Gehan Roberts

Murdoch Childrens Research Institute, Melbourne, Victoria, Australia

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Publications (47)161.62 Total impact

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    ABSTRACT: Multiple imputation (MI), a two-stage process whereby missing data are imputed multiple times and the resulting estimates of the parameter(s) of interest are combined across the completed datasets, is becoming increasingly popular for handling missing data. However, MI can result in biased inference if not carried out appropriately or if the underlying assumptions are not justifiable. Despite this, there remains a scarcity of guidelines for carrying out MI. In this paper we provide a tutorial on the main issues involved in employing MI, as well as highlighting some common pitfalls and misconceptions, and areas requiring further development. When contemplating using MI we must first consider whether it is likely to offer gains (reduced bias or increased precision) over alternative methods of analysis. Once it has been decided to use MI, there are a number of decisions that must be made during the imputation process; we discuss the extent to which these decisions can be guided by the current literature. Finally we highlight the importance of checking the fit of the imputation model. This process is illustrated using a case study in which we impute missing outcome data in a five-wave longitudinal study that compared extremely preterm individuals with term-born controls.
    No preview · Article · Feb 2016 · International Journal of Social Research Methodology
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    ABSTRACT: Background: Extremely preterm (EP, <28 weeks' gestation) individuals have increased risk of cognitive deficits compared with controls. The posterior cingulate region has an important role in cognitive function, but how this is affected by preterm birth is unknown. We aimed to compare brain metabolite ratios of neurons and cell membranes between EP 18-year-olds and controls, and explore the association between metabolite ratios and cognitive outcomes. Method: A regional cohort of 150 EP and 134 controls. Cerebral metabolites were measured using proton MRS obtained from a left posterior cingulate voxel. Total N-acetylaspartate(tNAA, neuronal marker)/total creatine(tCr) and total choline(tCho, cell membrane marker)/tCr ratios were compared between groups using linear regression. Metabolite ratios were correlated with tests of general intelligence (IQ), memory and attention using linear or logistic regression. Results: Compared with controls, EP had lower tNAA/tCr (mean difference [95% CI] of -2.27%[-4.09, -0.45]) and tCho/tCr (mean difference [95% CI] of -11.11%[-20.37, -1.85]), all p=0.02. Higher tCho/tCr correlated with better IQ in the EP group only; whereas higher tNAA/tCr ratios correlated with better scores in working memory and attention in both groups. Conclusion: EP birth is associated with long-term brain metabolite ratio alterations. This may underlie poorer cognitive performance in EP survivors.Pediatric Research (2016); doi:10.1038/pr.2015.272.
    No preview · Article · Jan 2016 · Pediatric Research
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    ABSTRACT: Background and objectives: The importance of biological versus social influences on long-term outcomes of extremely preterm children is debatable. The goal of this study was to determine the relative contributions of biological and social exposures to outcomes into adolescence in extremely preterm survivors, hypothesizing that biological exposures would be more important early, but social exposures would dominate later. Methods: The study included 298 consecutive survivors born at <28 weeks' gestation or weighing <1000 g in Victoria, Australia (during 1991-1992), and 262 normal birth weight (>2499 g) control subjects who were used to standardize outcomes for the preterm group. Cognitive ability was assessed at 2, 5, 8, and 18 years of age. Academic achievement was assessed at 8 and 18 years of age. Results: The differences between the preterm and control groups for cognitive and academic scores remained relatively constant over time. The biological variables most associated with worse outcomes within the extremely preterm group were intraventricular hemorrhage and postnatal corticosteroid therapy. Of the social variables, being reared in a multilingual household was disadvantageous early, with social class and maternal education becoming more important for later outcomes. The strength of the biological associations mostly equaled or exceeded those of social exposures, even in late adolescence. Conclusions: Contrary to expectations, several perinatal biological exposures had large and persistent adverse associations with cognitive and academic outcomes among extremely preterm survivors. As expected, some social variables assumed increasing importance in later years but mostly did not diminish or exceed the important biological associations.
