Developmental Screening—Expecting the Impossible?

(1)

REFERENCES

1. Light RJ: Accumulating evidence: Using meta-analysis to carry out research reviews in pediatrics. Pediatrics

1986;78:1145-1147

2. Ottenbacher KJ, Petersen P: Quantitative reviewing of med-ical literature: An approach to synthesizing research results in clinical pediatrics. Chin Pediatr 1983;23:423-427

3. Chalmers I, Hetherington, J, Enkin M, et al: Overviews

(meta-analyses) of randomized controlled trials to assess the

effects of care during pregnancy and childbirth, in Enkin

MW, Keirse MJNC, Chalmers I (eds): Effective Care in

Pregnancy and Childbirth. Oxford, England, Oxford

Univer-sity Press, 1989, in press

4. Thacker SB: Mets-analysis: A quantitative approach to research integration. JAMA 1988;259:1685-1689

5. Sacks HS, Berrier J, Reitman D, et al: Meta-analyses of

randomized controlled trials. N Engh J Med

1987;316:450-455

6. L’Abbe KA, Detsky AS, Orourke K: Meta-analysis in clinical research. Ann intern Med 1987;107:224-233

7. Yusuf 5, Simon R, Ellenberg S (eds): Proceedings of Meth-odologic Issues in Overviews of Randomized Clinical Trials.

Stat Med 1987;6:217-409

8. Muirow CD: The medical review article: State of the science.

Ann Intern Med 1987;106:485-488

9. Oxman AD, Guyatt GH: Guidelines for reading literature

reviews. Can Med Assoc J 1988;138:697-703

10. Haynes RB, McKibbon KA, Fitzgerald D, et a!: How to keep up with the medical literature: IV. Using the literature to solve clinical problems. Ann intern Med 1986;105:636-640 11. Haynes RB, McKibbon KA, Fitzgerald D, et al: How to keep

up with the medical literature: VI. How to store and retrieve articles worth keeping. Ann intern Med 1986;105:978-984 12. Haynes RB, McKibbon KA, Fitzgerald D, et al: How to keep

up with the medical literature: V. Access by personal

com-puter to the medical literature. Ann intern Med 1986;

105:810-824

13. Bernstein F: The retrieval of randomized clinical trials in

liver diseases from the medical literature: Manual versus

MEDLARS searches. Controlled Chin Trials 1988;9:23-31 14. Poynard T, Conn HO: The retrieval of randomized clinical

trials in liver disease from the medical literature. Controlled Chin Trials 1985;6:271-279

15. Dickersin K, Hewitt P, Mutch L, et al: Perusing the Liter-ature: Comparison of MEDLINE searching with a perinatal trials database. Controlled Chin Trials 1985;6:306-317

16. Gotzsche PC: Reference bias in reports of drug trials. Br

Med J 1987;295:654-656

17. Glass GV, McGaw B, Smith ML: Meta-Analysis in Social

Research. Beverley Hills, CA, Sage Publications, 1981, pp 18-20

.18. Dickersin K, Chan 5, Chalmers TC, et al: Publication bias and clinical trials. Controlled Chin TriaLs 1987;8:343-353 19. Simes RI: Confronting publication bias: A cohort design for

meta-analysis. Stat Med 1987;6:11-29

20. Williamson JW, Goldschmidt PG, Colton T: The quality of

medical literature: An analysis of validation assessments, in

Bailar JC, Mosteller F (eds): Medical Uses of Statistics.

Waltham, MA, New England Journal of Medicine Books,

1986, pp 370-391

21. Sackett DL, Haynes RB, Tugwell P: Clinical Epidemiohogy:

A Basic Science for ClinicalMedicine. Boston, Little, Brown

& Co, 1985

22. Canadian Task Force on the Periodic Health Examination:

The periodic health examination. Can Med Assoc J 1979;

121:3-11

23. Lawrence RS, Mickalide AD: Preventive services in clinical practice: Designing the periodic health examination. JAMA 1987;257:2205-2207

24. Sackett DL: Rules ofevidence and clinical recommendations

on the use of antithrombotic agents. Chest 1986;89:2s-3s

25. Chalmers TC, Smith H, Blackburn B, et al: A method for assessing the quality of a randomized control trial. Con-traIled Chin Trials 1981;2:31-49

26. Feinstein AR, Horwitz RI: Double standards, scientific methods, and epidemiologic research. N Engb J Med 1982;

307:1611-1617

27. Horwitz RI, Feinstein AR: Methodologic standards and

con-tradictory results in case-control research. Am J Med 1979;

66:556-564

28. Horwitz RI: Complexity and contradiction in clinical trial research. Am J Med 1987;82:498-510

29. Freiman JA, Chalmers TC, Smith H Jr, et a!: The impor-tance ofbeta, the type IIerror, and sample size in the design

and interpretation ofthe randomized controlled trial: Survey

of 71 “negative” trials, in Bailar JC, Mosteller F (ads):

Medical Uses of Statistics. Waltham, MA, New England

Journal of Medicine Books, 1986, pp 289-304

30. Cooper HM, Rosenthal R: Statistical versus traditional

pro-cedures for summarizing research fmdings. Psychoh Bull

1980;124:711-718

31. Hart H: Critical reviews: The editor’s point ofview. J Chem

Doe 1968;8:241-244

Developmental

Screening-Expecting

the Impossible?

In this issue of Pediatrics, Meisels’ addresses a topic that has received considerable attention within the child development literature-the valid-ity of the Denver Developmental Screening Test (DDST). The author summarizes data from 13 studies to document the limited sensitivity of the test. However, several of the studies cited by Mei-sels are themselves weakened by methodologic problems. For example, in four of the so-called replication studies, applications were actually ex-amined for which the DDST was not originally designed, such as identifying developmental delay among biologically vulnerable infants,2’3 screening for speech and language problems,4 and identifying children with moderate to severe delays.5 Although studies of such applications are important, they should not serve as the basis for conclusions re-garding the validity of the DDST as a screening

test for the general population of infants and

chil-dren. Whether the pooling of results from studies with methodologic shortcomings strengthens the significance of findings is questionable.

Other assertions raised by Meisels also deserve close scrutiny. A recommendation for the use of alternative developmental screening tests is not

supported by sufficient data. The DDST, as the

most widely used developmental screening test in the world, has been subjected to considerable

analy-sis, yet the alternative tests suggested by Meisels

(2)

620 PEDIATRICS Vol. 83 No. 4 April 1989 have received limited critical evaluation. Also, al-though some evidence does exist to at least suggest that early intervention may be worthwhile for chil-dren with the types of developmental problems that might be identified through screening, there is a clear need for further research to substantiate claims of benefits and cost-effectiveness.’#{176}

Despite these shortcomings, Meisels’ conclusion that the DDST has low test sensitivity is justified. A recent critical review of the effectiveness of select strategies to promote children’s health performed by the US Congress Office of Technology Assess-ment similarly concluded that use of the DDST could not be recommended scientifically.” Fnankenbung’2 himself acknowledged the need for further studies to validate the DDST. In calling for the revising and nestandandizing of developmental screening tests, Meisels implies that tests with more favorable psychometric properties can be designed. However, there exists considerable evidence to sug-gest that problems with the validity of the DDST are not specific to this instrument, but rather ge-nenic to developmental screening tests, and that the successful early identification of developmental problems depends on the implementation of alter-native processes of developmental monitoring.

IS DEVELOPMENTAL SCREENING

APPROPRIATE?

Developmental screening refers to the process of testing whole populations of children to identify those at high risk for significant, unsuspected de-viations from 13.14 Such screening typically involves the application of rapidly administered

tests at various set ages. The goal of screening is to

detect children who are at high risk for develop-mental delay who would not otherwise be identified. The majority of severe developmental impairments (eg, moderate to severe mental retardation, cerebral palsy, muscular dystrophy, autism) are identified by means other than screening: parents may be suspicious of a problem and raise concerns with the health care provider; abnormalities may be detected during routine examinations during infancy and early childhood; delays may be observed during the planned follow-up of infants deemed biologically

vulnerable because of peninatal events, family

his-tory, etc; or problems may be recognized during the assessment of unrelated illness or injury.’’8 Be-cause, by definition, screening is concerned with the identification of unsuspected problems, such severe and relatively obvious impairments as are

otherwise detected are not usually the targets of

developmental screening programs. Rather screen-ing is most often concerned with the identification of children at risk for more subtle developmental

problems that would otherwise elude early detection such as mild mental retardation, speech and lan-guage delays, learning disabilities, and clumsiness.

Developmental screening tests are evaluated by determining the extent to which they fulfill well-accepted criteria for screening procedures. Tests should be acceptable, simple, economical, appropni-ate, reliable, and valid.’9 There exist equally well-recognized criteria by which conditions are judged appropriate for the screening process,’4”9’2#{176} yet the extent to which more subtle developmental prob-lems such as mild mental retardation, speech and language delays, and learning disabilities fulfill such criteria has received limited emphasis. Al-though such problems do meet certain of these

criteria (such as prevalence and morbidity), they

fail to satisfy other requirements. In particular, diagnostic tests do not uniformly enable affected individuals to be distinguished from nonaffected or borderline cases. The limitations of psychometric testing during infancy in identifying mild mental retardation have been well documented.2’ Extensive school readiness test batteries have only modest predictive validity for school performance and learning disabilities.22

