24-Hour national dietary survey data : how do we interpret them most effectively?

Objective To illustrate the effect of common mistakes when using 24-hour national dietary survey data to estimate the prevalence of inadequate nutrient intakes.

Design Raw data on nutrient intake from the Australian 1995 National Nutrition Survey were adjusted for within-person variance using standard techniques and corrected for underreporting using the criteria of Goldberg et al. The distributions for six nutrients were compared with current dietary reference values from the UK, USA and Australia.

Setting A national sample of the Australian population with a 61.4% response rate.

Results Adjusting for within-person variance reduced the range of nutrient intakes to 66–80% of the raw data range and the proportion with intakes below the estimated average requirement (EAR) by up to 20%. Excluding underreporters further reduced the proportion below the EAR by up to 10%. Using the dietary reference values from different countries also resulted in some markedly different estimates. For example, the prevalence of low folate intakes ranged from <1 to 92% for adult women depending on the reference used. Except for vitamin A and protein, the prevalence of low intakes was invariably higher for women than for men.

Conclusions Estimates of the prevalence of low nutrient intakes based on raw 24-hour survey data are invariably misleading. However, even after adjustment for within-person variance and underreporting, estimates of the prevalence of low nutrient intakes may still be misleading unless interpreted in the light of the reference criteria used and supported by relevant biochemical and physiological measures of nutritional status.

Consumption of 'extra' foods (energy-dense, nutrient poor) among children aged 16-24 months from western Sydney, Australia

Objective: This study evaluates the contribution of energy-dense, nutrient-poor ‘extra’ foods to the diets of 16–24-month-old children from western Sydney, Australia.

Design:   An analysis of cross-sectional data collected on participants in the Childhood Asthma Prevention Study (CAPS), a randomised trial investigating the primary prevention of asthma from birth to 5 years. We collected 3-day weighed food records, calculated nutrient intakes, classified recorded foods into major food groups, and further classified foods as either ‘core’ or ‘extras’ according to the Australian Guide to Healthy Eating.

Setting:  Pregnant women, whose unborn child was at risk of developing asthma because of a family history, were recruited from all six hospitals in western Sydney, Australia. Data for this study were collected in clinic visits and at participants’ homes at the 18-month assessment.

Participants: Four hundred and twenty-nine children participating in the CAPS study; 80% of the total cohort.

Results:  The mean consumption of ‘extra’ foods was xs223C150 g day− 1 and contributed 25–30% of the total energy, fat, carbohydrate and sodium to the diets of the study children. ‘Extra’ foods also contributed around 20% of fibre, 10% of protein and zinc, and about 5% of calcium. Children in the highest quintile of ‘extra’ foods intake had a slightly higher but not significantly different intake of energy from those in the lowest quintile. However, significant differences were evident for the percentage of energy provided by carbohydrate and sugars (higher) and protein and saturated fat (lower). The intake of most micronutrients was also significantly lower among children in the highest quintile of consumption. The intake of ‘extra’ foods was inversely associated with the intake of core foods.

Conclusions:  The high percentage of energy contributed by ‘extra’ foods and their negative association with nutrient density emphasise the need for dietary guidance for parents of children aged 1–2 years. These preliminary data on commonly consumed ‘extra’ foods and portion sizes may inform age-specific dietary assessment methods.

Effectiveness of a modified mother–infant transaction program on outcomes for preterm infants from 3 to 24 months of age

Mothers of hospitalised preterm infants were randomised into an intervention or control condition. Intervention mothers received a modified Mother–Infant Transaction Program over seven sessions prior to infant discharge and two sessions over the next 3 months. Infant temperament, mother–infant interaction and parenting stress were assessed at 3 and 6 months and infant development was measured by parental report at 24 months. Intervention compared with control dyads showed enhanced mother–infant interactions, infants were temperamentally more “approaching” and “easier”, had fewer regulatory problems (colic, sleep, excessive crying), and had more developed communication skills, while mothers were less stressed by their infant at 3 months. These early gains in the development of preterm infants and in the relationship with and adjustment of their mothers, may explain the process by which intervention infants in the original study showed increasing cognitive advantages to 9 years of age [Rauh, V. A., Nurcombe, B., Achenbach, T., & Howell, C. (1990). The mother–infant transaction program. Clinical Perinatology, 17, 31–45].

Assessing the intake of obesity-related foods and beverages in young children: comparison of a simple population survey with 24 hr-recall

Background: With an increasing focus on obesity prevention there is a need for simple, valid tools to assess dietary indicators that may be the targets of  intervention programs. The objective of this study was to determine the relative  validity of previous day dietary intake using a newly developed parent-proxy  questionnaire (EPAQ) for two to five year old children.

Methods: A convenience sample of participants (n = 90) recruited through preschools and the community in Geelong, Australia provided dietary data for their child via EPAQ and interviewer administered 24-hour dietary recall (24 hr-recall). Comparison of mean food and beverage group servings between the  EPAQ and 24 hr-recall was conducted and Spearman rank correlations were computed to examine the association between the two methods.

Results: Mean servings of food/beverage groups were comparable between methods for all groups except water, and significant correlations were found between the servings of food and beverages using the EPAQ and 24-hr recall methods (ranging from 0.57 to 0.88).

Conclusion: The EPAQ is a simple and useful population-level tool for  estimating the intake of obesity-related foods and beverages in children aged two to five years. When compared with 24-hour recall data, the EPAQ produced an acceptable level of relative validity and this short survey has application for population monitoring and the evaluation of population-based obesity prevention interventions for young children.

The place: Jan 24 - Feb 13 2011

A review of John Forrest's 2011 exhibition The place.

A prospective study of the impact of subthreshold mixed states on the 24-month clinical outcomes of bipolar I disorder or schizoaffective disorder

Objectives: Subthreshold mixed states are common, yet their clinical significance is unclear. This study investigated the clinical outcomes of subthreshold mixed states in participants with bipolarI disorder or schizoaffective disorder, using the Cassidy and Benazzi criteria for manic and depressive mixed states, respectively.

Methods: The Bipolar Comprehensive Outcomes Study (BCOS) is a prospective observational study of treatment and outcomes for patients with bipolar I or schizoaffective disorder, bipolar type. Participants (N=239) were grouped based on study entry clinical presentation as having pure depression (n=63) if they satisfied DSM-IV-TR criteria for a Major Depressive Episode (MDE), depressive mixed state (DMX) if they also had at least three concurrent hypomanic symptoms (n=33), or not depressed (n=143) if they did not satisfy the criteria for MDE. Participants were similarly grouped as having pure mania (n=3) if they satisfied DSM-IV criteria for a Manic Episode, manic mixed state (MMX) if they also had at least two concurrent depressive symptoms (n=33), or not manic (n=203). Clinical data were collected by interview every 3-months over a 24-month period.

Results: Measures of quality of life, mental and physical health over the 24-month period were significantly worse for participants who were classified as having mixed states at study entry on most outcome measures compared to participants who were not in an illness episode at study entry. DMX was predictive of greater manic symptomatology over the 24 months compared to participants with pure depression.

Conclusion: In participants with a current episode of mood disorder, the presence of subthreshold symptoms of opposite polarity was associated with poorer clinical outcomes over a 24-month period.