Tag Archives: Child development

Keeping a Child Back at School

We have often talked about Hattie’s work on evidence-based education.[1-4] Now we turn to retention (pages 97-99) – the act of keeping a child back and having them repeat a year of school on the grounds of poor performance.[5] Numerous papers, including a meta-analysis of 20 studies,[6] have shown retention to be associated with negative effects for the retained student. In subsequent years they have lower scores for a whole range of subjects: language, arts, reading, mathematics, work-study skills, and social studies, as well as social and emotional adjustment and behaviour, self-concept, and attitude to school. So a picture is starting to emerge – remember streaming is also unhelpful.[7] So any act that demeans a child or destroys her self-confidence is bad, while bright children are not held back by having less bright peers in the classroom. See also our News Blog on the Michelle Obama effect.[8]

— Richard Lilford, CLAHRC WM Director

References:

  1. Lilford RJ. Evidence-based Education. NIHR CLAHRC West Midlands News Blog. 24 February 2017.
  2. Lilford RJ. The School, the Teacher of the Pupil – Which is Most Important? NIHR CLAHRC West Midlands News Blog. 28 October 2016.
  3. Lilford RJ. Ask Not to Whether, But Why, Before the Bell Tolls. NIHR CLAHRC West Midlands News Blog. 29 July 2016.
  4. Lilford RJ. Education Update. NIHR CLAHRC West Midlands News Blog. 2 September 2016.
  5. Hattie J. Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement. Oxon, UK: Routledge, 2009.
  6. Jimerson SR. Meta-analysis of Grade Retention Research: Implications for Practice in the 21st Century. School Psychol Rev. 2001; 30(3): 420-37.
  7. Lilford RJ. Evidence-Based Education (or How Wrong the CLAHRC WM Director Was). NIHR CLAHRC West Midlands News Blog. 15 July 2016.
  8. Lilford RJ. More on Education. NIHR CLAHRC West Midlands News Blog. 16 September 2016.

More on Brain Health in Young Children and Effect on Life Course

Brain health in early childhood is a recurring theme of your News Blog. Peter Chilton referred me to an interesting article in Nature Human Behaviour published at the end of last year.[1] This study was based on a prospective study of children in the South Island of New Zealand. The investigators wanted to determine the prognosis for the 20% of the population with the worst brain health indicators at age three. These indicators include single parent family; low socioeconomic group; poor self-control; and low IQ. Outcome variables covered a range of important economically burdensome outcomes, such as obesity, cigarette smoking, and crime. These variables were harvested from various databases where health and crime statistics are recorded. A 20% ‘segment’ of this young population could be defined which predicted 80% of crime, and similar high rates on other outcomes. This 20:80 ratio, called the Pareto ratio, is often encountered in social science – for example, wealth distributes itself roughly in this proportion across many societies (about 20% of people control 80% of wealth). The authors say that their study shows plenty of ‘headroom’ for preventive interventions. That is to say, society could achieve massive gains if health and social outcomes among the highest risk segment could be improved to average levels. We have discussed interventions, such as early childhood education, before.[2-4] Many studies show statistically significant and economically worthwhile results for such interventions, but the gains come nowhere near the theoretical headroom defined here. Likely this is because brain health at age three is only partly the result of remediable factors.

— Richard Lilford, CLAHRC WM Director

References:

  1. Caspi A, Houts RM, Belsky DW, Harrington H, Hogan S, Ramrakha S, Poulton R, Moffitt TE. Childhood forecasting of a small segment of the population with large economic burden. Nature Hum Behav. 2016; 1: 0005.
  2. Lilford RJ. Pregnancy before age 16 – dropping quite rapidly from a peak in 1997. NIHR CLAHRC West Midlands News Blog. February 10, 2017.
  3. Lilford RJ. If you want to reduce partner violence or teenage pregnancy, then teach algebra and history? NIHR CLAHRC West Midlands News Blog. December 9, 2016.
  4. Lilford RJ. Evidence-based education (or how wrong the CLAHRC WM Director was). NIHR CLAHRC West Midlands News Blog. July 15, 2016.

Another Day, Another (Badly-Reported) Health Story in the Media…

Recent health issues reported in the British media have included the link between consumption of red and processed meat with an increased risk of cancer and the need for a ‘sugar tax’ to curb the ever-increasing rates of obesity and its associated health problems. These are big, newsworthy issues relating to the effect of diet and lifestyle on health: the World Cancer Research Fund estimate that around 6,000 cases of bowel cancer in the UK could be prevented by reducing consumption of red and processed meat,[1] while a 20p/litre tax on sugar-sweetened beverages could reduce the number of obese adults in the UK by 180,000 according to the Faculty of Public Health.[2]

So one has to feel a little pity for a journalist tasked with writing a piece about a study investigating whether the composition of a mother’s breast milk was associated with infant weight and body composition.[3] The journalist from The Times seemed to approach this task by jumping on the obesity bandwagon; two key quotes from the story are: “A mother’s milk can increase the chance of a child growing up obese” and “A study … identified sugars in breastmilk that heightened a baby’s risk of being overweight by the age of 6 months”. This seemed to fly in the face of almost everything I had ever read about breastfeeding, so I decided to look at the evidence in a bit more detail.

