This dissertation is intended to provide guidance to psychologists and other early childhood professionals completing further testing of young children who have already been identified as being at risk of having autism spectrum disorder. Therefore general screening and surveillance measures were omitted from the dissertation. The main distinction between autism spectrum disorder instruments involves their intended purpose as a screening device or a
diagnostic measure. Screening tools are instruments that are designed to help clinicians identify infants and children who are at risk of having a developmental delay or concerns and/or those who would most benefit from a more comprehensive assessment (Baird et al., 2001).
Screening measures vary according to the level of screening. Level 1 screening includes routine developmental surveillance usually provided by pediatricians or others who provide general health services to young children. These measures screen for deficits across a broad range of developmental problems (i.e. motor, cognitive or language delay) in general populations of children. These measures often identify children with autism as well as those with a broad range of developmental disorders. Many Level 1 screening measures are used to evaluate large numbers of children, are brief and easy to administer and completed by parents (Coonrod & Stone, 2005; Filipek et al., 2000). Therefore many are available in Spanish in the form of parent report questionnaires. A complete list of screening tools frequently used as a first step in
identifying autism spectrum disorder, including those measures available in Spanish is available online from Health Partner’s.
Level 2 screening measures for autism spectrum disorder are specifically used to differentiate children at risk for autism spectrum disorder from those children at risk for other
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developmental disorders such as language impairment (Coonrod & Stone, 2005). Level 2 measures are sometimes used after a child fails the initial screening (Coonrod & Stone, 2005). Level 2 screening measures for autism spectrum disorder differ from diagnostic measures in that they typically require less time, training, and experience to administer. Therefore they are frequently included as part of a more comprehensive diagnostic assessment. The purpose of a comprehensive assessment is to obtain and interpret data necessary for diagnosis and effective intervention. Therefore, assessment measures are instruments that provide a thorough assessment of developmental, language/communication, social or neuropsychological functioning.
For further review of Level 1 and Level 2 screening measures available for use with children suspected of having autism spectrum disorder (Baird et al., 2001; Coonrod & Stone, 2005; Filipek et al., 2000; Matson & Sipes, 2010; J. Williams & Brayne, 2006). Several measures are available in Spanish including the Checklist for Autism in Toddlers (CHAT); the Modified Checklist for Autism in Toddlers (MCHAT); the Battelle Development Inventory Screening Tool- Second Edition (BDI-ST); and the Brigance Screen-Second Edition. Additional information related to screening tools can also be found on the First Signs Website, the American Academy of Pediatrics and the Centers for Disease Control.
Despite the fact that these instruments are often the first step in the diagnostic process and are sometimes used to confirm a diagnosis in order for a child to receive services, research on the use of the Spanish translations or their use with Latino families is scarce (M. Williams et al., 2009). These screening measures cannot be used as the primary diagnostic tool; however since these brief screens are often used to complement a more comprehensive evaluation a few notable measures specific to autism spectrum disorder were selected for review.
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Autism Detection in Early Childhood- Spanish Version (ADEC-SP). The manual of
the Autism Detection in Early Childhood-Spanish Version (ADEC-SP; Hedley, Young, & Gallegos, 2010; Deteccíon del Autismo en la Infancia) is still a research version that is only available by contacting the author. Although the ADEC-SP was initially introduced as a
screening instrument to assist with the early identification of young children with autism, it is a notable measure since it was effectively validated on a sample of children in Mexico (Hedley et al., 2010). The ADEC-SP also shows promise as a useful measure to assist with the diagnosis of autism spectrum disorder since it was meant to be administered with limited training. Unlike the ADOS, that requires a significant amount of time and training to administer, the ADEC-SP appears to be a more clinically useful alternative. In addition, the ADEC-SP relies primarily on observation and the administration is mostly non-verbal, therefore reducing cultural factors that can sometimes interfere with obtaining accurate information.