    No preview · Article · Nov 2015 · Pediatrics
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    ABSTRACT: Background: Children born extremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) have more academic deficiencies than their term-born peers, which may be due to problems with visual processing. Aim: To determine; (1) if visual processing is related to poor academic outcomes in EP/ELBW adolescents, and (2) how much of the variance in academic achievement in EP/ELBW adolescents is explained by visual processing ability after controlling for perinatal risk factors and other known contributors to academic performance, particularly attention and working memory. Method: A geographically determined cohort of 228 surviving EP/ELBW adolescents (mean age 17 years) was studied. The relationships between measures of visual processing (visual acuity, binocular stereopsis, eye convergence, and visual perception) and academic achievement were explored within the EP/ELBW group. Analyses were repeated controlling for perinatal and social risk, and measures of attention and working memory. Results: Visual acuity, convergence and visual perception were related to scores for academic achievement on univariable regression analyses. After controlling for potential confounds (perinatal and social risk, working memory and attention), visual acuity, convergence and visual perception remained associated with reading and math computation, but only convergence and visual perception were related to spelling. The additional variance explained by visual processing was up to 6.6% for Reading, 2.7% for Spelling, and 2.2% for Math Computation. None of the visual processing variables or visual motor integration was associated with handwriting on multivariable analysis. Working memory was generally a stronger predictor of reading, spelling, and math computation than visual processing. Conclusions: Visual processing difficulties are significantly related to academic outcomes in adolescents born EP/ELBW. Specific attention should be paid to academic remediation strategies incorporating management of working memory and visual processing in EP/ELBW children.
    No preview · Article · Nov 2015 · Child Neuropsychology
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    ABSTRACT: Very preterm (VP) survivors are at increased risk of autism spectrum disorder (ASD) compared with term-born children. This study explored whether neonatal magnetic resonance (MR) brain features differed in VP children with and without ASD at 7 years. One hundred and seventy-two VP children (<30 weeks' gestation or <1250 g birth weight) underwent structural brain MR scans at term equivalent age (TEA; 40 weeks' gestation ±2 weeks) and were assessed for ASD at 7 years of age. The presence and severity of white matter, cortical gray matter, deep nuclear gray matter, and cerebellar abnormalities were assessed, and total and regional brain volumes were measured. ASD was diagnosed using a standardized parent report diagnostic interview and confirmed via an independent assessment. Eight VP children (4.7%) were diagnosed with ASD. Children with ASD had more cystic lesions in the cortical white matter at TEA compared with those without ASD (odds ratio [OR] 8.7, 95% confidence interval [CI] 1.5, 51.3, P = 0.02). There was also some evidence for smaller cerebellar volumes in children with ASD compared with those without ASD (OR = 0.82, CI = 0.66, 1.00, P = 0.06). Overall, the results suggest that VP children with ASD have different brain structure in the neonatal period compared with those who do not have ASD. Autism Res 2015. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.
    No preview · Article · Oct 2015 · Autism Research
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    ABSTRACT: AimExtremely preterm (EPT, born <28 weeks gestation) or extremely low birthweight (ELBW, birthweight <1000 g) individuals are at increased risk of high blood pressure (BP) and cardiovascular disease. We compared office BP measurements with 24-h ambulatory BP measurement (ABP) in EPT/ELBW individuals at age 18 years and term controls, and determined the sensitivity and specificity of office BP in predicting masked hypertension (24-h ABP measurements > 130/80).Methods All EPT/ELBW individuals and matched term control adolescents born in Victoria, Australia, between 1991 and 1992 were recruited. A subset of this cohort was seen at 18 years, and researchers blinded to birth status measured office BP and ABP. We established the office BP thresholds that had the highest sensitivity and specificity in predicting masked hypertension.ResultsEPT/ELBW (N = 120) individuals had higher mean BP measurements at 18 years, compared with controls (N = 71). Although there were no significant differences in rates of high BP between groups, high proportions of both EPT/ELBW (43.3%) and term control (36.6%) participants met criteria for masked systolic hypertension. In EPT/ELBW individuals, office systolic BP measurement of ≥122.5 mmHg predicted masked systolic hypertension (sensitivity 79%, specificity 74%). Office diastolic BP measurement of ≥75.5 mmHg predicted masked diastolic hypertension (sensitivity 77%, specificity, 77%).Conclusions At age 18 years, EPT/ELBW individuals have higher systolic and diastolic BP, compared with controls. Office BP may be an adequate screen for masked hypertension in EPT/ELBW survivors, but further research is needed to identify accurate ABP thresholds for masked hypertension for young Australians.