The paper was based on a sample of 25 breastfeeding mothers and their babies. No babies were formula-fed. Outcomes were infant growth (weight and length) and body composition (percentage fat, total fat and lean mass). Whether or not the baby was ‘overweight’ or ‘obese’ was not an outcome. An association between the level of different human milk oligosaccharides (HMOs) in breast milk and infant weight and body composition was identified by the study authors, adding to the evidence base regarding the factors influencing a baby’s growth and development. The authors themselves made no direct claim that breastfeeding causes childhood obesity (three separate meta-analyses have, in fact, shown the opposite [4-6]), with the smallest of these studies including data for almost 30,000 babies.

The journalist’s train of thought may have gone thus:

44 GB Health Story in Media Fig 1

The first step in this chain was identified by the study authors. But was the journalist justified in making the second?

The increase in risk of adulthood obesity given a high weight-for-age percentile in infancy has been known for some time,[7] so the second link is plausible. But can it automatically be inferred from this study? To do so relies on the increases in body fat/fat mass being of such magnitude to class some of the infants in this study as overweight or obese at six months and we simply don’t know if this was the case. Instead, it could be possible that babies receiving alternative combinations of HMOs to those shown in the diagram were actually underweight and that those at the upper end of the weight range were still of ‘normal’ weight. We also don’t know how the weights and body compositions of the babies in the study would compare to those who have been formula-fed: even if breast milk containing high levels of certain HMOs did increase the risk of obesity, the risk with such HMOs could still be lower than that from infant formula.

That some HMOs were shown to have a negative relationship with body weight and/or composition seemed to make the journalist even more confused, since the story ended by stating “However, scientists also found that breast milk could protect against obesity.” The meta-analyses quoted above have demonstrated this, but once again, such a conclusion cannot be drawn from this particular study.
Reporting of current research in the media is invaluable to help increase uptake of its findings, yet the dangerous misinterpretation of the findings of the study by Alderete et al. mean that I hope the story in The Times (not the research study) was ignored by all who read it.

— Celia Taylor

References:

  1. World Cancer Research Fund. Bowel cancer. 2015. [Online]
  2. Faculty of Public Health. A duty on sugar sweetened beverages. A position statement. 2013. [Online]
  3. Alderete TL, Autran C, Brekke BE, et al. Associations between human milk oligosaccharides and infant body composition in the first 6 mo of life. Am J Clin Nutr. 2015. [ePub].
  4. Arenz S, Rückerl R, Boletzko B, von Kries R. Breast-feeding and childhood obesity – a systematic review. Int J Obesity. 2004; 28: 1247-56.
  5. Owen C, Martin R, Whincup P et al. The effect of breastfeeding on mean body mass index throughout life: a quantitative review of published and unpublished observational evidence. Am J Clin Nutr. 2005; 82: 1298-1307.
  6. Harder T, Bergman R, Kallischnigg G et al. Duration of breastfeeding and risk of overweight: a meta-analysis. Am J Epidemiol. 2005; 162:397-403.
  7. Charney E, Goodman HC, McBride M, et al. Childhood Antecedents of Adult Obesity – Do Chubby Infants Become Obese Adults? N Engl J Med. 1976; 295: 6-9.

So Does Breastfeeding Increase Children’s IQ?

News Blog readers will have seen a short report on the Lancet article from Brazil associating breastfeeding with improved IQ.[1] Alas, probably not correct: at least any effect must be very small, according to a recent article that greatly improves on the Lancet paper.[2] First, the authors cite a thorough systematic review published in BMJ Open [3] and conclude that “Any observed associations are best explained by residual confounding.” Second, they conduct an observational analysis of nearly 12,000 children from the Twins Early Development Study. They find that breastfed girls, but not boys, have a significant, but very small, increase in IQ at age 2. They also find that the slope of the increase in IQ beyond age 2 is unaffected by whether or not the child was breastfed. They conclude that, while science cannot exclude tiny effects, the evidence for an effect of breastfeeding on IQ is very weak. Most studies show that the effect goes away or rapidly attenuates as adjustments are made for known confounders. These results are consistent with various experimental studies of nutritional supplements in early life, where null results contrast with positive results from social and educational interventions.

— Richard Lilford, CLAHRC WM Director

References:

  1. Victoria CG, et al. Association between breastfeeding and intelligence, educational attainment, and income at 30 years of age: a prospective birth cohort study from Brazil. Lancet Glob Health. 2015; 3(4): e199-205.
  2. von Stumm S & Plomin R. Breastfeeding and IQ Growth from Toddlerhood through Adolescence. PLoS One. 2015. [ePub].
  3. Walfisch A, Sermer C, Cressman A, Koren G. Breast milk and cognitive development – the role of confounders: a systematic review. BMJ Open 2013; 3: e003259.