The original English version of the ADEC was developed in Australia (Vacca, 2007) and is available to purchase on line. The ADEC-SP is designed as an interactive, behaviorally based Level 2 screener to detect autism spectrum disorder in preverbal toddlers as young as 12 months. The 16 items of the ADEC-SP including an “Adaptation Period” can be completed quickly (approximately 10 to 15 minutes) and can be integrated as part of a more comprehensive assessment. The ADEC-SP includes behaviors that are consistent with the DSM-IV criteria for autism and are included in the “Sequence to be followed for the Evaluation” (response to name; imitation; ritualistic play; joint attention; eye contact; functional play; pretend play; reciprocity of smile; reaction to common sounds; gaze monitoring; following verbal commands; delayed language; anticipation of social advances; nestling; use of gestures; and impairment in task switching). Administration of the ADEC-SP is play based and child centered. The behaviors of
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focus are observed and easily rated with “0” denoting a typical response and a “1” or “2” indicating an atypical response. Following observation, the ratings are summed to provide an overall score with total scores ranging from 0 to 32 with a score of 11 and over indicating risk for autism.
The ADEC-SP was translated from the original English version into Spanish using international guidelines for cross cultural translation including consideration of cultural and linguistic differences (Hedley et al., 2010). The translated instrument was also field tested and reviewed by several bilingual psychologists to identify any misinterpretations in application following the translation. Participants in the research sample were recruited from several clinics in Mexico that treat children with autism and other disorders. Functional equivalence of the ADEC-SP was confirmed with the sample of Mexican children.
Overall, the ADEC-SP showed good correlation between sensitivity (.79 - .94) and specificity rates ranged from .88 to 1.00 across all of the samples. Inter-rater reliability was reported to be high between the ADEC-SP and the English version (.96) and internal consistency was .73. Score means and standard deviations of the translated version did not differ significantly from the original means in the Australian sample, suggesting good test score equivalence. In addition, the Spanish version was able to accurately identify a diagnosis of PDD in a group of toddlers 19 to 36 months who had previously been identified as having a delay and was also able to accurately predict autism in children who were referred due to a suspected diagnosis. ADEC- SP scores were also significantly correlated with the Childhood Autism Rating Scale (CARS; Schopler, Reichler, & Renner, 1988) and the Autism Diagnostic Interview-Revised (ADI-R; Le Couteur, Lord, & Rutter, 2003) . In fact, the ADEC-SP was found to have greater sensitivity for
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autism in toddlers less than 36 months when compared to the CARS and the ADI- R (Hedley et al., 2010).
A notable benefit to using the ADEC-SP is that it relies on observation and is mostly non- verbal which can reduce concerns related to the Spanish language translation. This may also lessen the impact of cultural factors since the examiner is not dependent on inaccurate parental reports or the use of assessment methods where the behavior is not directly observed by the assessor (Hedley et al., 2010; Overton et al., 2007; Reznick, Baranek, Reavis, Watson, & Crais, 2007). The ADEC-SP can be used to supplement a parent interview, since obvious signs of abnormality in the way a child plays with toys to a parent might be seen very differently in direct observation to the experienced clinician. A noteworthy strength of the ADEC-SP is its’
diagnostic sensitivity with young children. The authors caution against using the ADEC-SP with children over 36 months. This is dissimilar to other measures that have been noted to lack sensitivity, such as the Autism Diagnostic Observation Schedule (ADOS; Lord, Rutter, DiLavore, & Risi, 1999), when used with young children, subsequently requiring alternative modules and algorithms. The ADEC-SP promises to be a useful instrument to increase the early identification of autism in Latino infants. Future studies of the Spanish version of the ADEC must be conducted to support its’ validity with Spanish speaking infants in the U.S.
The Childhood Autism Rating Scale (CARS). The Childhood Autism Rating Scale
(CARS) was developed by Schopler, Reichler, and Renner (1988) and is one of the earliest rating scales to assess autism. Although not available in Spanish, the CARS is one of the most
frequently used measures of behaviors associated with autism (Allen, Robins, & Decker, 2008; Lord & Corsello, 2005; Luiselli et al., 2001), therefore it was included for review. Initially developed as a Level 2 screen to rate behaviors, its’ use is widespread as a diagnostic tool
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(Luyster et al., 2005), and has also been adapted to assess the parent’s perception of their child’s level of functioning (Tobing & Glenwick, 2002). The most recent version of the CARS, was published in 2010 and as of this writing, limited research is available that includes the second edition. Therefore the following includes a review of the first edition of the CARS.
