A Comparative Review of Developmental Screening Tests

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REFERENCES

1. Saling E. Foetal and Neonatal Hypoxia. London: Edward Arnold; 1966

2. The Oxford Universal Dictionary Illustrated. London: The Caxton Publishing Company Limited; 1967: 1972-1973

180 PEDIATRICS Vol. 88 No. 1 July 1991

Letters

to the Editor

Statements appearing here are those of the writers and do not represent the official position of the

American Academy of Pediatrics, Inc, or its Committees. Comments on any topic, including the

contents of PEDIATRICS, are invited from all members of the profession; those accepted for publication

will not be subject to major editorial revision but generally must be no more than 400 words in length.

The editors reserve the right to publish replies and may solicit responses from authors and others.

Letters must be signed and should be submitted in duplicate, double-spaced, on plain white paper with name and address of author(s) on the letter. Send them to Jerold F. Lucey, MD, Editor, Pediatrics Editorial Office, Medical Center Hospital, Burlington, VT 05401.

A Matter

of Terminology

To the

Editor.-02 “saturation” of hemoglobin has been used as a

noninvasive, continuous measurement, adjunct to Pao2

and PadO2 invasive measurements, in mechanical venti-lation ofthe newborn. It reflects the relationship between oxyhemoglobin and total hemoglobin and is expressed in percent.’ 02 saturation measurement is safe and useful if kept below 90%, the point where the dissociation curve

starts its horizontal alignment.

In medical literature authors invariably use the

expres-sion “02 saturation.” This expression is inaccurate.

The Oxford Universal Dictionary Illustrated2 states:

“Saturate [. . .] (saturat, saturare, [. . .] Chem. To cause (a substance) to combine with or dissolve the utmost possible quantity of another [. . .]. Saturated [. . .] Phys-ics. That has combined with or dissolved the largest proportion of another substance [. . .J.”

Thus, a substance may or not saturate another, a

substance may or may not be saturated by another but,

considering the meaning of the word saturation, it is a

contradiction to speak of percentages of saturation. It would, perhaps, be consistent to use, instead, the term

“02 combination” or any other combination synonym.

J. M. RAMOS DE ALMEIDA

Department of Pediatrics

Maternity Dr. Alfnedo da Costa

1, Rua Viniato 1000 Lisboa, Portugal

A Comparative

Review

of Developmental

Screening

Tests

To the

Editor.-In a recent article entitled “A Comparative Review of Developmental Screening Tests” Glascoe et al focused on an urgent problem: practitioners’ need for guidance in defining approaches and selecting instruments for the developmental screening of infants and young children

in accordance with Public Law 994572 This is one of

the first attempts in the pediatric literature to review and

recommend developmental screening devices. However,

significant problems with the methods of test selection

and evaluation limit one’s ability to draw useful

conclu-sions from this study.

We wish to discuss several concerns with this paper.

1. State of the Art. Developmental screening of infants and toddlers is plagued by two undeniable and related factors: a) the nature of normal development (in which there are widely acceptable variations) and behavior (which is highly state- and situation-dependent resulting in unreliable test performances); and b) the limited pre-dictive validity of all available instruments. Even the Bayley Scales of Infant Development,3 the assessment

instrument most often used to establish concurrent

valid-ity of infant screening measures, does not predict

ade-quately subsequent ability levels for most children.4 Any review of developmental instruments should acknowledge

these issues; yet Glascoe et al did not. In addition, we

have concerns about the author’s premise that “screening

. - . is best conducted with standardized tests”.’471 This

simply is not true, especially for infants and toddlers, for

whom demographic predictors (eg, parent education level,

socioeconomic status) are also important considerations.’ Furthermore, the authors’ interpretation that health care

workers may use screening tests to “not only detect

developmental delays but also determine program

at Viet Nam:AAP Sponsored on September 2, 2020 www.aappublications.org/news

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LETTERS TO THE EDITOR 181

bility” ):)47) is a serious misstatement. Screening is a

process designed to identify children who should be

stud-ied further.’ It is not appropriate to utilize screening data

diagnostically.

2. Selection of Screening Tests. We question the

selec-tion of several of the instruments reviewed in this paper.

According to the National Early Childhood Technical

Assistance System (NEC-TAS)’ an assessment

instru-ment should never be used for any purpose for which it

was not designed. Some instruments reviewed in the

article (eg, Slosson) were not designed as screening

meas-ures. Others would not be practical for the practitioner if

30 to 60 minutes are required for administration. In

addition, the selection of the instruments was not

ex-haustive. Certainly, a list generated by a few individuals

or sources is likely to be idiosyncratic at best and result

in important omissions. Nonrepresentative and outdated

measures were included in the review, whereas other

recently published, nationally standardized scales were

omitted. The authors do not describe in sufficient detail

how the measures were selected, and this omission, as

well as the peculiar mix of scales, introduces the question

of sampling bias. Finally, Public Law 99-457 additionally

targets infants and toddlers. Less than half of the

instru-ments presented included this age group.

