The pediatrician must play a pivotal role in identifying developmental disability since he is the one who gets uniquely involved in the care of the infant.1–5 Unfortunately, in actual practice, it does not often happen.6–8 The major reason appears to be much-too-much load on the pediatrician in busy settings. And, perhaps, a notion on the part of a substantial proportion of pediatricians that developmental screening is not only time-consuming but also the domain of neurologist/psychiatrist.9–13 How untrue ! In a recent internet study, conducted under the aegis of Pediatric Education and Communication Network (PECN), 72% European, 70% American, and only 20% Indian pediatricians said they were routinely carrying out some form of developmental screening in their general practice. According to Needlman,14 in one large multicity study, physicians identified only 23% of emotional problems and 19% of hyperactivity before other professionals did. Though Down Syndrome and cerebral palsy were detected at 0.6 months and 10.3 months, respectively, mean ages at which mental retardation, speech defects and hearing problems were detected happened to be 34 months, 38 months and 39 months, respectively.
This chapter intends to provide a short-yet-comprehensive account of developmental screening and assessment. Needless to say, in doing so, liberal use has been made of the commendable works of many authorities, including Professor Arnold Gesell (“Developmental Diagnosis”, “Biographies of Child Development”, Bayley (“Manual Growth During the First Three Years”), Knobloch, Pasamanick (“Gessel and Amatruda's Developmental Diagnosis”), Griffiths (“The Abilities of Babies”), Denver, Illingworth (“The Development of the Infant and Young Child”, “Your Child's Development in the First Five Years”, “Basic Developmental Screening”, “Babies and Young Children”, “Some Problems of the Early Years and their Treatment”), intensely involved in the field. Undoubtedly, also has been made the full use of authors' over 3 decades of experience in dealing with thousands of neonates, infants and children as also close observations on our own children (and nephews and nieces) in the form of notes that we had started making right since their births, especially commencing with the first noteworthy experiences that they exhibited.
Before dwelling on the details, let us recall what developmental assessment denotes. Developmental assessment should be considered a 2-step process comprising screening and diagnosis. The first step, screening, should be reserved for picking up children in need of detailed assessment. The second step, diagnosis, should aim at precisely defining the developmental problems as also their significance from the angle of child's biologic, psychologic and social strengths and weaknesses.
Of late, developmental screening is giving way to developmental surveillance. The latter should be considered an ongoing process based on inputs from parents and other multiple sources and detailed longitudinal observations with or without the assistance of screening tests such as DDST. In fact, assessment takes off with the history per se, open-ended provocative questions for ascertaining the temperament and personality of the child and the close family members as also for identifying concerns of parents. The role of previsit questionnaires in this behalf is remarkable. These are very helpful in soliciting concerns and focusing the agenda of the visit, conveying interest of the pediatricians in developmental issues and encouraging parents to express concerns that may have otherwise escaped attention. A direct examination, including office testing (say DDST) is important for documenting abilities.
Charles Darwin was the first to publish a detailed record of child development, including observations on crying, sobbing, laughter and other emotions in “The Expression of the Emotions in Man and Animals” (1872) and “A Biographical Sketch of an Infant” (1877) followed by Shin in 1893 and Shirley in 1931.
Stern and Kuhlman in 1912 gave the concept of intelligence quotient (IQ), the ratio between assessed mental age and actual chronological age.
In early and mid-1990s, Arnold Gessel followed by Knobloch, Pasamanick, Ruth Griffiths and others published norms of development on a large number of children.
In 1967, the famous Denver Developmental Screening test (DDST) was documented. It was based on a sample of 1000 selected children. It assessed development of infants and children (usually up to 3 years) in 4 vital areas, namely gross motor, fine motor adaptive, language and personal social behavior. There were 105 items, some indeed difficult to administer. Moreover, it was not quite appropriate for children with mothers who were not having enough education. In addition, it had less items related to language. As a shortcut, a “short” DDST became available but it had got to be followed up by the full DDST subsequently for dependable results.
In 1981, a major revision, modification and standardization of the original DDST occurred in the form of Denver II which has 125 items instead of 105 and yet takes only 5–7 minutes. Otherplus points of Denver II over DDST include availability of Denver II Screening Manual, availability of Denver II Technical Manual and availability of a video instructional program and proficiency test. Make no mistake that it is only a screening test for identifying children who are not performing in keeping with their ages, irrespective of the reason(s). It undoubtedly does not measure intelligence or developmental quotient. Attempts are on way to produce a short (abbreviated) Denver II needing just 5 minutes for assessment. Details are provided in Chapter XX. At this stage, remember, the major limitation of DDST lies in its wrong use as an IQ test which it indeed is not.