    No preview · Article · Jul 2015 · Journal of Paediatrics and Child Health
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    ABSTRACT: Neonatal intensive care is expensive, and thus it is essential that its long-term outcomes are measured. The costs of follow-up studies for high-risk children who survive are unknown. This study aims to determine current costs for the assessment of health and development of children followed up in our research programme. Costs were determined for children involved in the research follow-up programme at the Royal Women's Hospital, Melbourne, over the 6-month period between 1st January 2012 and 30th June 2012. The time required for health professionals involved in assessments in early and later childhood was estimated, and converted into dollar costs. Costs for equipment and data management were added. Estimated costs were compared with actual costs of running the research follow-up programme. A total of 134 children were assessed over the 6-month period. The estimated average cost per child assessed was $1184, much higher than was expected. The estimated cost to assess a toddler was $1149, whereas for an 11-year-old it was $1443, the difference attributable to the longer psychological and paediatric assessments. The actual average cost per child assessed was $1623. The shortfall of $439 between the actual and estimated average costs per child arose chiefly because of the need to pay staff even when participants were late or failed to attend. The average costs of assessing children at each age for research studies are much higher than expected. These data are useful for planning similar long-term follow-up assessments for high-risk children. © 2015 The Authors. Journal of Paediatrics and Child Health © 2015 Paediatrics and Child Health Division (Royal Australasian College of Physicians).
    No preview · Article · Apr 2015 · Journal of Paediatrics and Child Health
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    ABSTRACT: Extremely preterm (EP; <28 weeks) birth and extremely low birth weight (ELBW; <1000 g) are risk factors for poor cognitive outcomes, including in executive function (EF; higher-order cognitive skills necessary for goal-directed, adaptive functioning and important for academic and behavioral-emotional outcomes). We aimed to (1) extend the limited data on EF in EP/ELBW survivors in adolescence compared with normal birth weight controls, and (2) determine changes in EF between ages 8 and 17 years in both groups. Two hundred twenty-eight EP/ELBW and 166 control adolescents (mean age, 17 years) from a prospective geographical cohort were assessed with multiple EF tasks, and parent- and self-ratings of behavioral EF. The Rey Complex Figure and Behavior Rating Inventory of Executive Function parent report were also administered at age 8 years, enabling examination of change in scores between childhood and adolescence. EP/ELBW adolescents performed more poorly than controls in verbal processing speed, attentional control, cognitive flexibility, and goal-setting (effect sizes, -0.7 to -0.2 SD), but not psychomotor reaction time. Group differences were of similar magnitude across tasks. From childhood to late adolescence, EP/ELBW children improved their accuracy of the Rey Complex Figure copy more than controls. According to parents, executive behaviors were largely stable over time in both groups. Adolescents born EP/ELBW have poorer EF skills across multiple domains than controls. From childhood to late adolescence, different aspects of EF improved, but others did not, underscoring the need for multidomain, longitudinal assessments in this high-risk population. Copyright © 2015 by the American Academy of Pediatrics.