Given the difficulties inherent in the early iden-tification of developmental problems, the modest sensitivity of screening tests reported in various studies is not surprising. The failure of research to validate the effectiveness and benefits of develop-mental screening has resulted in a growing skepti-cism among some experts in child health toward the routine administration of developmental tests. For example, the British Joint Working Party on Child Health Surveillance, a committee charged with issuing national recommendations for preven-tive child health care, recently concluded that no

formal program of developmental screening should

be recommended and the performance of routine developmental testing should be discouraged.’7

DEVELOPMENTAL SURVEILLANCE

In Western Europe and especially Great Britain, concerns for the effectiveness of routinely admin-istered developmental screening tests have led to an increasing emphasis on the process of develop-mental surveillance.’7’23 Developmental surveil-lance, although a time-honored activity, is a newer concept than screening. Surveillance is a flexible, continuous process that is broader in scope than screening, whereby knowledgeable professionals perform skilled observations of children throughout all encounters during child health care.24’25 Surveil-lance encompasses all primary care activities re-lated to the monitoring of the development of chil-dren. It includes obtaining a relevant

at Viet Nam:AAP Sponsored on September 7, 2020

www.aappublications.org/news

(3)

mental history, making accurate and informative observations of children, and eliciting and attend-ing to parental concerns. Emphasis is placed on monitoring development within the context of the child’s overall well-being, rather than viewing de-velopment in isolation during a testing session. Surveillance also includes activities designed to promote development, such as the sharing of infon-mation with parents.23

Developmental surveillance does not necessarily exclude the use of developmental screening tests.

Tests such as the DDST may, depending on the

health professional’s experience, knowledge, and confidence, serve as valuable aids to memory, con-tribute to the health provider’s acquisition of knowledge, focus attention on the child’s develop-mental status during a visit, encourage parents to raise concerns on questions, and help validate the provider’s concerns for a child or assist in reassun-ing parents that a child is nonmal.”6”9 Screening

tests are but one strategy whereby the health

professional may perform skilled observation of children.

IMPLICATIONS

Few pediatricians would base their decisions re-garding referrals for developmental assessment on the results of an isolated screening test.26 Rather, current clinical practice is fan more compatible with the process of surveillance, as are the most recent recommendations for developmental monitoring of the American Academy of Pediatrics Committee on Practice and Ambulatory Medicine.27,27a For the pediatric health care provider, performing inform-ative longitudinal observations of children’s devel-opment and behavior and eliciting parents’

impres-sions and concerns require considerable skills and

knowledge. In the past, pediatric training in this area has clearly been inadequate.28 Hopefully, the design and implementation of new curricula will offset past inadequacies.29

For community-based mass screening programs,

results from developmental screening tests should

not be used in isolation to identify children in need

of assessment. Rather, if such screening is to be performed, findings must be integrated with the opinions and concerns of parents and child-cane professionals, including pediatric providers, day-cane staff, preschool teachers, and the like. The validity of screening tests may be improved if the clinical impressions of health professionals are con-sidered when interpreting test results.2 Both parent and preschool teacher opinions are of value in iden-tifying children who are at risk for school-related learning and behavior problems.30’3’ Although such

integration is costly to perform and requires

con-sidenable administrative support, exemplary models of community surveillance programs do exist.32

The validity of developmental surveillance must be examined through large-scale, population-based

studies. The British child health care system, with

its shift in emphasis from screening to surveillance

and its regional organization of health care delivery,

is particularly well suited to such research. We

should observe the results of such studies with great interest. In the meanwhile, despite problems inher-ent to the screening process, the search for im-proved developmental screening tests should not be abandoned. Rather, future research should examine the value of such instruments, not when used in isolation, but rather within the context of active surveillance. Tests such as the DDST may better withstand careful scrutiny if we do not expect of them the impossible.

REFERENCES

PAUL H. DWORKIN, MD Department of Pediatrics

University of Connecticut Health Center Farmington, CT

and

Community Health Offices Radcliffe Infirmary

Oxford, England

1. Meisels SJ: Can developmental screening tests identify chil-dren who are developmentally at-risk? Pediatrics 1989; 83:578-585

2. Sciarillo WG, Brown MM, Robinson NM, et al: Effective-ness of the Denver Developmental Screening Test with biologically vulnerable infants. J Dev Behau Pediatr 1986; 7:77-83

3. Blackman JA, Lindgren 5, Hem H, et al: Long-term sur-veillance of high-risk children. Am J Dis Child 1987; 141:1293-1299

4. Borowitz KC, Glascoe JP: Sensitivity of the Denver Devel-opmental Screening Test in speech and language screening.

Pediatrics1986;78:1075-1078

5. Meisels SJ, Margollis LH: Is the early and periodic screen-ing, diagnosis, and treatment program effective with devel-opmentally disabled children? Pediatrics 1988;81:262-271

6. Bricker D: The effectiveness of early intervention with

handicapped and medically at risk infants, in Frank M (ed):

infant intervention Programs. New York, Haworth Press, 1985, pp 51-65

7. Darlington R, Royee J, Snipper A, et al: Preschool programs

and late school competence of children from low-income

families. Science 1980;208:202-208

8. Shonkoff JP, Hauser-Cram P: Early intervention for

dis-abled infants and their families: A quantitative analysis.

