Quality control for interviews to obtain dietary recalls from children for research studies

Fourth-grade children's dietary reporting accuracy by meal component: Results from a validation study that manipulated retention interval and prompts

We examined reporting accuracy by meal component (beverage, bread, breakfast meat, combination entrée, condiment, dessert, entrée, fruit, vegetable) with validation-study data on 455 fourth-grade children (mean age = 9.92 ± 0.41 years) observed eating school meals and randomized to one of eight dietary recall conditions (two retention intervals [short, long] crossed with four prompts [forward, meal-name, open, reverse]). Accuracy category (match [observed and reported], omission [observed but unreported], intrusion [unobserved but reported]) was a polytomous nominal item response variable. We fit a multilevel cumulative logit model with item variables meal component and serving period (breakfast, lunch) and child variables retention interval, prompt and sex. Significant accuracy category predictors were meal component (p < 0.0003), retention interval (p < 0.0003), meal-component × serving-period (p < 0.0003) and meal-component × retention-interval (p = 0.001). The relationship of meal component and accuracy category was much stronger for lunch than breakfast. For lunch, beverages were matches more often, omissions much less often and intrusions more often than expected under independence; fruits and desserts were omissions more often. For the meal-component × retention-interval interaction, for the short retention interval, beverages were intrusions much more often but combination entrées and condiments were intrusions less often; for the long retention interval, beverages were matches more often and omissions less often but fruits were matches less often. Accuracy for each meal component appeared better with the short than long retention interval. For lunch and for the short retention interval, children's reporting was most accurate for entrée and combination entrée meal components, whereas it was least accurate for vegetable and fruit meal components. Results have implications for conclusions of studies and interventions assessed with dietary recalls obtained from children.

Fourth-Grade Children's Reporting Accuracy for Amounts Eaten at School-Provided Meals: Insight from a Reporting-Error-Sensitive Analytic Approach Applied to Validation Study Data

BACKGROUND

Validation studies that have directly assessed reporting accuracy for amounts eaten have provided results in various ways.

OBJECTIVE

To analyze amount categories of a reporting-error-sensitive approach for insight concerning reporting accuracy for amounts eaten.

DESIGN

For a cross-sectional validation study, children were observed eating school-provided breakfast and lunch, and randomized to one of eight 24-hour recall conditions (two retention intervals [short and long] crossed with four prompts [forward, meal name, open, and reverse]).

PARTICIPANTS/SETTING

Data collected during 3 school years (2011-2012 to 2013-2014) on 455 children from 10 schools (four districts) in a southern US state.

MAIN OUTCOME MEASURES

Items were classified as matches (observed and reported), omissions (observed but unreported), or intrusions (unobserved but reported). Within amount categories (matches [corresponding, overreported, and underreported], intrusions [overreported], and omissions [underreported]), item amounts were converted to kilocalories.

STATISTICAL ANALYSES PERFORMED

A multilevel model was fit with food-level explanatory variables (amount category and meal) and child-level explanatory variables (retention interval, prompt, sex, and race/ethnicity). To investigate inaccuracy differences, t tests on three contrasts were performed.

RESULTS

Inaccuracy differed by amount category (P<0.001; in order from largest to smallest: omission, intrusion, underreported match, and overreported match), meal (P=0.01; larger for breakfast), retention interval (P=0.003; larger for long), sex (P=0.004; larger for boys), race/ethnicity (P=0.045; largest for non-Hispanic whites), and amount category×meal interaction (P=0.046). Overreported amounts were larger for intrusions than overreported matches (P<0.0001). Underreported amounts were larger for omissions than underreported matches (P<0.0001). Overall underreported amounts (from omissions and underreported matches) exceeded overall overreported amounts (from intrusions and overreported matches) (P<0.003).

CONCLUSIONS

Amount categories provide a standard way to analyze validation study data on reporting accuracy for amounts eaten, and compare results across studies. Multilevel analytic models reflecting the data structure are recommended for inference. To enhance reporting accuracy for amounts eaten, focus on increasing reports of correct items, thereby yielding more matches with fewer intrusions and omissions.