    Preview · Article · Mar 2015 · PEDIATRICS
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    ABSTRACT: Poor sleep and working memory difficulties are both associated with learning difficulties, but it is not known whether they are linked with each other in childhood. We aimed to determine, in a population-based sample of grade 1 children, whether poor sleep is associated with reduced working memory capacity. Cross-sectional population-based study. All grade 1 children in 44 elementary schools in metropolitan Melbourne, Australia; 1749 children were included (participation rate 65%, mean age 6.9 years). Parents completed a written questionnaire at home, after which researchers administered one-on-one child computerized assessments at school. Predictor measures were parent-reported 1) perceptions of poor sleep, 2) regularity of bedtime, 3) sleep duration, and 4) sleep onset latency. Outcome measures were backward digit recall (verbal working memory) and Mister X (visuospatial working memory) subtests of the Automated Working Memory Assessment (AWMA). Associations were examined using linear regression, adjusted for duration of schooling, gender, age, and social status. Increasing poor sleep (P = .03), less regularity of bedtime (P < .001), and shorter sleep duration (P = .03) were all associated with poorer verbal working memory, with effect sizes ranging from 0.3 to 1.2. Poor sleep was not associated with visuospatial working memory. At a population level, poor sleep in early school-age children is associated with poorer verbal working memory, an important predictor of academic difficulties. Copyright © 2015 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Feb 2015 · Academic Pediatrics
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    ABSTRACT: Low working memory (WM) is strongly linked with poor academic outcomes. WM capacity increases across childhood but how exposure to school is associated with WM development is not known. We aimed to determine extent to which chronological age and schooling duration are associated with WM at the population level. In 2012, children in Grade 1 (the second year of formal schooling in Victoria, Australia) from 44 schools in metropolitan Melbourne were recruited. Assessments occurred over the entire school year, with schools quasi-randomly allocated to one of the 4 school terms. WM (primary outcome) was measured using 2 subtests from the computerized Automated Working Memory Assessment: Backwards Digit Recall (verbal) and Mister X (visuospatial). Linear regression was used to examine relationships of WM with time in school and age. Of the 1765 who provided consent, 1727 children (97.9%) had WM assessed throughout the 2012 school year. WM scores became steadily higher over the course of the year. Thus, scores were .77 and .53 SDs higher in Term 4 than Term 1 for verbal and visuospatial WM, respectively (p values for trend for both scores <.001); conclusions were unchanged when adjusted for age and potential confounders. Conversely, age associations attenuated fully once adjusted for school duration. Our results demonstrate, for the first time, that the developmental increases in WM are strongly associated with time spent in the classroom, above and beyond chronological age.
    No preview · Article · Jan 2015 · Journal of developmental and behavioral pediatrics: JDBP
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    ABSTRACT: Background Most babies are born healthy and grow and develop normally through childhood. There are, however, clearly identifiable high-risk groups of survivors, such as those born preterm or with ill-health, who are destined to have higher than expected rates of health or developmental problems, and for whom more structured and specialised follow-up programs are warranted. Discussion This paper presents the results of a two-day workshop held in Melbourne, Australia, to discuss neonatal populations in need of more structured follow-up and why, in addition to how, such a follow-up programme might be structured. Issues discussed included the ages of follow-up, and the personnel and assessment tools that might be required. Challenges for translating results into both clinical practice and research were identified. Further issues covered included information sharing, best practice for families and research gaps. Summary A substantial minority of high-risk children has long-term medical, developmental and psychological adverse outcomes and will consume extensive health and education services as they grow older. Early intervention to prevent adverse outcomes and the effective integration of services once problems are identified may reduce the prevalence and severity of certain outcomes, and will contribute to an efficient and effective use of health resources. The shared long-term goal for families and professionals is to work toward ensuring that high risk children maximise their potential and become productive and valued members of society. Electronic supplementary material The online version of this article (doi:10.1186/1471-2431-14-279) contains supplementary material, which is available to authorized users.