Pediatrics 1987;80:650-658

9. Simeonsson RI, Cooper DM, Schemer AP: A review and

analysis of the effectiveness of early intervention programs. Pediatrics 1982;69:635-641

10. Bronfenbrenner U: is Early intervention Effective? US De-partment of Health, Education, and Welfare, Office of Child

Development, publication No. (OHD) 74-25. Government

(4)

622 PEDIATRICS Vol. 83 No. 4 April 1989

11. Healthy Children: Investing in the Future. US Congress,

Office of Technology Assessment publication No.

OTA-H-345. Government Printing Office, 1988

12. Frankenburg WK: Psychosocial screening, letter. Pediatrics

1987;80:302

13. Commission on Chronic Illness: Chronic illness in the United

States. Cambridge, MA, Harvard University Press, vol 1,

1957

14. Whitby LG: Screening for disease: Definitions and criteria.

Lancet 1974;11:819-821

15. Baird G, Hall DMB: Developmental paediatrics in primary

care: What should we teach? Br Med J 1985;291:583-586

16. Casey P, Sharp M, Loda F: Child-health supervision for

children under 2 years of age: A review of its content and

effectiveness. J Pediatr 1979;95:1-9

17. Hall DMB, Macfarlane JA (ad): Health for All Children.

Report of the Joint Working Party on Child Health

Surveib-lance. Oxford, Oxford University Press, 1989

18. Bolden KJ: Developmental screening clinics are a luxury.

Proc R Soc Med 1976;69:385-386

19. Frankenburg WK: Pediatric screening. Adv Pediatr

1973;20:149-175

20. Jenkins 5: The functions of child health clinics, in Macfar-lane JA (ed): Progress in Child Health. Edinburgh, Churchill Livingstone, 1984, vol 1, pp 199-212

21. McCall RB: The development of intellectual functioning in

infancy and the prediction of later IQ, in Osofsky JD (ad):

Handbook of Infant Development. New York, John Wiley &

Sons, 1979, pp 707-741

22. Dworkin PH: Educational readiness. Pediatrician

1986;13:62-69

23. European Health Committee: Health: Child Health Surveib-lance. Strassbourg, France, Council of Europe, Publications Section, 1985

24. Editorial: Developmental surveillance. Lancet 1986;1:950-951

25. Hutchison T, Nicoll A: Developmental screening and sur-veillance. Br J Hosp Med 1988;39:22-29

26. Shonkoff JP, Dworkin PH, Leviton A, et al: Primary care

approaches to developmental disabilities. Pediatrics

1979;64:506-514

27. American Academy of Pediatrics, Committee on Practice

and Ambulatory Medicine: Recommendations for

preven-tive pediatric health care. Pediatrics 1988;81:466

27a.Dworkin PH: British and American recommendations for

developmental monitoring-The role of surveillance.

Pedi-atrics, in press, 1989

28. Dworkin PH, Shonkoff JP, Leviton A, et al: Training in developmental pediatrics. How practitioners perceive the gap. Am J Dis Child 1979;133:709-712

29. Bennett FC, Guralnick MJ, Richardson HB, et al: Teaching developmental pediatrics to pediatric residents: Effective-ness of a structured curriculum. Pediatrics 1984;74:514-522

30. Ferinden WE, Jacobson 5: Early identification of learning

disabilities. J Learn Dis 1970;3:589-593

31. Oberklaid F, Dworkin PH, Levine MD: Developmental-behavioral dysfunction in preschool children. Descriptive analysis of a pediatric consultative model. Am J Dis Child 1979;133:1126-1131

32. Levine MD, Wolman R, Oberklaid F, et al: The longitudinal study of findings in childhood: Analysis of an

interdiscipli-nary process. Am J Dis Child 1982;136:303-309

IS ANYONE PAYING ATrENTION?

Look at the kids on every street corner, in the arcades, huddled beneath movie marquees. Then ask yourself how long it will be before New York-before America-ends up with millions of abandoned children like India on South America.

McDowell E: The Lost World. New York, St Martins, 1988.

Submitted by Student

(5)

1989;83;619

Pediatrics

PAUL H. DWORKIN

Expecting the Impossible?

−−