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Psychometric Development of a New Inventory to Assess Symptoms Across the Spectrum of Autism. Presented By Peter D. Marle, B.A. Presented by Peter D. Marle, B.A. Coolidge Autistic Symptoms Survey. O verview of Autism. History and Popular Conceptions of Autism

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Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Psychometric Development of a New Inventory to Assess Symptoms Across the Spectrum of Autism

Presented By

Peter D. Marle, B.A.

Presented by

Peter D. Marle, B.A.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • History and Popular Conceptions of Autism

    • Possible accounts written as early as the 16th century (Martin Luther)

    • First psychiatric evaluations – early 20th century (De Sanctis, Earl, & Potter)

    • First scientific research – 1943 (Leo Kanner) and 1944 (Hans Asperger)

      • Comparing Kanner’s and Asperger’s narratives

        • Both differentiated autistic behaviors in the children from schizophrenia

        • Children studied had milder forms of autism

        • Asperger emphasized the malicious behaviors of the children

        • Kanner suspected the origin of autism to come from cold parents

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Controversies

    • Bettelheim and “refrigerator mothers”

    • Rimland

    • Jenny McCarthy

      • Vaccinations causal to autism?

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • History of the Diagnosis of Autism

    • Diagnostic and Statistical Manual of Mental Disorders (DSM; 1952)

      • No diagnosable autistic condition

      • Most synonymous diagnosis: Schizophrenic reaction, childhood type

    • DSM-II (1968)

      • Largely unchanged regarding the diagnosis of autism

    • DSM-III (1980)

      • Infantile autism

    • DSM-III-R(1987)

      • Autistic disorder

      • Pervasive developmental disorder – not otherwise specified

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • History of the Diagnosis of Autism

    • DSM-IV (1994)

      • Autistic Disorder

      • Childhood disintegrative disorder

      • Asperger’s Disorder

      • Pervasive developmental disorder – not otherwise specified

    • DSM-IV-TR (2000)

      • Largely unchanged regarding the diagnosis of autism

    • DSM-5 (2013)

      • Autism Spectrum Disorder

        • Continuum, with three degrees of severity

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Proposed DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

    • Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays

    • Restricted, repetitive patterns of behavior, interests, or activities

    • Symptoms must be present in early childhood

    • Symptoms together limit and impair everyday functioning

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Proposed DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

    • Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays, manifested by

    • all three of the following:

      • Social Interactions:

      • abnormal social approach, conversation, reduced sharing of interests and emotions

      • Nonverbal Communication (includes verbal):

      • abnormal eye contact, body language, facial expressions, and gestures

      • Peer Relationships:

      • adjustment of behavior to suit social contexts, imaginative play, seems not interested

      • in people

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Proposed DSM-5 Diagnostic Criteria for Autism Spectrum Disorder

    • Restricted, repetitive patterns of behavior, interests, or activities as manifested by at least two of  the following:

      • Stereotypies:

      • repetitive speech, motor movements, use of objects

      • Routine:

      • need for routine, patterns of behavior, resists change

      • Fixations:

      • fixated interests

      • Sensory Integration:

      • hyper and/or hypo-reactive to environmental stimuli

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Current Methods for Diagnosing Autism

    • Prevalence rate between 1:88 and 1:2000 (males 4 x more likely)

    • Combination of clinical observation, use of diagnostic tools, and parental reports

    • Current diagnostic tools

      • Autism Diagnostic Interview-Revised

      • Autism Diagnostic Observation Schedule

      • Childhood Autism Rating Scale

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Overview of Autism

  • Need for an Updated Diagnostic Tool

    • Current tools may soon be outdated

  • Development of the Coolidge Autistic Spectrum Survey

    • Created to examine similarities between Asperger’s disorder and high functioning autism (2007)

    • Another study later investigated the differentiation of milder forms of ASD and schizoid personality disorder traits (in press)

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Present Study

  • Purpose

    • To redesign the CASS in order to provide coverage for the new criteria in DSM-5 and to extend the lower age range of the CASS to approximately 2 to 3 years

  • Hypotheses

    • A 1-component solution (as determined by principal components analysis) would best fit the structures of the new 83-item CASS and 39-item CASS-T (based on a previous study); although, DSM-5 diagnostic criteria for ASD may suggest multiple components.

    • The new CASS and CASS-T would show good internal reliability (Cronbach’s α ≥ .80).

    • The surveys would have an adequate split-half reliability (r ≥ .80).

    • The surveys would significantly differentiate among children with

      • milder forms of autism (e.g., Asperger’s disorder and high-functioning autism)

      • moderate-to-severe forms of autistic spectrum disorders

      • no diagnoses (i.e., a group-matched control group)

    • There would be a strong, positive correlation between the CASS-T and the CASS means.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Present Study

  • Participants

  • Materials

    • Informed Consent Form

    • Demographic Sheet

    • 39-item CASS-T (Retrospective)

    • 83-item CASS

  • Procedure

    • All data were collected with approval from the University’s institutional review board

    • Packets were either

      • hand-delivered to parents via a CITI-trained researcher (i.e., Peter D. Marle) or

      • given in an electronic format (via a secure online survey host; i.e., PsychData.com)

    • Packets took approximately 30 min to complete

    • Participants were given the option of returning the materials via a SASE or returning the materials to the CITI-trained researcher

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 1

  • A 1-component solution would provide the best fit for the CASS and the CASS-T

  • (accounting for at least 50% of the variance)

    • 83-item CASS

      • A 1-component solution accounted for about 52% of the variance

    • 39-item CASS-T

      • Either a 4-component (total variance explained = 65.5%) or

      • 5-component solution (total variance explained = 69.5%) best fit the data

* Supplemental Information on Component Solutions

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 2

  • The new CASS and CASS-T would show good internal reliability (Cronbach’s α ≥ .80)