    Full-text · Article · Nov 2014 · BMC Pediatrics
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    ABSTRACT: Extremely preterm (EP, <28 weeks) and/or extremely low birth weight (ELBW, <1000 g) infants are at high risk of aberrant neurodevelopment. Sulcogyral folding patterns of the orbitofrontal cortex (OFC) are determined during the third trimester, however little is known about OFC patterning in EP/ELBW cohorts, for whom this gestational period is disturbed. This study investigated whether the distribution of OFC pattern types and frequency of intermediate and/or posterior orbital sulci (IOS/POS) differed between EP/ELBW and control adolescents. This study also investigated whether OFC pattern type was associated with mental illness or executive function outcome in adolescence. Magnetic resonance images of 194 EP/ELBW and 147 full term (>37 completed weeks) and/or normal birth weight (>2500 g) adolescents were acquired, from which the OFC pattern of each hemisphere was classified as Type I, II, or III. Compared with controls, more EP/ELBW adolescents possessed a Type II in the left hemisphere (P = 0.019). The EP/ELBW group had fewer IOS (P = 0.024) and more POS (P = 0.021) in the left hemisphere compared with controls. OFC pattern type was not associated with mental illness, however in terms of executive functioning, Type III in the left hemisphere was associated with better parent-reported metacognition scores overall (P = 0.008) and better self-reported behavioral regulation scores in the control group (P = 0.001) compared with Type I. We show, for the first time that EP/ELBW birth is associated with changes in orbitofrontal development, and that specific patterns of OFC folding are associated with executive function at age 18 years in both EP/ELBW and control subjects. Hum Brain Mapp, 2014. © 2014 Wiley Periodicals, Inc.
    No preview · Article · Nov 2014 · Human Brain Mapping
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    ABSTRACT: Objectives To compare brain volumes in adolescents who were born extremely preterm (<28 weeks gestation) who had received postnatal dexamethasone, and to determine if there was a postnatal dexamethasone dose–response effect on brain volumes. Study design Geographical cohort study of extremely preterm adolescents born in 1991-1992 in Victoria, Australia. T1-weighted magnetic resonance imaging was performed at 18 years of age. Segmented and parcellated brain volumes were calculated using an automated segmentation method (FreeSurfer) and compared between groups, with and without adjustment for potential confounders. The relationships between total postnatal dexamethasone dose and brain volumes were explored using linear regression. Results Of the 148 extremely preterm participants, 55 (37%) had received postnatal dexamethasone, with a cumulative mean dose of 7.7 mg/kg. Compared with participants who did not receive postnatal dexamethasone, those who did had smaller total brain tissue volumes (mean difference −3.6%, 95% CI [−7.0%, −0.3%], P value = .04) and smaller white matter, thalami, and basal ganglia volumes (all P < .05). There was a trend of smaller total brain and white matter volumes with increasing dose of postnatal dexamethasone (regression coefficient −7.7 [95% CI −16.2, 0.8] and −3.2 [−6.6, 0.2], respectively). Conclusions Extremely preterm adolescents who received postnatal dexamethasone in the newborn period had smaller total brain tissue volumes than those who did not receive postnatal dexamethasone, particularly white matter, thalami, and basal ganglia. Vulnerability of brain tissues or structures associated with postnatal dexamethasone varies by structure and persists into adolescence.
    Preview · Article · Apr 2014 · The Journal of pediatrics
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    ABSTRACT: Adult preterm survivors from the 1980s have higher blood pressure (BP) than term controls. Survival rates of extremely preterm (gestational age < 28 weeks; EP) infants born after 1990 have increased, but whether they still have higher BP than term controls is unknown. This study compared the BP of contemporary EP survivors with term controls in late adolescence. All EP adolescents and matched term controls born in 1991-92 in Victoria, Australia, were enrolled in a longitudinal study. At age 18 years, 24-h ambulatory BP was measured. Average BP was compared between EP and term groups, and predictors of BP in EP adolescents were examined. BP data were obtained from 136 EP patients and 120 controls. EP patients on average had higher systolic, diastolic and mean BP than controls. The mean systolic difference over 24 h was 3.2 mmHg [95% confidence interval (CI) 0.1-6.4], 3.9 mmHg [95% CI 0.7-7.2] when awake, and 2.0 mmHg (95% CI 1.4-5.5) when asleep. Male sex and change in weight SD score from birth to 2 years were predictive of SBP (regression coefficients 6.2 (95% CI 1.8-10.6), P = 0.006) and 2.0 (95% CI 0.2-3.8), P = 0.032), respectively). SBP at age 8 was associated with BP at age 18 years. Late adolescent EP survivors of the modern era have higher BP compared with term controls. This highlights the importance of long-term cardiovascular surveillance for this increasing group into adulthood.