3. Diversity of Instruments. Many of the instruments

reviewed in the Glascoe et al article were developed to

assess quite separate developmental domains and age

ranges. For example by the authors own descriptions,

“the Quick Test is actually a measure of receptive

lan-guage in children two years and older,””3’ whereas the

Infant Monitoring System is said to assess five

develop-mental domains in infants younger than 36 months of

age. In addition, the methods used for obtaining the developmental information vary considerably (eg, direct

observation in a structured or semistructured setting vs

parent report only, or both). Further, the inclusion of “IQ

tests” and “school readiness” measures in a review of

developmental screening tests to meet the intent of

Pub-lic Law 99-457, which focuses on identification of young

children in need of further assessment, is confusing and

troublesome. The assumption that such diverse

instru-ments can be compared directly is naive at best.

4. Evaluation Methods. The Glascoe et al article does

not specify clearly how each instrument was evaluated,

and it is particularly vague about the qualifications and

procedures used by the three judges. There is insufficient

information describing how quality ratings (eg, excellent,

good, fair) were assigned or how disagreements among

judges were resolved. For example, “validity” was rated

along six dimensions, by three judges; yet the authors do

not explain how a single summary rating was determined.

For the majority of instruments, it is not clear whether

evaluation of psychometric properties was based on kit

materials alone or on independent, external sources as

well. Developers and marketers of testing materials

in-dude information that supports the product. As such,

this information is not necessarily fully objective, may

present conflict of interest issues, and thus is an

inappro-priate basis of comparison. There is extensive peer-re-viewed literature regarding instrument reliability, con-current validity and cultural relevance across groups of

children for several developmental screening tests. Yet,

the authors did not acknowledge the potential problems

inherent in directly comparing instruments that are at varying stages of psychometric study. Finally, we

ques-tion whether the opinions generated by one person

ad-ministering one test one time, as presented in this article,

are generalizable and widely useful.

S. Presentation of Information. The choice to

summa-nize the “findings” of this article in a table format is very

troublesome. Given our concerns regarding the method and thoroughness of test selection and evaluation, such a table is not justified by the “data.” The table format

implies that all tests are equally comparable, and thus, is

at great risk for misuse. It suggests to practitioners that

they can select a screening device from the table with

ease and confidence. In addition, the use of a table

summary conveys the impression of equivalence across

the rated dimensions (eg, test standardization features,

interpretation guidelines). In fact, most testing experts would assert that some standard of technical adequacy

must be achieved before a scale should even be examined

on other dimensions. Of particular relevance to screening

tests are the dimensions of sensitivity and specificity,

which are absent in the majority of the scales reviewed.

Furthermore, there is an implicit naivete in the authors’

consideration of technical adequacy. For example, their

assertion that “standardization is adequate except that

the normative sample includes only families in the

North-east””#{176} is troublesome. Finally, because the article

ap-pears in a section entitled “Consumer Reports,” the

reader may be misled into interpreting results as an

endorsement of certain screening procedures by

Pediat-rics.

In summary, the one-dimensional analysis of child-hood screening presented in the article oversimplifies what should be a more sophisticated evaluation process.

The method of grouping the tests without acknowledging

important differences in test type and the ages of the

children for whom the tests were developed may, in fact,

promote invalid uses of the measures. As a result, this article does not advance our ability to identify young

children who have or are at risk for developmental

prob-lems or handicapping conditions.

We believe that if the goals of Public Law 99-457 are

to be met, a far more comprehensive approach to

screen-ing than entertained by this article is required by

pedi-atric care providers. The approach should include consid-erations of historical (biologic) risk factors, parent per-ceptions, environmental contexts, cultural factors, and

social support, in conjunction with repeated monitoring

of the developmental progress of children with screening procedures that best tap the skills and concerns appro-priate for a given age range. Yet, there are no current

guidelines for the practitioner regarding how best to

approach such a screening process. We hope that the

shortcomings of the article by Glascoe et al and the

serious potential for its misuse will spur a coordinated,

scientifically based effort by national leaders in areas of

pediatrics, family medicine, psychology, education, and speech and language to recommend state-of-the-art ap-proaches to screening based on updated research, peer review, and national experience. Although the consensus

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182 LETTERS TO THE EDITOR

would likely be that there is currently no one “best screening measure,” there is a wealth of knowledge and

experience with which to consider this issue. The need

for further attention to the area of the developmental screening of young children is clear.

BARBARA FELT, MD Department of Pediatrics

Rainbow and Childrens Hospital

Case Western Reserve University School of Medicine

2074 Abington Road

Cleveland, Ohio 44106

TERRY STANCIN, PHD

Department of Pediatrics MetroHealth Medical Center

Case Western Reserve University School of

Medicine

Chair of the Behavioral Pediatrics Consor-tium of Northeastern Ohio

3395 Scranton Road

Cleveland, Ohio 44109

B. Felt and T. Stancin represent The Be-havioral Pediatrics Consortium of

North-eastern Ohio

Contributers from the Behavioral Pediatrics Consortium of Northeastern Ohio:

Geongette Constantinou, PhD, Children’s Hospital Medical Center of Akron, North-eastern Ohio Universities College of Med-icine, Akron, OH

Daniel Coury, MD, Columbus Children’s Hospital, Ohio State University,

Colum-bus, OH

Caren Cunningham, PhD, Mt. Sinai Hos-pita!, Cleveland, OH

Dennis Drotar, PhD, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH John Dubey, MD, Children’s Medical

Cen-ten, Wright State University, Dayton, OH Dianne Ellis, MD, Rainbow Babies and

Children’s Hospital, Case Western

Re-serve University School of Medicine, Cleveland, OH

Jane Ho!an, MD, Blick Clinic, Akron, OH

Nancy Klein, PhD, Cleveland State Univer-sity, Cleveland, OH

Suzanne Lesure, PhD, Children’s Hospital Medical Center of Akron, Northeastern Ohio Universities College of Medicine, Akron, OH

Betsy Lozoff, MD, Rainbow Babies and Children’s Hospital, Case Western

Re-serve University School of Medicine, Cleveland, OH

Karen Olness, MD, Rainbow Babies and Children’s Hospital, Case Western Re-serve University School of Medicine, Cleveland, OH

Lynne Singer, PhD, Rainbow Babies and Children’s Hospital, Case Western Re-serve University School of Medicine,

Cleveland, OH

Jean Smelken, MD, Rainbow Babies and

Children’s Hospital, Case Western Re-serve University School of Medicine,

Cleveland, OH

Michael Stern, D, Tod Babies and

Chil-dren’s Hospital, Youngstown, OH Lynne Sturm, PhD, MetroHealth Medical

Center, Case Western Reserve University

School of Medicine, Cleveland, OH Cathy Telznow, PhD, Cuyahoga Special

Ed-ucation Service Center, Cleveland, OH

Shelley Walker, ACSW, LISW, Children’s

Hospital Medical Center, Akron, OH Reeves Warm, MD, Hanna Pavilion, Case

Western Reserve University School of Medicine, Cleveland, OH

REFERENCES

1. Glascoe FP, Martin ED, Humphrey S. A comparative review of developmental screening tests. Pediatrics.

1990;86:547-554

2. DeGraw C, Edell D, Ellers B, et al. Public Law 99-457: new

opportunities to serve young children with special needs. J Pediatr. 1988;113:971-974

3. Bayley N. Bayley Scales oflnfant Development. San Antonio,

TX: Psychological Corp, 1969

4. Molfese VJ. Perinatal risk and infant development: assess-ment and prediction. New York: Guilford Press; 1989 5. Meisels SJ, Provence S. Screening and assessment:

guide-lines for identifying young disabled and developmentally vul-nerable children and their families. Washington, DC: Na-tional Center for Clinical Infant Programs; 1989

In

Reply.-Drs Felt and Stancin advocate admirably for a

corn-prehensive assessment process which includes a broad range of factors (eg, environments, parents’ perceptions, socioeconomic status, parental mental health, medical history, etc). Although this is worthwhile, the purpose of our article was to “help pediatricians select among the bewildering array of screening tests as well as evaluate

the strengths and weaknesses of each. . To that

end, we evoked standards of excellence for educational and psychologic tests used by the American Psychological Association and by researchers in developmental

screen-ing.’6 In the absence of a governmental regulatory agency

which ensures that quality measures and quality

meas-ures alone are available to consumers, such standards

offer a viable and worthwhile means for comparing tests and selecting those which most accurately detect children with developmental problems.

We agree with Drs Felt and Stancin that one clear

omission in the standards we proffer, and indeed in tests

themselves, is the assessment of environmental charac-teristics which can influence children’s development

strongly, either adversely or positively. Another standard

at issue is that ofpredictive validity. Within certain limits (eg, Bayley scores less than SO), predicting long-term developmental outcome remains an elusive goal,

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1991;88;180

Pediatrics

BARBARA FELT and TERRY STANCIN