Children's school-breakfast reports and school-lunch reports (in 24-h dietary recalls): conventional and reporting-error-sensitive measures show inconsistent accuracy results for retention interval and breakfast location

Validation-study data were analysed to investigate retention interval (RI) and prompt effects on the accuracy of fourth-grade children's reports of school-breakfast and school-lunch (in 24-h recalls), and the accuracy of school-breakfast reports by breakfast location (classroom; cafeteria). Randomly selected fourth-grade children at ten schools in four districts were observed eating school-provided breakfast and lunch, and were interviewed under one of eight conditions created by crossing two RIs ('short'--prior-24-hour recall obtained in the afternoon and 'long'--previous-day recall obtained in the morning) with four prompts ('forward'--distant to recent, 'meal name'--breakfast, etc., 'open'--no instructions, and 'reverse'--recent to distant). Each condition had sixty children (half were girls). Of 480 children, 355 and 409 reported meals satisfying criteria for reports of school-breakfast and school-lunch, respectively. For breakfast and lunch separately, a conventional measure--report rate--and reporting-error-sensitive measures--correspondence rate and inflation ratio--were calculated for energy per meal-reporting child. Correspondence rate and inflation ratio--but not report rate--showed better accuracy for school-breakfast and school-lunch reports with the short RI than with the long RI; this pattern was not found for some prompts for each sex. Correspondence rate and inflation ratio showed better school-breakfast report accuracy for the classroom than for cafeteria location for each prompt, but report rate showed the opposite. For each RI, correspondence rate and inflation ratio showed better accuracy for lunch than for breakfast, but report rate showed the opposite. When choosing RI and prompts for recalls, researchers and practitioners should select a short RI to maximise accuracy. Recommendations for prompt selections are less clear. As report rates distort validation-study accuracy conclusions, reporting-error-sensitive measures are recommended.

Effectiveness of Prompts on Fourth-Grade Children's Dietary Recall Accuracy Depends on Retention Interval and Varies by Gender

BACKGROUND

Dietary recall accuracy is related to retention interval (RI) (i.e., time between to-be-reported meals and the interview), and possibly to prompts. To the best of our knowledge, no study has evaluated their combined effect.

OBJECTIVE

The combined influence of RI and prompts on children's recall accuracy was investigated in this study. Two RIs [short (prior-24-h recall obtained in afternoon) and long (previous-day recall obtained in morning)] were crossed with 4 prompts [forward (distant-to-recent), meal-name (breakfast, lunch, etc.), open (no instructions), and reverse (recent-to-distant)], creating 8 conditions.

METHODS

Fourth-grade children (n = 480; 50% girls) were randomly selected from consenting children at 10 schools in 4 districts in a southern state during 3 school years (2011-2012, 2012-2013, and 2013-2014). Each child was observed eating school-provided breakfast and lunch, and interviewed one time under 1 of the 8 conditions. Condition assignment was constrained so that each had 60 children (30 girls). Accuracy measures were food-item omission and intrusion rates, and energy correspondence rate and inflation ratio. For each measure, linear models determined effects of RI, prompt, gender, and interactions (2-way, 3-way); race/ethnicity, school year, and district were control variables.

RESULTS

RI (P values < 0.015) and prompt (P values < 0.005) were significant for all 4 accuracy measures. RI × prompt (P values < 0.001) was significant for 3 accuracy measures (not intrusion rate). Prompt × gender (P = 0.005) was significant for omission rate. RI × prompt × gender was significant for intrusion rate and inflation ratio (P values < 0.001). For the short vs. long RI across prompts and genders, accuracy was better by 33-50% for each accuracy measure.

CONCLUSIONS

To obtain the most accurate recalls possible from children, studies should be designed to use a short rather than long RI. Prompts affect children's recall accuracy, although the effectiveness of different prompts depends on RI and varies by gender: at a short RI, the choice of prompts has little systematic effect on accuracy, whereas at a long RI, reverse prompts may elicit the most accurate recalls.

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

BACKGROUND

Any 24-hour dietary recall (24hDR) has a retention interval and prompts. No research has investigated their combined effect.

OBJECTIVE

Eight 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.

DESIGN

Via a cross-sectional design, children were interviewed once, using one of eight 24hDR protocols.

PARTICIPANTS/SETTING

Forty-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 PERFORMED

Multivariate 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.

RESULTS

The 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).