    No preview · Article · Mar 2014 · Journal of Hypertension
  • Gehan Roberts · Jeanie L.Y. Cheong
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    ABSTRACT: Given the improving survival rates of extremely preterm (EP, gestational age <28 weeks) infants, there is a need to understand their general growth and health outcomes not only in childhood, but also into adulthood. EP children are shorter and lighter compared with term children at term-equivalent age; with time, the weight disadvantage diminishes but the height disadvantage remains relatively unchanged. EP children and young adults also have higher rates of reported health concerns, medical conditions and visual impairment. Hospital readmissions are higher in early childhood, mostly attributed to respiratory illness. Individuals born EP have reduced bone health and are at increased risk for metabolic disorders. Increased rates of conditions such as diabetes or pathological fractures are not reported in the literature, although follow-up studies so far have only tracked EP individuals into young adulthood. Consequently, health care utilization and costs are increased in EP children and young adults. A thorough knowledge of the health risks related to EP birth is essential in planning surveillance and intervention strategies to optimize their health and wellbeing. Despite the increased risk of health problems, EP young adults generally report their quality of life to be similar to that reported in their term counterparts.
    No preview · Article · Nov 2013 · Seminars in Fetal and Neonatal Medicine
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    ABSTRACT: Extremely preterm (EP) survivors have smaller brains, lower IQ, and worse educational achievement than their term-born peers. The contribution of smaller brain size to the IQ and educational disadvantages of EP is unknown. This study aimed (i) to compare brain volumes from multiple brain tissues and structures between EP-born (<28weeks) and term-born (≥37weeks) control adolescents, (ii) to explore the relationships of brain tissue volumes with IQ and basic educational skills and whether this differed by group, and (iii) to explore how much total brain tissue volume explains the underperformance of EP adolescents compared with controls.
    Full-text · Article · Oct 2013 · PLoS ONE
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    ABSTRACT: The aim of this study was to evaluate attention difficulties in a contemporary geographic cohort of adolescents born extremely preterm (EP, <28 weeks' gestation) or extremely low birth weight (ELBW, birth weight <1000 g). The EP/ELBW group included 228 adolescents (mean age = 17.0 years) born in Victoria, Australia in 1991 and 1992. The control group were 166 adolescents (mean age = 17.4 years) born of normal birth weight (birth weight >2499 g) who were recruited in the newborn period and matched to the EP/ELBW group on date of birth, gender, language spoken and health insurance status. Participants were assessed on measures of selective, sustained, and executive (shift and divided) attention, and parents and participants completed behavioral reports. The EP/ELBW group performed more poorly across tests of selective and executive attention, had greater rates of clinically significant difficulties compared with the control group, and also had greater behavioral attention problems as reported by parents. Neonatal risk factors were weakly associated with attention outcomes. In conclusion, higher rates of attention impairments are observed in individuals born EP/ELBW well into adolescence and may have consequences for their transition to adulthood. (JINS, 2013, 19, 1-12).