About the same time, Boel tests for visual, auditory and tactile sense emerged on the scene for use in infants aged 7–9 months. In these tests, a red object is employed to attract visual attention, four bells, attached to the tester's fingers, attract auditory attention.
The other development screening tests that appeared on the scene included Brazelton and Dubowitz tests, Gessel DST, Bayley DST, Woodside DST, developmental profile (DP-II), cognitive adaptive test/clinical linguistic auditory milestone scale (CAT/CALMS), early language milestone scale (ELM) and Vineland social maturity scale.
In India, Phatak from Baroda (now rechristened Varoda) adopted the so-called Baroda screening tests from Bayley developmental scale to suit the Indian infants and children, aged 0–36 months. It has 25 test items listed according to child's age. It is primarily meant for use by the child psychologists rather than pediatricians. Domains evaluated are gross motor, fine motor, and cognitive. Administration time is 10 minutes. Sensitivity is 0.66–0.93 while specificity is 0.77–0.94.
Yet another test developed in India (Trivandrum DST) is based on Baroda norms. It has 17 test items and is relevant for age 0–2 years. Domains evaluated are gross motor, fine motor and cognitive. Administrative time is 5 minutes. Validity and specificity are 0.67 and 0.79 respectively.
Developmental screening is important to parents, to obstetricians, to neonatologists and to pediatricians. Let's see how in the following paragraphs.
First thing first! Every parent is eager to know if the child is developing normally, especially if there is history of a miscarriage or stillbirth, mental retardation, physical disability, maternal infection, disease or drug abuse. Developmental screening, is, therefore, an essential prerequisite for developmental assessment and, subsequently, for any corrective intervention.
WHO IS THE BEST FOR DEVELOPMENTAL SCREENING: PEDIATRICIAN OR PSYCHOLOGIST?
As an accepted convention, a pediatrician is supposed to base his developmental screening on detailed history and physical examination with special reference to developmental examination, some investigations and the overall interpretation of the whole spectrum. This is absolutely logical because a large number of factors (prenatal, natal and postnatal) have a significant bearing on child's development. The pediatrician must obtain relevant information in relation to these factors if he is to reach the right conclusion about the developmental quotient (DQ). The pediatrician should be reassuring but only up to a point. In no case should he dismiss parental developmental concerns prematurely in his over-enthusiasm to provide support and advocacy to parents. The probability of premature reassurance becomes most likely when the child has normal motor ability or when he is cute, sweet, alert or sociable. The pediatrician's role should, therefore, be considered “central” in early and fair identification of developmental defects. Once developmental delays are identified, he is also expected to have the full evaluation and provide support to the child and the family to maximize child's potential abilities.
In contradistinction, the psychologist is not much bothered about the history and physical examination and depends, by and large, on the purely objective tests based on scoreable items of behavior. His major goal is a unitary figure or score for assessment. This approach is likely to lead to fallacies.
DEVELOPMENTAL SCREENING AND DEVELOPMENTAL PREDICTION
Despite doubts raised by certain workers about the value of developmental screening, as per the conviction of Professor Illingworth and many other experts, developmental testing in infancy does have a definite predictive value.
Yet, let me put it straight that developmental prediction through screening is not without limitations. Illingworth has eminently listed these as follows:
- We cannot draw a clear-cut dividing line between normal and abnormal.
- We cannot make accurate predictions of child's future intelligence and achievements because these will be profoundly affected by environmental and other factors.
- We cannot eliminate the possibility that he will undergo mental deterioration in future months or years.
- We cannot assess at one solitary examination the extent of the damage that he has suffered or its reversibility if the child has already suffered severe emotional deprivation.
- We cannot be sure that he is slow starter/maturer if he is retarded and has no microcephaly.
- We cannot tell after the neonatal period if we should allow for prematurity or not if he was a low birthweight baby and we do not know the duration of gestation.
- We cannot make a sensible prediction for a fullterm baby at birth or in the first 4 weeks unless there are grossly abnormal signs.
- We cannot rely on diagnosing mild cerebral palsy (CP) or mild mental subnormality in the early weeks of life.
- We cannot really be too sure about the dependability of the abnormal neurologic signs detected in the first few weeks.
- We cannot eliminate infancy the possibility that he will subsequently display specific learning disorders or difficulties of spatial appreciation.