CONCLUSIONS

Children'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.

A validation study concerning the effects of interview content, retention interval, and grade on children's recall accuracy for dietary intake and/or physical activity

BACKGROUND

Practitioners and researchers are interested in assessing children's dietary intake and physical activity together to maximize resources and minimize subject burden.

OBJECTIVE

Our aim was to investigate differences in dietary and/or physical activity recall accuracy by content (diet only; physical activity only; diet and physical activity), retention interval (same-day recalls in the afternoon; previous-day recalls in the morning), and grade (third; fifth).

DESIGN

Children (n=144; 66% African American, 13% white, 12% Hispanic, 9% other; 50% girls) from four schools were randomly selected for interviews about one of three contents. Each content group was equally divided by retention interval, each equally divided by grade, each equally divided by sex. Information concerning diet and physical activity at school was validated with school-provided breakfast and lunch observations, and accelerometry, respectively. Dietary accuracy measures were food-item omission and intrusion rates, and kilocalorie correspondence rate and inflation ratio. Physical activity accuracy measures were absolute and arithmetic differences for moderate to vigorous physical activity minutes.

STATISTICAL ANALYSES PERFORMED

For each accuracy measure, linear models determined effects of content, retention interval, grade, and their two-way and three-way interactions; ethnicity and sex were control variables.

RESULTS

Content was significant within four interactions: intrusion rate (content×retention-interval×grade; P=0.0004), correspondence rate (content×grade; P=0.0004), inflation ratio (content×grade; P=0.0104), and arithmetic difference (content×retention-interval×grade; P=0.0070). Retention interval was significant for correspondence rate (P=0.0004), inflation ratio (P=0.0014), and three interactions: omission rate (retention-interval×grade; P=0.0095), intrusion rate, and arithmetic difference (both already mentioned). Grade was significant for absolute difference (P=0.0233) and five interactions mentioned. Content effects depended on other factors. Grade effects were mixed. Dietary accuracy was better with same-day than previous-day retention interval.

CONCLUSIONS

Results do not support integrating dietary intake and physical activity in children's recalls, but do support using shorter rather than longer retention intervals to yield more accurate dietary recalls. Additional validation studies need to clarify age effects and identify evidence-based practices to improve children's accuracy for recalling dietary intake and/or physical activity.

Shortening the retention interval of 24-hour dietary recalls increases fourth-grade children's accuracy for reporting energy and macronutrient intake at school meals

BACKGROUND

Accurate information about children's intake is crucial for national nutrition policy and for research and clinical activities. To analyze accuracy for reporting energy and nutrients, most validation studies utilize the "conventional approach," which was not designed to capture errors of reported foods and amounts. The "reporting-error-sensitive approach" captures errors of reported foods and amounts.

OBJECTIVE

To extend results to energy and macronutrients for a validation study concerning retention interval (elapsed time between to-be-reported meals and the interview) and accuracy for reporting school-meal intake, the conventional and reporting-error-sensitive approaches were compared. DESIGN AND PARTICIPANTS/SETTING: Fourth-grade children (n=374) were observed eating two school meals, and interviewed to obtain a 24-hour recall using one of six interview conditions from crossing two target periods (prior 24 hours and previous day) with three interview times (morning, afternoon, and evening). Data were collected in one district during three school years (2004-2005, 2005-2006, and 2006-2007).

MAIN OUTCOME MEASURES

Report rates (reported/observed), correspondence rates (correctly reported/observed), and inflation ratios (intruded/observed) were calculated for energy and macronutrients.

STATISTICAL ANALYSES PERFORMED

For each outcome measure, mixed-model analysis of variance was conducted with target period, interview time, their interaction, and sex in the model; results were adjusted for school year and interviewer.

RESULTS

With the conventional approach, report rates for energy and macronutrients did not differ by target period, interview time, their interaction, or sex. With the reporting-error-sensitive approach, correspondence rates for energy and macronutrients differed by target period (four P values <0.0001) and the target period by interview-time interaction (four P values <0.0001); inflation ratios for energy and macronutrients differed by target period (four P values <0.0001), and inflation ratios for energy and carbohydrate differed by the target period by interview-time interaction (both P values <0.005).