    Full-text · Article · Sep 2013 · Journal of the International Neuropsychological Society
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    ABSTRACT: Very preterm children exhibit difficulties in working memory, a key cognitive ability vital to learning information and the development of academic skills. Previous research suggests that an adaptive working memory training intervention (Cogmed) may improve working memory and other cognitive and behavioural domains, although further randomised controlled trials employing long-term outcomes are needed, and with populations at risk for working memory deficits, such as children born preterm.In a cohort of extremely preterm (<28 weeks' gestation)/extremely low birthweight (<1000 g) 7-year-olds, we will assess the effectiveness of Cogmed in improving academic functioning 2 years' post-intervention. Secondary objectives are to assess the effectiveness of Cogmed in improving working memory and attention 2 weeks', 12 months' and 24 months' post-intervention, and to investigate training related neuroplasticity in working memory neural networks 2 weeks' post-intervention. This double-blind, placebo-controlled, randomised controlled trial aims to recruit 126 extremely preterm/extremely low birthweight 7-year-old children. Children attending mainstream school without major intellectual, sensory or physical impairments will be eligible. Participating children will undergo an extensive baseline cognitive assessment before being randomised to either an adaptive or placebo (non-adaptive) version of Cogmed. Cogmed is a computerised working memory training program consisting of 25 sessions completed over a 5 to 7 week period. Each training session takes approximately 35 minutes and will be completed in the child's home. Structural, diffusion and functional Magnetic Resonance Imaging, which is optional for participants, will be completed prior to and 2 weeks following the training period. Follow-up assessments focusing on academic skills (primary outcome), working memory and attention (secondary outcomes) will be conducted at 2 weeks', 12 months' and 24 months' post-intervention. To our knowledge, this study will be the first randomised controlled trial to (a) assess the effectiveness of Cogmed in school-aged extremely preterm/extremely low birthweight children, while incorporating advanced imaging techniques to investigate neural changes associated with adaptive working memory training, and (b) employ long-term follow-up to assess the potential benefit of improved working memory on academic functioning. If effective, Cogmed would serve as a valuable, available intervention for improving developmental outcomes for this population.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12612000124831.
    Full-text · Article · Sep 2013 · BMC Pediatrics
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    ABSTRACT: Background and objectives: Ocular growth and development differs between preterm and term-born infants and may cause long-term negative consequences for visual function, but contemporary data on long-term visual outcomes in representative samples of the highest risk extremely low birth weight (ELBW, <1000 g birth weight) or extremely preterm (EP, <28 weeks' gestation) survivors are lacking. Our objective was to compare visual functioning between ELBW/EP and normal birth weight (NBW, >2499 g birth weight) control adolescents. Methods: Geographically determined cohort study of 228 consecutive ELBW/EP survivors born in the state of Victoria in 1991 and 1992, and 166 randomly selected NBW controls assessed between 14 and 20 years of age. Visual acuity, stereopsis, convergence, color perception, and visual perception were assessed and contrasted between groups. Results: ELBW/EP subjects had significantly worse visual acuity with habitual correction in both the left and right eyes, and for the best eye (P < .001). The ELBW/EP adolescents also exhibited poorer stereopsis, odds ratio (OR) 3.22 (95% confidence interval [CI] 1.78 to 5.84), and convergence, OR 2.76 (CI 1.32 to 5.75) than controls, and more problems with visual perception, OR 3.09 (CI 1.67 to 5.71) after habitual correction. Conclusions: Despite advances in medical care improving the survival rate of high-risk ELBW/EP infants, visual morbidity is still relatively high compared with controls in late adolescence.
    Full-text · Article · Sep 2013 · Pediatrics
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    ABSTRACT: Using magnetic resonance imaging, this study compared hippocampal volume between 145 very preterm children and 34 children born full-term at 7 years of age. The relationship between hippocampal volume and memory and learning impairments at 7 years was also investigated. Manual hippocampal segmentation and subsequent three-dimensional volumetric analysis revealed reduced hippocampal volumes in very preterm children compared with term peers. However, this relationship did not remain after correcting for whole brain volume and neonatal brain abnormality. Contrary to expectations, hippocampal volume in the very preterm cohort was not related to memory and learning outcomes. Further research investigating the effects of very preterm birth on more extensive networks in the brain that support memory and learning in middle childhood is needed. (JINS, 2013, 19, 1-11).
    Full-text · Article · Aug 2013 · Journal of the International Neuropsychological Society

Publication Stats

864 Citations
161.62 Total Impact Points

Institutions

  • 2010-2015
    • Murdoch Childrens Research Institute
      Melbourne, Victoria, Australia
  • 2009-2015
    • The Royal Children's Hospital
      • Department of Neonatal Medicine
      Melbourne, Victoria, Australia
  • 2008-2015
    • University of Melbourne
      • • Department of Paediatrics
      • • Department of Obstetrics and Gynaecology
      Melbourne, Victoria, Australia