    • 83-item CASS

      • Cronbach’s α = .99 (n = 86)

    • 39-item CASS-T

      • Cronbach’s α = .97 (n = 88)

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 3

  • The CASS and CASS-T would have adequate split-half reliabilities (r ≥ .80)

    • 83-item CASS

      • r(87) = .98, p < .001

    • 39-item CASS-T

      • r(90) = .95, p < .001

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 4

  • There would be significant differences among the group means for the CASS and CASS-T

  • the moderate-to-severe autism group would have the significantly highest mean,

  • the mild autism group would have the second highest mean, and

  • the group-matched control group would have the significantly lowest mean

    • 83-item CASS

      • F(2, 64) = 199.93,

      • p< .0005; η2 = .86

    • 39-item CASS-T

      • F(2, 64) = 165.56,

      • p< .0005; η2 = .84

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 4

  • There would be significant differences among the group means for the CASS and CASS-T

  • the moderate-to-severe autism group would have the significantly highest mean,

  • the mild autism group would have the second highest mean, and

  • the group-matched control group would have the significantly lowest mean

    • 83-item CASS

      • F(2, 64) = 199.93,

      • p< .0005; η2 = .86

    • 39-item CASS-T

      • F(2, 64) = 165.56,

      • p< .0005; η2 = .84

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Results

  • Hypothesis 5

  • There would be a strong, positive correlation between the CASS-T and the CASS means

    • Correlation coefficient

      • r(92) = .89, p < .0005

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 1

  • A 1-component solution would provide the best fit for the CASS and the CASS-T

  • (accounting for at least 50% of the variance)

    • 83-item CASS

      • A 1-component solution accounted for about 52% of the variance

      • Hypothesis supported

    • 39-item CASS-T

      • Either a 4-component (total variance explained = 65.5%) or

      • 5-component solution (total variance explained = 69.5%) best fit the data

      • Hypothesis not supported

        • DSM-5diagnostic criteria for ASD, sans sensory issues

        • Physical contact

        • Developmental milestones

        • Sensory issues

        • The 5-component solution added a stereotypies and humor component

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 1

    • 39-item CASS-T

      • DSM-5 diagnostic criteria for ASD, sans sensory issues

      • Physical contact

      • Developmental milestones

      • Sensory issues

      • The 5-component solution added a stereotypies and humor component

    • DSM-5 Criteria

      • Social Interactions

      • Nonverbal Communication

      • Peer Relationships

      • Stereotypies

      • Routine

      • Fixations

      • Sensory Integration

}manifested by all three

}manifested by at least two

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 2

  • The new CASS and CASS-T would show good internal reliability (Cronbach’s α ≥ .80)

    • 83-item CASS

      • Cronbach’s α = .99 (n = 86)

      • Hypothesis supported

    • 39-item CASS-T

      • Cronbach’s α = .97 (n = 88)

      • Hypothesis supported

    • Alphas too high?

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 3

  • The CASS and CASS-T would have adequate split-half reliabilities (r ≥ .80)

    • 83-item CASS

      • r(87) = .98

      • Hypothesis supported

    • 39-item CASS-T

      • r(90) = .95

      • Hypothesis supported

    • Comparing split-half reliability and Cronbach’s α

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 4

  • There would be significant differences among the group means for the CASS and CASS-T

  • the moderate-to-severe autism group would have the significantly highest mean,

  • the mild autism group would have the second highest mean, and

  • the group-matched control group would have the significantly lowest mean

    • 83-item CASS

      • F(2, 64) = 199.93,

      • p< .0005; η2 = .86

      • Hypothesis supported

    • 39-item CASS-T

      • F(2, 64) = 165.56,

      • p< .0005; η2 = .84

      • Hypothesis supported

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 5

  • There would be a strong, positive correlation between the CASS-T and the CASS means

    • Correlation coefficient

      • r(92) = .89, p < .0005

      • Hypothesis supported

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 5

  • There would be a strong, positive correlation between the CASS-T and the CASS means

    • Correlation coefficient

      • r(92) = .89, p < .0005

      • Hypothesis supported

Only midpoints given.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Discussion

  • Hypothesis 5

  • There would be a strong, positive correlation between the CASS-T and the CASS means

    • Correlation coefficient

      • r(92) = .89, p < .0005

      • Hypothesis supported

Midpoints with 1 standard deviation projection given.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Limitations and Future Research

  • This study did not investigate the differentiation of moderate ASD

  • Future research into the CASS and the CASS-T should explore this.

  • This study used parent-as-respondent data

  • Cost vs. accuracy/error

  • Small sample size for the PCA

  • This study served as a preliminary component structure assessment of the surveys.

  • Future PCA with a larger pool of participants is recommended.

  • Test-retest reliability was not assessed

  • This study assessed split-half reliability.

  • Future studies should investigate time-based reliability.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Limitations and Future Research

  • Sensitivity and specificity of surveys not assessed

  • Future research investigating the accuracy of the surveys to accurately categorize ASD into groups, as well as to accurately assess any non-ASD diagnosis.

  • Gender and age differences regarding the surveys should be analyzed

  • Future research should explore differences in item responses by age and gender.

  • Sensory integration disorder and the CASS

  • Because of the possible current trend of misdiagnosing children with an ASD who may only have sensory integration problems, future research with the CASS should assess the differentiation of these children.

Coolidge Autistic Symptoms Survey


Psychometric development of a new inventory to assess symptoms across the spectrum of autism

Thank you!

Questions?

Coolidge Autistic Symptoms Survey