CONCLUSIONS

Shortening the retention interval of dietary recalls increases accuracy for reporting energy and macronutrients. For validation studies, it is best to obtain reference information from a method that provides details about foods and amounts consumed and to use an analytic approach that captures errors of reported foods and amounts.

Total daily water intake in Guatemalan children

BACKGROUND

Water is an essential nutrient, but recommendations for total water requirements only emerged in 2005, in the context of estimated average population targets in the Dietary Reference Intakes (DRIs) for US and Canadian societies.

OBJECTIVE

To assess total daily water acquisition, and the contribution of water acquired from all possible sources, among Guatemalan children.

METHODS

A total of 449 urban Guatemalan schoolchildren, aged 8 to 11 years, evenly divided between two socioeconomic strata, completed a 1-day pictorial registry of all foods and beverages consumed. Estimated energy intake, total water intake, and the contributions of water from drinking water, beverages, intrinsic and extrinsic water in foods, and the oxidation of macronutrients were assessed.

RESULTS

The contribution of water from the examined water sources was 8% for drinking water, 49% for beverages, 29% for all foods, and 14% for metabolism of macronutrients, with only slight variance across sexes and social class. The average total daily water acquisition was 1,841 +/- 572 mL for boys and 1,834 +/- 484 mL for girls, which fall short of the North American DRI recommendations of 2.4 and 2.1 L, respectively There was correspondingly lower average consumption of dietary liquids.

CONCLUSIONS

Foods play an important role in the acquisition of water from their hydration and metabolic oxidation, contributing 43.8% of the daily supply to these children. There is still a calculated shortfall of daily water acquisition, as compared with the DRI recommendations, which could be overcome by greater intake of plain water and low-energy fresh produce.

Accuracy of children's school-breakfast reports and school-lunch reports (in 24-h dietary recalls) differs by retention interval

BACKGROUND/OBJECTIVES

Validation-study data were analyzed to investigate the effect of retention interval (time between the to-be-reported meal and interview) on accuracy of children's school-breakfast reports and school-lunch reports in 24-h recalls, and to compare accuracy of children's school-breakfast reports for two breakfast locations (classroom; cafeteria).

SUBJECTS/METHODS

Each of 374 fourth-grade children was interviewed to obtain a 24-h recall using one of six conditions from crossing two target periods (prior 24 h; previous day) with three interview times (morning; afternoon; evening). Each condition had 62 or 64 children (half boys). A recall's target period included one school breakfast and one school lunch, for which the child had been observed. Food-item variables (observed number; reported number; omission rate; intrusion rate) and energy variables (observed; reported; report rate; correspondence rate; inflation ratio) were calculated for each child for school breakfast and school lunch separately.

RESULTS

Accuracy for school-breakfast reports and school-lunch reports was inversely related to retention interval. Specifically, as indicated by smaller omission rates, smaller intrusion rates, larger correspondence rates and smaller inflation ratios, accuracy for school-breakfast reports was best for prior-24-h recalls in the morning, and accuracy for school-lunch reports was best for prior-24-h recalls in the afternoon. For neither school meal was a significant sex effect found for any variable. For school-breakfast reports, there was no significant school-breakfast location effect for any variable.

CONCLUSIONS

By shortening the retention interval, accuracy can be improved for school-breakfast reports and school-lunch reports in children's 24-h recalls.

Fourth-grade children's dietary recall accuracy is influenced by retention interval (target period and interview time)

BACKGROUND

For 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.

OBJECTIVE

The 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/SETTING: During 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 MEASURES

Accuracy 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 PERFORMED

For each accuracy measure, analysis of variance was conducted with target period, interview time, their interaction, sex, interviewer, and school year in the model.

RESULTS

There 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.

CONCLUSIONS

To enhance children's dietary recall accuracy, target periods and interview times that minimize the retention interval should be chosen.

Cognitive processes in children's dietary recalls: insight from methodological studies

BACKGROUND/OBJECTIVES

This article summarizes 12 dietary-reporting methodological studies with children (six validation studies, one non-validation study, five secondary analyses studies of data from one or more of the six validation studies), identifies research gaps and provides recommendations for (a) improving children's recall accuracy and (b) details to specify in publications of studies that utilize children's dietary recalls.

