their interaction. The significance level was 0.10 due to the study’s exploratory nature. ResultsThe response variable set differed across retention intervals (P=0.0003) and prompts (P=0.045) but not their interaction (P=0.11). Follow-up analysis of variance for each of four variables showed differences by retention interval for three and prompt for two: Interview length (minutes) differed by retention interval (prior-24-hour-afternoon=21.8, previous-day-morning=16.1; P<0.0008) and prompt (open=20.3, reverse=20.0, forward=19.1, and meal-name=16.3; P=0.079). Number of school meals reported eaten during the target period did not depend on retention interval or prompt, but was greater using meal-name prompts (1.7) than the other three prompts (1.3; P=0.055; contrast t test). Number of 10 possible meal components reported eaten at school meals differed by retention interval (prior-24-hour-afternoon=4.1, previous-day-morning=2.9; P=0.048). Weighted number of items (condiment=0.33, combination entrée=2.0, and else=1.0) reported eaten at school meals differed by retention interval (prior-24-hour-afternoon=5.8, previous-day-morning=4.1; P=0.079) and prompt (forward=6.2, meal-name=5.3, reverse=4.9, and open=3.3; P=0.093). ConclusionsChildren’s nonaccuracy-related responses to eight 24hDR protocols varied as hypothesized. The selected protocols will be useful in a planned validation study to investigate differences by protocol in children’s recall accuracy.