- We cannot translate into figures Gessell's insurance factors, namely the baby's alertness, interest in surroundings, social responsiveness, determination and power of concentration, neither can we score the quality of his vocalization without special equipment.
- We cannot say what he will do with his talents or developmental potential.
- We cannot prove, in any but exceptional cases, that a child's mental or neurologic deficits are due to birth rather than to prenatal causes.
- We cannot normally predict mental superiority.
HARMS AND LIMITATIONS OF THE DEVELOPMENTAL SCREENING
According to one of us (SG), “I had never realized that there indeed was some danger inherent in developmental screening until I came across an absolutely normal child whom, as per the parents, I had designated as abnormal (Cerebral palsy) when he was 5 months of age. Undoubtedly, my wrong diagnosis had caused much anxiety to the parents. That was in the beginning of my career as a junior pediatrician at Snowdon Hospital attached to the HP Medical College (now renamed Indira Gandhi Medical College), Shimla, India, in early 1970s.”
Subsequently, the author has encountered many children diagnosed as “spastic”, “mentally retarded”, “hydrocephalic” though, in fact, there is nothing wrong with them. It is not so easy to visualize how much anxiety can such a mistake cause to vulnerable parents.
Likewise, a missed diagnosis too is undesirable. It becomes a tragedy for the parents when a child labelled as “normal” subsequently turns out to be abnormal.
Table 1.1 lists the abuses to which developmental screening tests may be subjected.
It needs to be emphasized—yes, even at the expense of repetition— that, when in doubt about the real status of the child, it is always wise to re-examine him and, if found necessary, to advise the parents to come for follow-up. But, remember, this must be done without causing worry to parents.
PARENTS' OPINION AS A PRESCREENING DEVELOPMENTAL TEST
Eliciting parents' concerns about child's developmental status is on the threshold of emerging as an important prescreening procedure for detecting developmental delay.13–15 Studies have shown that parents who express concerns about speech, language, fine motor or cognitive skills have children with an 80% chance of failing standardized developmental screening. In a recently-concluded study from Chandigarh, India, it has been demonstrated that parents of delayed children very often do not raise global/cognitive concerns and are more likely to raise social, gross motor, behavior, expressive language and medical concerns (e.g. not growing well, remains sick, not eating). We do agree to the suggestion that “pediatricians should routinely and carefully elicit parents' opinions and concerns which need to be viewed as helpful adjuncts to routine assessment and should be used to make appropriate referrals” (Malhi and Singhi, CHD).
- Algranati P. Effect of developmental status on the approach to physical examination. Pediatr Clin North Am 1998; 45: 1–23.
- Dworkin P. British and American recommendations for developmental monitoring: The role of surveillance. Pediatrics 1989; 84: 1000–1010.
- Frank WE. Perspectives in Child Development, 2nd edn. Smith and Smith, London: 2000
- Frankenburg WK, Dodds J, Archer P, et al. Rhe Denver II: A major revision and restandardization of the Denver developmental screening test. Pediatrics 1992; 89: 91–97.
- Glascoe FP, Dworkin PH. The role of parents in the detection of developmental and behavioral problems. Pediatrics 1995; 95: 829–836.
- Glacoe FP. Altmeier WA, McClean WE. The importance of parents concerns about their child's development. Am J Dis Child 1989' 143: 955–958.
- Glascoe FP. Parents' concerns about children's development: Prescreening technique or screening test. Pediatrics 1997; 99: 522–528.
- Green M. Bright Futures: Guidelines for Health Supervision of Infants, Children and Adolescents. National Center for Education in Maternal and Child Health Arlington: 1994.
- Gupte S. Growth and development, In: Gupte S (ed) The Short Textbook of Pediatrics, 10th edn. Jaypee Brothers New Delhi: 2004:
- Malhi P, Singhi P. Role of parents' evaluation of developmental status in detecting developmental delay in young children. Indian J Pediatr 2002; 39: 2002.
- Illingworth RS. The Development of the Infant and Young Child, 9th edn. Churchill Livingstone, Edinburgh: 1987.
- Illingworth RS. Basic Developmental Screening, 3rd edn. Blackwell, Oxford: 1982.
- Needlman RD. Developmental assessment. In: Behrman RE, Kliegnan RM, Jenson HB (eds) Nelson Textbook of Pediatrics, 16th edn. WB Saunders Philadelphia: 2000: 61–65.
- Squires J, Nickel R, Eisert D. Early detection of developmental problems: Strategies for monitoring young children in practice settings. J Dev Behav Pediatr 1996; 17: 420–427.