SUBJECTS/METHODS

Randomly selected children (aged 9-10 years) were observed eating school breakfast and school lunch, and interviewed to obtain dietary recalls.

RESULTS

Children's recall accuracy improved slightly between the first and third recalls, but an individual child's accuracy was inconsistent from one interview to the next. Although accuracy was poor overall, it was better for boys with reverse-order (evening-to-morning) prompts and for girls with forward-order (morning-to-evening) prompts. Children recalled breakfast intake less accurately than lunch intake. Children's accuracy did not depend on whether recalls were obtained in person or by telephone, but was better for recalls obtained with an open format than a meal format. Retention interval was crucial as children's accuracy was better for prior-24-h recalls (about the 24 h immediately preceding the interview) than for previous-day recalls (about midnight to midnight of the day before the interview). Observations of school meals did not affect children's recalls. Children's recall accuracy was related to their age/sex body mass index percentile. Conventional report rates (which disregard accuracy for items and amounts) overestimated accuracy for energy and macronutrients, and masked complexities of recall error.

CONCLUSIONS

Research concerning errors in children's dietary recalls provides insight for improving children's recall accuracy.

Twenty-four hour dietary recalls by fourth-grade children were not influenced by observations of school meals

OBJECTIVE

To investigate whether school-meal observations influenced children's 24-hour dietary recalls.

STUDY DESIGN AND SETTING

Over three school years, 555 randomly selected fourth-grade children were interviewed to obtain a 24-hour dietary recall; before being interviewed, 374 children were observed eating two school meals (breakfast, lunch), and 181 children were not observed. Within observation-status groups (observed, unobserved), children were randomized within sex to one of six combinations from two target periods (prior 24 hours, previous day) crossed with three interview times (morning, afternoon, evening).

RESULTS

For each of the five variables (interview length, meals/snacks, meal components, items, kilocalories), naïve and adjusted equivalence tests rejected that observation-status groups were different, indicating that school-meal observations did not influence children's 24-hour dietary recalls. There was a target-period effect on length (P<0.0001) (longer for prior-24-hour recalls), a school year effect on length (P=0.0002) (longer for third year), and a target period-interview time interaction on items (P=0.0110) and kilocalories (P=0.0047) (both smaller for previous-day recalls in the afternoon than prior-24-hour recalls in the afternoon and previous-day recalls in the evening), indicating that variables were sufficiently sensitive and psychometrically reliable.

CONCLUSION

Conclusions about 24-hour dietary recalls by fourth-grade children observed eating school meals in validation studies are generalizable to 24-hour dietary recalls by comparable but unobserved children in nonvalidation studies.

Children's Dietary Recalls from Three Validation Studies: Types of Intrusion Vary with Retention Interval

Using previously collected data of fourth-grade children observed eating school meals and then interviewed, we categorized intrusions (food items reported but not observed eaten) as stretches (on the child's tray) or confabulations (not on the child's tray). We investigated intrusions, confabulations, and stretches, and the role of liking, at different retention intervals (morning interviews about the previous day's intake; evening interviews about that day's intake) and under different reporting-order prompts (forward; reverse). As retention interval between consumption and report increased, the likelihood 1) increased that reported items were intrusions, that reported items were confabulations, and that intrusions were confabulations; and 2) was constant that reported items were stretches. Results concerning reporting-order prompts were inconclusive. Liking ratings were higher for matches (reports of items observed eaten) than stretches, for confabulations than stretches, and for matches than omissions (unreported items observed eaten), but did not vary by retention interval or reporting-order prompts.

Origins of intrusions in children's dietary recalls: data from a validation study concerning retention interval and information from school food-service production records

OBJECTIVE

To use data from a published validation study concerning retention interval and school food-service production records to examine intrusions (uneaten items reported eaten) in the school-meal parts of 24 h recalls.

DESIGN

For that study, children were observed eating two school meals (breakfast, lunch) and interviewed under one of six conditions from two target periods (previous day (PDTP), prior 24 h (24TP)) crossed with three interview times (morning, afternoon (AIT), evening). For the present article, a catalogue was constructed of foods available for that study's school meals. The study's intrusions were classified as stretches (on children's meal trays but uneaten), internal confabulations (in children's school food-service environments for that meal but not on children's trays) or external confabulations (not in children's school food-service environments for that meal). Occurrence, types and amounts of intrusions were investigated.

SETTING/SUBJECTS

Six schools; sixty fourth-grade children (ten per condition).

RESULTS

For breakfast, for the 24TP v. PDTP, reported items were less likely to be intrusions, internal confabulations and external confabulations; and intrusions were more likely to be stretches. For lunch, for the 24TP-AIT condition v. the other five conditions, reported items were less likely to be intrusions and external confabulations. Mean amounts reported eaten were smaller for stretches than for internal confabulations or external confabulations at breakfast, and for stretches than for internal confabulations at lunch.

CONCLUSIONS

Accuracy was better for the 24TP (with fewer intrusions of which proportionally more were stretches which had smaller amounts reported eaten) than for the PDTP. Studies with 24 h recalls should minimize retention interval to improve accuracy.

Children's recalls from five dietary-reporting validation studies. Intrusions in correctly reported and misreported options in school breakfast reports

For school breakfast each day, many elementary schools offer a choice between a cold option that includes ready-to-eat (RTE) cereal and a hot option that includes a non-RTE-cereal entrée such as waffles. For breakfast reports, intrusions (reports of uneaten items) in correctly reported and misreported breakfast options were examined using data from five dietary-reporting validation studies. In each study, fourth-grade children were observed eating school breakfast and school lunch and then interviewed to obtain a dietary recall. A breakfast option was correctly reported in 240 breakfast reports for 203 intrusions total, and misreported in 97 breakfast reports for 189 intrusions total. Asymmetry was evident in misreported options; specifically, children observed eating a cold option almost never misreported a hot option, but children observed eating a hot option often misreported a cold option. Proportionately more breakfast reports were intrusion-free when a breakfast option was correctly reported than misreported. Linking of intrusions (i.e., multiple intrusions from the same option in a breakfast report) was especially evident with misreported breakfast options. Methodological aspects of dietary recalls such as target period (prior 24h; previous day), interview time (morning; afternoon; evening), and interview format (meal; open) had implications for intrusions and misreported breakfast options.

Conclusions about children's reporting accuracy for energy and macronutrients over multiple interviews depend on the analytic approach for comparing reported information to reference information

OBJECTIVE

Validation study data are used to illustrate that conclusions about children's reporting accuracy for energy and macronutrients over multiple interviews (ie, time) depend on the analytic approach for comparing reported and reference information-conventional, which disregards accuracy of reported items and amounts, or reporting-error-sensitive, which classifies reported items as matches (eaten) or intrusions (not eaten), and amounts as corresponding or overreported.

SUBJECTS AND DESIGN

Children were observed eating school meals on 1 day (n=12), or 2 (n=13) or 3 (n=79) nonconsecutive days separated by >or=25 days, and interviewed in the morning after each observation day about intake the previous day. Reference (observed) and reported information were transformed to energy and macronutrients (ie, protein, carbohydrate, and fat), and compared.

MAIN OUTCOME MEASURES

For energy and each macronutrient: report rates (reported/reference), correspondence rates (genuine accuracy measures), and inflation ratios (error measures).

STATISTICAL ANALYSES

Mixed-model analyses.

RESULTS

Using the conventional approach for analyzing energy and macronutrients, report rates did not vary systematically over interviews (all four P values >0.61). Using the reporting-error-sensitive approach for analyzing energy and macronutrients, correspondence rates increased over interviews (all four P values <0.04), indicating that reporting accuracy improved over time; inflation ratios decreased, although not significantly, over interviews, also suggesting that reporting accuracy improved over time. Correspondence rates were lower than report rates, indicating that reporting accuracy was worse than implied by conventional measures.

CONCLUSIONS

When analyzed using the reporting-error-sensitive approach, children's dietary reporting accuracy for energy and macronutrients improved over time, but the conventional approach masked improvements and overestimated accuracy. The reporting-error-sensitive approach is recommended when analyzing data from validation studies of dietary reporting accuracy for energy and macronutrients.

