There has been a dramatic worldwide increase in reported cases of autism over the past decade. The prevalence rates have risen steadily, from one in 150, to one in 110, and now to one in every 88 children. This represents a 78 percent increase in the number of children identified with an autism spectrum disorder (ASD) over the past decade. Yet, compared to population estimates, identification rates have not kept pace in our schools. It is not unusual for children with less severe symptoms of ASD to go unidentified until well after entering school. As a result, it is critical that school-based educational support personnel (e.g., special educators, school counselors, speech/language pathologists, social workers, and school psychologists) give greater priority to case finding, screening, and assessment to ensure that children with ASD are identified and have access to the appropriate intervention services.
The primary goals of conducting an autism spectrum assessment are to determine the presence and severity of an ASD, develop interventions for intervention/treatment planning, and collect data that will help with progress monitoring. Professionals must also determine whether an ASD has been overlooked or misclassified, describe coexisting (comorbid) disorders, or identify an alternative classification. Interviews and observation schedules, together with an interdisciplinary assessment of social behavior, language and communication, adaptive behavior, motor skills, sensory issues, atypical behaviors, and cognitive functioning are recommended best practice procedures.
There are several important considerations that should inform the assessment process. First, a developmental perspective is critically important. While the core symptoms of are present during early childhood, ASD is a lifelong disability that affects the individual’s adaptive functioning from childhood through adulthood. Utilizing a developmental assessment framework provides a yardstick for understanding the severity and quality of delays or atypicality. Because ASD affects multiple developmental domains, the use of an interdisciplinary team constitutes best practice for assessment and diagnosis of ASD. A team approach is essential for establishing a developmental and psychosocial profile of the child in order to guide intervention planning. The following principles should guide the assessment process.
Children who screen positive for ASD should be referred for a comprehensive assessment. Although screening tools have utility in broadly identifying children who are at-risk for an autism spectrum condition, they are not recommended as stand alone diagnostic instruments or as a substitute for a more inclusive assessment.
Assessment should involve careful attention to the signs and symptoms consistent with ASD as well as other coexisting childhood disorders.
When a student is suspected of having an ASD, a review of his or her developmental history in areas such as speech, communication, social and play skills is an important first step in the assessment process.
A family medical history and review of psychosocial factors that may play a role in the child’s development is a significant component of the assessment process.
The integration of information from multiple sources will strengthen the reliability of the assessment results.
Evaluation of academic achievement should be included in assessment and intervention planning to address learning and behavioral concerns in the child’s overall school functioning.
Assessment procedures should be designed to assist in the development of instructional objectives and intervention strategies based on the student’s unique pattern of strengths and weaknesses.
Because impairment in communication and social reciprocity are core features of ASD, a comprehensive developmental assessment should include both domains.
A comprehensive developmental assessment approach requires the use of multiple measures including, but not limited to, verbal reports, direct observation, direct interaction and evaluation, and third-party reports. Assessment is a continuous process, rather than a series of separate actions, and procedures may overlap and take place in tandem. While specific activities of the assessment process will vary and depend on the child’s age, history, referral questions, and any previous evaluations and assessments, the following components should be included in a best practice assessment and evaluation of ASD in school-age children.
Developmental and medical history
Medical screening and/or evaluation
Parent/teacher ratings of social competence
Direct child observation
Adaptive behavior assessment
Communication and language assessment
Children with ASD often demonstrate additional problems beyond those associated with the core domains. Therefore, other areas should be included in the assessment battery depending on the referral question, history, and core evaluation results. These may include: