NECTAC Webinar Series on Early Identification and Part C EligibilitySession 2: A Rigorous Definition of Developmental DelayMarch 10, 2010

Steven Rosenberg, Ph.D.University of Colorado Denver

Duan Zhang, Ph.D.University of Denver

Issues

• Nationally only a small proportion of the children who are likely to be eligible for Part C services receive early intervention.

• Eligibility definitions, used by states and

jurisdictions, make many more children likely to be Part C eligible than the system serves.

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More Children are Likely to be Part C Eligible than are Served

Eligibility More than 12 percent of the nation’s children who are under 3 years of age are likely to be Part C eligible.

Underenrollment Only about 10 percent of these presumptively Part C eligible children received early intervention services.

Rosenberg, S., Zhang, D. & Robinson, C. (2008). Prevalence of developmental delays and participation in early intervention services for young children. Pediatrics, 121, e1503–e1509.

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Problems with Making Far More Children Eligible than are Served

• States may meet their targeted percentage of children served without having to create effective child find procedures.

• States may miss children who may have a greater need for early intervention than those who are enrolled.

Racial Disparity

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African-American children are half as likely to receive early intervention as white peers.(Rosenberg, Zhang & Robinson, 2008).

Task

Understanding the causes for the large numbers of presumptively eligible infants and toddlers who do not receive Part C services should begin with an examination of how Part C eligibility is defined.

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Definitional Problems

State Part C eligibility definitions are part of the problem:

• Many eligibility definitions make more children likely to be Part C eligible than the system intends to serve.

• Inaccuracies and contradictions are often built into eligibility definitions.

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How Do State Definitions Make Children Part C Eligible?

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Standard deviations are used to establish eligibility.

http://www.comfsm.fm/~dleeling/statistics/notes06.html

Standard deviations used in eligibility definitions assume a normal curve.

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Standard Deviations are Used in Part C Eligibility Definitions

Standard deviations are directly related to the number of eligible children ---

• 2 standard deviations expect about 2% of children for each developmental domain;

• 1.5 standard deviations expect about 7% of children for each domain;

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Assessing for Delays in Multiple Areas Increases Rates of Eligibility

For an eligibility criterion of 2.0 SD below the mean in one domain* assessing with:

• Mental subscale => 2.1% eligible.• Motor subscale => 2.4% eligible. • Mental or Motor subscales => 3.6% eligible.

*Bayley Research Short Form used for ECLS-B 9 month assessments

How Do State Definitions Make Children Part C Eligible?

Developmental Age (DA) Scores

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• Developmental age scores are also used to establish eligibility.

• Developmental age is an estimate of the average age that children can accomplish certain tasks.

Developmental Age Scores

Norm or Criterion Referenced Tests

• DA scores obtained on norm referenced tests represent the average chronological age of the children who obtained a specific raw score.

• DA scores obtained from criterion referenced tests reflect the ages at which the behaviors assessed emerge in typically developing children based on information from the literature on child development or from older normed tests.

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Developmental Age Scores

• There are a number of problems with developmental age scores

– DA scores are not well related to the number of eligible children.

– DA scores are less precise estimates of children's abilities than scores based on standard deviations.

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Percent or Months Delay are Problematic in Eligibility Definitions

In general developmental age scores should not be subtracted or divided by children’s chronological ages.

Consequently it’s not a good idea to use months delay or percent delay to establish eligibility.

Contradictions in Eligibility Definitions

Definitions that use percent or months delay and standard deviations have built-in contradictions.

Developmental ages and standard deviations frequently don’t agree

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Comparison of Eligibility Based on Criteria of At least 30 Percent Delay OR Two Standard Deviations Below the Mean*

ChronologicAge

(Months)

Developmental

Age (Months)

PercentDelay

Standard Score

(70 = 2 SD)

Agreement on Eligibility Criteria

18 13 28% – not eligible

65 – eligible(under 2 SD)

Disagree

19 13 32% – eligible 65 – eligible Agree

20 14 30% – eligible 65 – eligible Agree

21 15 29% – not eligible

82 – not eligible

Agree

22 15 32% – eligible 82 – not eligible

Disagree

23 16-1816-18 22% – 30% 22% – 30% Yes and NoYes and No

87 – not eligible

AgreeAgree & & DisagreeDisagree

*Battelle Developmental Inventory Cognitive Domain Subtest Adapted from Andersson (2004). Appropriate and inappropriate interpretation and use of test scores in early intervention. Journal of Early Intervention, 27, 55–68.

Inaccuracies in Eligibility Definitions

When we use eligibility criteria that make use of inaccurate indicators of developmental level we are more likely to make mistakes about which children are eligible for Part C services.

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Avoid Using Criterion Referenced Tests for Determining Eligibility

• Criterion referenced tests do not provide an accurate way of knowing if a child’s development is delayed compared to typically developing peers.

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Establish a Rigorous Definition of Part C Eligibility

States should establish definitions of developmental delay that are --

clear, reliable and which make eligible only those children the state intends to serve.

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What is a “Rigorous” Definition?

A rigorous definition of developmental delay is reliable and valid:

• Reliable – different evaluators can use the definition independently and reach high levels of agreement on who is Part C eligible;

• Valid – high content validity – stakeholders agree that the definition is consistent with the level of delay that should make a child Part C eligible.

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Informed Clinical Opinion Is Not a Substitute for a Rigorous Definition• The use of informed clinical opinion

doesn’t eliminate the need for a definition of developmental delay.

• Informed clinical opinion is not a definition of eligibility.

• Informed clinical opinion is the outcome of a careful process for determining a child’s eligibility based on a review of information from multiple sources.

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Design a Rigorous Definition of Part C Eligibility

Tailor the definition to the group of children your state intends to serve.

– To design a rigorous definition of Part C eligibility first decide which children the state intends to serve and then create a definition that makes only those children eligible.

Design a Rigorous Definition of Part C Eligibility

• The criteria used to define children who are eligible for Part C should be clear, internally consistent and reflect state enrollment goals.

• The criteria used in a definition should make use of precise estimates of child development that can be compared to norms of typically developing peers

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A Rigorous Definition is Not Enough

How state Part C eligibility criteria are applied impacts enrollment:

• Eligibility criteria must be applied consistently in each community;

• Every community must have an effective child find process for recruiting Part C eligible children and their families.

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Recommendations

• Eligibility definitions should be rigorous

• Eligibility criteria using percent delay or months delay should be avoided;

• Informed clinical opinion should not be used as a substitute for a rigorous definition;

Recommendations

• States should track the level of agreement between the percentage of the population expected under their eligibility definition and the percentage enrolled.

• States should monitor whether the children they intend to serve are in fact the ones who are receiving Part C services.

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For additional information:

Steven A. Rosenberg, Ph.D.University of Colorado Denver4455 E. 12th Avenue, Campus Box C268-22Denver, CO 80220steven.rosenberg@ucdenver.edu

This work was supported by grants from the U.S. Department of Education, Office of Special Education Programs (OSEP) Grant No. H324T990026 (University of Colorado, Denver) and Grant No. H324T990006 (University of Connecticut Health Center), and Grant No. R40 MC 05473 from the Maternal and Child Health Bureau (Title V, Social Security Act), Health Resources and Services Administration, Department of Health and Human Services US Department of Health and Human Services, Administration on Developmental Disabilities, University Center of Excellence in Developmental Disabilities Education, Research and Service (UCEDD) Award # 90DD0632.

NECTAC Webinar Series on Early Identification and Part C EligibilitySession 2: A Rigorous Definition of Developmental DelayMarch 4, 2010

Thank you for listening.

Presentations from this series and their related resources are made available on the NECTAC Web Site at:

http://www.nectac.org/~calls/2010/earlypartc/earlypartc.asp