Conventional analyses of data from dietary validation studies may misestimate reporting accuracy: illustration from a study of the effect of interview modality on children's reporting accuracy

OBJECTIVE

To compare two approaches to analysing energy- and nutrient-converted data from dietary validation (and relative validation) studies - conventional analyses, in which the accuracy of reported items is not ascertained, and reporting-error-sensitive analyses, in which reported items are classified as matches (items actually eaten) or intrusions (items not actually eaten), and reported amounts are classified as corresponding or overreported.

DESIGN

Subjects were observed eating school breakfast and lunch, and interviewed that evening about that day's intake. For conventional analyses, reference and reported information were converted to energy and macronutrients; then t-tests, correlation coefficients and report rates (reported/reference) were calculated. For reporting error-sensitive analyses, reported items were classified as matches or intrusions, reported amounts were classified as corresponding or overreported, and correspondence rates (corresponding amount/reference amount) and inflation ratios (overreported amount/reference amount) were calculated.

SUBJECTS

Sixty-nine fourth-grade children (35 girls) from 10 elementary schools in Georgia (USA).

RESULTS

For energy and each macronutrient, conventional analyses found that reported amounts were significantly less than reference amounts (every P < 0.021; paired t-tests); correlations between reported and reference amounts exceeded 0.52 (every P < 0.001); and median report rates ranged from 76% to 95%. Analyses sensitive to reporting errors found median correspondence rates between 67% and 79%, and that median inflation ratios, which ranged from 7% to 17%, differed significantly from 0 (every P < 0.0001; sign tests).

CONCLUSIONS

Conventional analyses of energy and nutrient data from dietary reporting validation (and relative validation) studies may overestimate accuracy and mask the complexity of dietary reporting error.

Validation-study conclusions from dietary reports by fourth-grade children observed eating school meals are generalisable to dietary reports by comparable children not observed

OBJECTIVE

To investigate the effect of observing school meals on children's dietary reports.

SUBJECTS AND SETTING

One hundred and twenty children randomly selected, but with half girls, from usual school-meal eaters among 312 volunteers (from all 443 fourth-grade children in six schools in one district).

DESIGN

Children were assigned randomly to one of 12 conditions yielded by crossing observation status (observed; not observed), target period (previous day; prior 24 hours), and interview time (morning; afternoon; evening).

RESULTS

Response variables included interview length, number of meals and snacks reported for the target period, and, for two school meals, number of meal components reported, importance-weighted number of items reported and kilocalories reported. These variables were transformed to principal components; two were retained (1, the school meal variables; 2, interview length and number of meals and snacks). Analyses of variance on principal component scores tested effects of observation status, target period, interview time and all interactions. Observation status did not affect scores on either retained principal component. Scores on Component 2 showed that more intake was reported in prior-24-hours interviews than in previous-day interviews.

CONCLUSIONS

The effect of target period on reported intake indicates that the response variables were sufficiently reliable to detect manipulations. This, together with the finding that response variables did not depend on observation status, suggests that observation of school meals does not affect fourth-grade children's dietary reports, and that conclusions about dietary reports by fourth-grade children observed eating school meals in validation studies may be generalised to dietary reports by comparable children not observed.

Conventional energy and macronutrient variables distort the accuracy of children's dietary reports: illustrative data from a validation study of effect of order prompts

OBJECTIVE

Validation-study data are used to illustrate that conventional energy and macronutrient (protein, carbohydrate, fat) variables, which disregard accuracy of reported items and amounts, misrepresent reporting accuracy. Reporting-error-sensitive variables are proposed which classify reported items as matches or intrusions, and reported amounts as corresponding or overreported.

METHODS

58 girls and 63 boys were each observed eating school meals on 2 days separated by > or =4 weeks, and interviewed the morning after each observation day. One interview per child had forward-order (morning-to-evening) prompts; one had reverse-order prompts. Original food-item-level analyses found a sex-x-order prompt interaction for omission rates. Current analyses compared reference (observed) and reported information transformed to energy and macronutrients.

RESULTS

Using conventional variables, reported amounts were less than reference amounts (ps<0.001; paired t-tests); report rates were higher for the first than second interview for energy, protein, and carbohydrate (ps< or =0.049; mixed models). Using reporting-error-sensitive variables, correspondence rates were higher for girls with forward- but boys with reverse-order prompts (ps< or =0.041; mixed models); inflation ratios were lower with reverse- than forward-order prompts for energy, carbohydrate, and fat (ps< or =0.045; mixed models).