The CARS was developed to discriminate children with autism from those with other developmental disorders. The CARS is appropriate for use with children over 24 months of age. It consists of 15 items that examine behaviors frequently associated with autism relevant to typically developing childhood norms including: relating to people; the ability to engage in imitative behavior; range and appropriateness of emotional response; body use and any presence of motor stereotypy; object use; adaptation to change; visual, auditory and tactile responses; fear or nervousness; verbal and nonverbal communication; activity level; cognitive skills; and general impressions of the degree of autism observed. The CARS uses a Likert scale ranging from 1 to 4 (1 = appropriate; 4 = severely abnormal). A total score is calculated and summed into a
composite score ranging from 0 to 60, with scores above 30 considered to be consistent with a diagnosis of autism; scores between 30 and 36.5 suggest mild to moderate autism; and scores between 37 and 60 suggest severe autism.
Several sources of information can be used to complete the CARS including direct observation of the child by the clinician, parent interview, parent rating of the child’s behaviors or a chart review. Although use of the CARS requires prior knowledge and experience in the diagnosis of autism, the publishers note that professionals with only minimal exposure to autism can be easily trained in its’ use. One of the benefits of the CARS is that it is quick and
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Although the CARS is frequently used, it is also criticized since it is based on
conceptualizations of autism prior to the DSM-IV (American Psychiatric Association, 1994) and does not measure some constructs now considered important to the autism diagnosis (e.g., joint attention) subsequently decreasing its’ validity (Rellini, Tortolani, Trillo, Carbone, & Montecchi, 2004; Saemundsen, Magnusson, Smari, & Sigurdardottir, 2003). Several studies of the CARS have reported good reliability and validity (Lord & Corsello, 2005; Perry, Condillac, Freeman, Dunn-Geier, & Belair, 2005; Rellini et al., 2004; Volkmar & Marans, 1999). However,
sensitivity and specificity levels vary, with some studies reporting sensitivity estimates ranging from 47% to 98% and specificity ranging from 92% to 94% (R. C. Eaves & Milner, 1993; Wiggins & Robins, 2008). The CARS has also been compared to several instruments including the ADI-R and ADOS-G (Rellini et al., 2004; Saemundsen et al., 2003; Ventola et al., 2006). It is important to recognize that these results are based on outdated diagnostic criteria, yet the CARS continues to be used to confirm the validity of other measures of autism (Matson, Hess, Mahan, & Fodstad, 2010) as well as to diagnose autism spectrum disorder in young children (Delinicolas & Young, 2007; Stone, McMahon, Yoder, & Walden, 2007). Several studies have found that the CARS tends to over identify children with intellectual disability but who do not have autism, as having autistic disorder (DiLavore, Lord, & Rutter, 1995; Lord, 1995; Pilowsky, Yirmiya, Shulman, & Dover, 1998; Saemundsen et al., 2003; Volkmar & Marans, 1999).
The CARS has been found to be a valid and reliable measure when translated and used in Brazil (A. Pereira, Riesgo, & Wagner, 2008), Korean (Shin & Kim, 1998) and Japan (Tachimori, Osada, & Kurita, 2003). It is important to note that although the CARS is frequently used to identify autism in Latino children (M. Williams et al., 2009), including studies of prevalence (Yeargin-Allsopp et al., 2003), few studies have been conducted that include a significant sample
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of Latino children. In addition, neither the original CARS nor the second edition have been translated into Spanish or validated on a Spanish speaking population in the United States. Published studies using a Spanish version of the CARS have primarily been conducted on adults with autism (García-Villamisar & Muela, 1998; García-Villamisar & Muela Morente, 2000). Although the CARS can be completed based on the clinician’s observations or a parent who is interviewed in Spanish, it has not been normed on a Spanish speaking population and is frequently translated informally by Spanish speaking users (M. Williams et al., 2009). Many professionals continue to use the CARS due to its’ ease of use and brief evaluation time; however the CARS is not well validated for the Latino population; is translated into Spanish without regard for the loss of psychometric properties; and has little research to support its’ use with Spanish speaking children and their families (M. Williams et al., 2009). In fact, use of the CARS may contribute to the under diagnosis of autism in Latino and Spanish speaking children. Future studies utilizing the CARS- II will hopefully fill this gap in the research.
