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• Re: Is it fallacious to predict future outcomes using developmental tests alone?
  Frances M Cowan
  Published on: 22 March 2016
• Is it fallacious to predict future outcomes using developmental tests alone?
  Srinivas S Gada
  Published on: 22 March 2016

• Published on: 22 March 2016

  Re: Is it fallacious to predict future outcomes using developmental tests alone?

  • Frances M Cowan, Neonatal neurologist
  • Other Contributors:
    • Anna L. Barnett, Eugenio Mercuri, Leena Haataja and Sheila E. Henderson

  Dear Editor,

  We thank Drs Gada and Kanumakala for their letter [1]. We agree that prediction of future outcome using developmental tests alone is difficult. However, despite these difficulties we have shown good sensitivity and positive predictive value of an abnormal score on the Griffiths scales for an abnormal outcome at 5-6 years [2]. Whilst we recognise the influence of genetic, socio-economic factors and env...

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  Dear Editor,

  We thank Drs Gada and Kanumakala for their letter [1]. We agree that prediction of future outcome using developmental tests alone is difficult. However, despite these difficulties we have shown good sensitivity and positive predictive value of an abnormal score on the Griffiths scales for an abnormal outcome at 5-6 years [2]. Whilst we recognise the influence of genetic, socio-economic factors and environment on development, we consider this is probably less for the group we have studied than for a low risk full term population, preterm groups or normal controls.

  We agree that developmental tests are not a substitute for a full assessment. All the children in our study had a full assessment on many occasions – but that was not the subject of this paper. Furthermore, in centres with fewer resources than we have available to us, assessments are likely to be quite limited.

  Inevitably, developmental tests appropriate at different developmental ages have different items, constructions, standardisation etc. The purpose of our study was not to compare the results of two tests at the same age but to examine the value of an early assessment using the Griffiths in this high risk group in predicting outcome at early school age.

  We agree that it is highly likely that children with difficulties at younger ages will have persisting if not greater difficulties later. Although there are many studies making this suggestion, there are few data in the literature specifically following up children with neonatal encephalopathy, of likely hypoxic-ischaemic origin, who were thought normal at 1 and 2 years.

  We are pleased that you support our view, namely that the children within the clinical grouping we describe who are found normal at 2 years did warrant continued surveillance.

  References

  (1). Gada S, Kanumakala S. Is it fallacious to predict future outcomes using developmental tests alone? Arch Dis Child 2004 23 July 2004 Letter

  (2). Barnett AL, Guzzetta A, Mercuri E et al. Can the Griffiths scales predict neuromotor and perceptual-motor impairment in term infants with neonatal encephalopathy? Arch Dis Child 2004;89(7):637-43.

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  Conflict of Interest:
  None declared.

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• Published on: 22 March 2016

  Is it fallacious to predict future outcomes using developmental tests alone?

  • Srinivas S Gada, Specialist Registrar Paediatrics
  • Other Contributors:
    • Dr.Shankar Kanumakala, Consultant Paediatrician, Royal Alexandra Hospital for sick children, Brighton BN1 3JN

  Dear editor,

  We read the article by Barnett et al with interest[1]. We believe prediction of future outcome using developmental tests alone is difficult, and can be erroneous[2]. for the following reasons. Firstly, development is a result of complex and dynamic on-going interaction between genetic potential, pre/peri/post natal variables, socio-economic and environmental factors[2,3]. Secondly, developmental tes...

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  Dear editor,

  We read the article by Barnett et al with interest[1]. We believe prediction of future outcome using developmental tests alone is difficult, and can be erroneous[2]. for the following reasons. Firstly, development is a result of complex and dynamic on-going interaction between genetic potential, pre/peri/post natal variables, socio-economic and environmental factors[2,3]. Secondly, developmental tests, like any other diagnostic test, can only provide a snapshot of this evolving process. Thirdly, developmental tests should not substitute but supplement the ‘full assessment’ which includes history, examination (including neurological examination), careful observations and follow-up[2,3]. Over-reliance on developmental tests alone can be deceiving. ‘Full assessment’ would provide better prediction and could have picked up the ‘missing hemiplegias’ as reported[1].

  Moreover comparison between Griffiths scales and other test scores are prone to misinterpretation[3,4], especially when the tests were administered at different ages[1]. This is because the scales differ considerably from one another with regard to selection of test items, test construction, standardisation and inter-rater variability, etc. Results would have been valid had authors used Griffiths scales again at school age, instead they used a cluster of tests that were not used before[5]. The study has attempted to correlate early Griffiths scores with other tests at school age and authors agree that although the results are statistically significant they are of little practical significance[1].

  Furthermore it is known that the incidence of minor neurological dysfunction increases with age[6]. As the child is challenged by more complex skill acquisition with increasing age, the possibility of recognising neurological dysfunction increases. Hence Griffiths Scales[7], like several other developmental tests (Denver Developmental Screening Test[8], Bayley Scales of Infant Development[9] etc.,) have identified neuromotor dysfunction at school age in children who were ‘apparently normal’ at 2 years of age. This study demonstrates the above phenomenon and does not provide clear evidence regarding predictability of Griffiths scales.

  Finally, infants with neonatal encephalopathy are at significantly high-risk of death, serious disability and later neuromotor dysfunction[1]. The authors rightly point out that failure to identify such children would lead to missed opportunities for early intervention. Accordingly, continued surveillance of such ‘high-risk’ children is important. Therefore the rationalising claim of ‘effective use of limited resources’ in follow-up of such children is questionable.

  References

  (1). Barnett AL, Guzzetta A, Mercuri E et al. Can the Griffiths scales predict neuromotor and perceptual-motor impairment in term infants with neonatal encephalopathy? Arch Dis Child 2004;89(7):637-43.

  (2). Illingworth RS. The development of infant and young child Normal and Abnormal, 9th edn. London: Churchill Livingstone, 1987.

  (3). Griffiths R.The abilities of babies. High Wycombe, UK: The Test Agency 1986.

  (4). Ivens J, Martin N. A common metric for the Griffiths scales. Arch Dis Child 2002;87(2):109-10.

  (5). Sackett DL, Straus SE, Richardson WS et al. Evidence-Based Medicine. How to Practise and Teach EBM. London: Churchill Livingstone, 2000.

  (6). Goyen TA, Lui K. Longitudinal motor development of ‘apparently normal’ high-risk infants at 18 months, 3 and 5 years. Early Hum Dev 2002;70:103- 15.

  (7). Majnemer A, Rosenblatt B, Riley P. Predicting outcome in high-risk newborns with a neonatal neurobehavioural assessment. Am J Occup Ther 1994;48(8):723-32.

  (8). Greer S, Bauchner H, Zuckerman B. The Denver Developmental Screening Test: how good is its predictive validity? Dev Med Child Neurol 1989;31(6):774-81.

  (9). Crowe TK, Deitz JC, Bennett FC. The relationship between the Bayley Scales of Infant Development and preschool gross motor and cognitive performance. Am J Occup Ther 1987;41(6):374-8.

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  Conflict of Interest:
  None declared.

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