Molecular Diagnostic Testing, including Whole-Exome Sequencing, in Children with Autism Spectrum Disorder

CLAHRC WM News Blog features articles of generic, rather than specific, interest. The general interest here lies in the use of molecular techniques to unravel the mechanisms of diseases, especially neurological diseases, that are inaccessible to study in other ways.
A study of 258 consecutively ascertained children with ASD was recently reported in JAMA.[1] The incidence of genetic abnormalities was low (about 6%) in ASD children with no morphological abnormalities, but unsurprisingly reached much higher levels (38%) when complex morphological abnormalities were present. To the CLAHRC WM Director this finding suggests that ASD, when not associated with atypical physical features, is seldom caused by embryonic de novo or inherited genetic disorder. But could it be caused by propagation of a clone of neurons with a new mutation derived during the first wave of brain remodelling in utero?[2] [3]

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Tammimies K, Marshall CR, Walker S, et al. Molecular Diagnostic Yield of Chromosomal Microarray Analysis and Whole-Exome Sequencing in Children with Autism Spectrum Disorder. JAMA. 2015; 314(9): 895-903.
  2. Lilford R. An hypothesis on the cause of many chronic neurological conditions, such as schizophrenia and Alzheimer’s disease. January 18 2013.
  3. Lilford R. Biological mechanism of generalised brain disease such as Alzheimer’s disease and schizophrenia. March 1 2013.

Really Important Papers on Child Development

Our CLAHRC has recently conducted an individually randomised trial of the effect of perinatal (before and after birth) support from lay health workers for women at high social risk. The results have been submitted for publication, but in the meantime the BMJ has reported a 2×2 factorial RCT of an integrated early child development intervention, consisting of micronutrient supplementation and weekly stimulation through local women. The study was conducted across 96 communities in Columbia.[1] While the supplementation yielded a null result, the additional psychosocial stimulation produced marked improvements in cognition and language over an 18 month intervention period. The results partly corroborate a similar recent study reported in the Lancet.[2] This study was also a 2×2 factorial design, again of nutrition (including micronutrients) and stimulation. This study involved 80 communities in Pakistan. They replicated the findings regarding stimulation, but also recorded a positive, albeit smaller, cognitive benefits from the nutritional intervention. Babies and toddlers are little learning machines who love to interact, and benefit themselves and others by doing so. The effect of nutrition may be more context dependent.[3] Our CLAHRC is considering conducting an overview, combining studies that examine antenatal and postnatal interventions, or both, and that compare interventions targeted mainly at the mother, versus those where the infant is the primary focus of attention. In the meantime, here are two excellent cluster factorial designs of similar interventions in two different continents, serendipitously published within weeks of one another.

— Richard Lilford, CLAHRC WM Director

References:

  1. Attanasio OP, Fernandez C, Fitzsimons EO, Grantham-McGregor SM, Meghir C, Rubio-Codina M. Using the infrastructure of a conditional cash transfer program to deliver a scalable integrated early child development program in Colombia: cluster randomized controlled trial. BMJ. 2014; 349: g5785.
  2. Yousafzai AK, Rasheed MA, Rizvi A, Armstrong R, Bhutta ZA. Effect of integrated responsive stimulation and nutrition interventions in the Lady Health Worker programme in Pakistan on child development, growth, and health outcomes: a cluster-randomised factorial effectiveness trial. Lancet. 2014; 384: 1282-93.
  3. Black MM & Hurley KM. Investment in early childhood development. Lancet. 2014; 384: 1244-5.

Importance of Talking to Babies

CLAHRC Birmingham and Black Country (the precursor of CLAHRC WM) has studied the effect of perinatal support on mother-child bonding. This work is right on the money according to this year’s meeting of the American Academy for Advancement of Science. It is well known that by the age of four, children born into professional families have heard 30 million more words than those from alternative backgrounds.[1] Differences are apparent as early as 18 months of age and the words need to be spoken directly to the child – television will not do.[2] There are reasons to believe that neurons form more connections when stimulated through speech.[3] [4] Professor Christine MacArthur and Dr Sara Kenyon – main architects of the CLAHRC BBC study – will now follow-up children to see if those in the intervention group have better neuro-cognitive outcomes than those in the control. It would be fascinating to observe the effect of social interventions, such as the one we have implemented, on verbal interactions between parent and child. Our work focusses on early development because it is difficult for education and affirmative action to overcome disadvantages arising in the first years of life.

–Richard Lilford, Director of CLAHRC WM

References:
[1] Hart B, Risley TR. Meaningful Differences in the Everyday Experience of Young American Children. Baltimore, MD: Paul H. Brookes Publishing Co., Inc. 1995
[2] Fernald A, Marchman VA, Weisleder A. SES differences in language processing skill and vocabulary are evident at 18 months. Dev Sci. 2013; 16: 234–48.
[3] Noble K. Socioeconomic Disparities in the Structure of Language Areas in the Developing Brain. AAAS 2014 Annual Meeting. 14 Feb 2014.
[4] The Economist. Child Development: In the Beginning was the Word. The Economist. 22 Feb 2014. pp 67-8.