Gilliam Autism Rating Scale (GARS). The Gilliam Autism Rating Scale (GARS) is a
checklist they can be used to identify and diagnose autism in individuals ages 3 and older (J. E. Gilliam, 1995). Like the CARS, the GARS is not available in Spanish but is frequently used to diagnosis autism spectrum disorder in children (Allen et al., 2008; M. Williams et al., 2009), therefore a review and critique is included. Although the second edition of the GARS (GARS- II) was released in 2006; the majority of research utilizes the original version. Therefore, the
following review will be limited to the first edition of the GARS.
The GARS examines autistic symptoms and their severity based on the DSM-IV (American Psychiatric Association, 1994) and the Autism Society of America (Autism Society of America, 1994). The rating scale can be completed in five to 10 minutes by a parent, teacher
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or mental health professional. Little training is required to complete and score the GARS. The 56 items on the instrument are divided into item 3 core subtests evaluating early stereotyped
behaviors, communication skills and social interaction. The Developmental Disturbances subtest is optional and gathers information from the caregiver about developmental history the first 3 years of life. Ratings are made using a four-point Likert Scale (ranging from 0 to 3), summed and converted to standard scores based on percentiles on the reference sample. The GARS ratings also yield a total score called the Autism Quotient (AQ). The AQ can be calculated from two, three or four subscales from the GARS. The total score of the AQ measures the “likelihood” that the child has autism and the severity of the disorder (AQ of 90 and above = likely autism; below 70 = unlikely autism). The Communication subtest is not completed for non-verbal
children and the Developmental Disturbance subtest is not completed when the respondent is not aware of the child’s developmental history.
The test was normed on 1,092 representative subjects with autism from 45 states in North America and in Canada; however, the diagnosis was not verified by a professional (J. E. Gilliam, 1995). The normative group included ratings by 720 teachers and 372 parents of children
between 3 and 22 years old with autism. The GARS manual reported internal consistency, test- retest reliability and inter-rater reliability all in the .80s and .90s (J. E. Gilliam, 1995). It is important to note that test-retest reliability was computed using the standard scores of a small sample of only 11 children, restricting the range of scores and impacting the results (Lecavalier, 2005). Neither item agreement nor classification agreement across time or rater were reported (J. E. Gilliam, 1995). Convergent validity was conducted using the ABC in a sample of 69 children from the normative group. Subscale correlations between the instruments ranged from .37 to .92 and the correlation of the total scores was .94 (J. E. Gilliam, 1995). Very little information is
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reported in the manual regarding the methodological procedures, the raters or the children with and without a diagnosis of autism. In addition, the children were not matched on demographic variables when the discriminant validity was determined.
Critics of the GARS have noted its’ poor sensitivity which may lead to false negatives and can ultimately interfere with early identification, delay referrals and early intervention (Lord & Corsello, 2005). Lecavalier (2005) found that almost half of all the items on the GARS were associated with the factor measuring repetitive and stereotyped behaviors as well as stereotyped and repetitive use of language and motor mannerisms. In addition, several social and
communicative deficits, commonly seen in children with autism spectrum disorder, such as play and imitative behaviors were not included or covered in the GARS. Lecavalier (2005) also reported the average AQ was significantly lower than reported in the test manual, suggesting low sensitivity. The Developmental Disturbance subscale was not significantly associated with the AQ or any of the subscales. The authors recommend caution when using the GARS as a diagnostic tool, and suggest a lower AQ cut-off score when screening for autism spectrum disorder.
South et al. (2002) found the GARS to have overall poor convergence with other
measures as well as low sensitivity. The authors examined data from the GARS on 119 children (average age 6.2 years old). The children had a diagnosis of autism confirmed by the ADOS and the ADI-R. The average AQ was 10 points below the suggested cut-off. The sensitivity of the GARS was low (.48) failing to correctly classify over half of the sample. In addition, the Developmental Disturbance subscale was not associated with the other subscales and was also weakly correlated with the total score (South et al., 2002). Convergent validity was also investigated comparing the GARS to the ADI-R and the ADOS. There were no significant
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correlations between the GARS and the ADOS. Correlations between the GARS and the ADI-R subscales were low (ranging from .21 to .26).
Due to the high rate of false positives, the GARS cannot be used in isolation for diagnostic purposes. Some research projects have used the GARS in conjunction with other instruments (Asano et al., 2001; Owley et al., 2001); however this can still result in misdiagnosis and under classification of children with autism spectrum disorder. Although the GARS is frequently used and has been recommended by many organizations and in many texts (Filipek et