CONCLUSIONS

Conventional variables overestimated reporting accuracy and masked order prompt and sex effects. Reporting-error-sensitive variables are recommended when assessing accuracy for energy and macronutrients in validation studies.

Body mass index, sex, interview protocol, and children's accuracy for reporting kilocalories observed eaten at school meals

This pilot study investigated body mass index (BMI; calculated as kg/m(2)), sex, interview protocol, and children's accuracy for reporting kilocalories. Forty 4th-grade children (20 low-BMI: >or=5th and <50th percentiles, 10 boys, 15 African American; 20 high-BMI: >or=85th percentile, 10 boys, 15 African American) were observed eating school meals (breakfast, lunch) and interviewed either that evening about the prior 24 hours or the next morning about the previous day, with 10 low-BMI (5 boys) and 10 high-BMI (5 boys) children per interview protocol. Five kilocalorie variables were analyzed using separate four-factor (BMI group, sex, race, interview protocol) analyses of variance. No effects were found for reported or matched kilocalories. More kilocalories were observed (P<0.02) and omitted (P<0.05) by high-BMI than low-BMI children. For intruded kilocalories, means were smaller (better) for high-BMI girls than high-BMI boys, but larger for low-BMI girls than low-BMI boys (interaction P<0.04); low-BMI girls intruded the most while high-BMI girls intruded the least. For interview protocol, omitted and intruded kilocalories were higher (worse), although not significantly so (P values <0.11), for interviews about the previous day than the prior 24 hours. These results illuminate relations of BMI, sex, interview protocol, and children's reporting accuracy, and are consistent with results concerning BMI and sex from studies with adults.

Children's dietary reporting accuracy over multiple 24-hour recalls varies by body mass index category

This secondary analysis investigated the influence of body mass index (BMI) category and sex on reporting accuracy during multiple 24-hour dietary recalls. On three occasions, each of 79 children (40 girls) was observed eating school meals and interviewed the next morning about the previous day's intake, with ≥ 25 days between any two consecutive occasions for a child. Using age/sex BMI percentiles, we categorized 48 children as healthy weight (≥ 5(th) percentile <85(th)), 14 as at risk of overweight (≥ 85(th) percentile <95(th)), and 17 as overweight (≥95(th) percentile). A repeated-measures analysis was conducted for each of five outcomes (number of items observed eaten, number of items reported eaten, omission rate, intrusion rate, total inaccuracy). For items observed, BMI category x trial was marginally significant (P=0.079); over trials, this outcome was stable for healthy-weight children, decreased and stabilized for at-risk-of-overweight children, and was stable and decreased for overweight children. This outcome was greatest for overweight children and least for healthy-weight children (P=0.015). For items reported, no significant effects were found. For omission rate (P=0.028) and intrusion rate (P=0.083), BMI category x trial was significant and marginally significant; over trials, both decreased for healthy-weight children, decreased and stabilized for at-risk-of-overweight children, and increased and stabilized for overweight children. Total inaccuracy decreased slightly over trials (P=0.076); this outcome was greater for boys than for girls (P=0.049). Results suggest that children's dietary reporting accuracy over multiple recalls varies by BMI category. Validation studies with adequate samples for each BMI category, sex, and race are needed.

Assessment of interobserver reliability in nutrition studies that use direct observation of school meals

This article (a) provides a general review of interobserver reliability (IOR) and (b) describes our method for assessing IOR for items and amounts consumed during school meals for a series of studies regarding the accuracy of fourth-grade children's dietary recalls validated with direct observation of school meals. A widely used validation method for dietary assessment is direct observation of meals. Although many studies utilize several people to conduct direct observations, few published studies indicate whether IOR was assessed. Assessment of IOR is necessary to determine that the information collected does not depend on who conducted the observation. Two strengths of our method for assessing IOR are that IOR was assessed regularly throughout the data collection period and that IOR was assessed for foods at the item and amount level instead of at the nutrient level. Adequate agreement among observers is essential to the reasoning behind using observation as a validation tool. Readers are encouraged to question the results of studies that fail to mention and/or to include the results for assessment of IOR when multiple people have conducted observations.