How Do I Choose the Most Accurate Autism Test For My Client? 

Identifying autism shouldn’t depend on a single assessment, no matter how thorough or precise that assessment is. A clear diagnosis—one your client can trust, and you can feel confident delivering—is the result of a comprehensive evaluation, generally involving a team of health professionals. The Centers for Disease Control and Prevention (CDC) recommends that clinicians gather information from several sources, including the parents’ account of their child’s development, diagnostic assessments, and professional observations (CDC, 2022).  

The diagnostic tools you select are a critical part of a comprehensive evaluation. Here’s a quick primer on the types of assessments many clinicians use in an autism evaluation.  

Developmental screening tools. 

Screening tools aren’t used in a diagnostic evaluation. Instead, parents and health care providers use these quick questionnaires and checklists to identify children whose development may be atypical and who may have a higher likelihood of autism.  

Rating scales

Rating scales are typically used to determine how severe the symptoms or characteristics of a condition are. They often ask parents, the client, or observers to rate different behaviors or characteristics on a scale of progressive intensity.

Interviews 

Diagnostic interviews can be either structured, where the interviewer asks standardized questions in a pre-determined sequence, or semi-structured, where the interviewer has some flexibility to individualize follow-up questions (Mueller & Segal, 2015).

Observations 

Observations typically involve structured interactions between an evaluator and the person being evaluated. Interactions may involve objects, movements, or tasks—and the goal of each activity is to provide the child with opportunities to communicate with the observer (Park et al., 2018).   

Most of the time, an autism evaluation includes more than one type of assessment so clinicians can create a complete picture of a child’s development. Given the range of available tools, how do you go about choosing which ones to use? Here are a few questions to consider as you weigh your options

Does the Test Identify Autism Accurately?  

You’ll need a diagnostic tool that is sensitive, which means it correctly identifies the diagnostic criteria for autism specified by the Diagnostic and Statistical Manual for Mental Health Disorders, Fifth Edition, Text Revision (DSM-5-TR). The test should be specific, which means it identifies when behavior is typical. An autism assessment should also be reliable, which means that when people administer it over and over, the results are the same. In other words, you need a test that researchers and health professionals trust because it correctly identifies the characteristics of autism.  

The Autism Diagnostic Observation Schedule, Second Edition (ADOS®-2) is considered by many to be the “gold standard” for autism assessments (Brian et al., 2019). There are also several other commonly used measures:

• Autism Diagnostic Interview–Revised (ADI®-R) 
• Childhood Autism Rating Scale, Second Edition (CARS™2) 
• Monteiro Interview Guidelines for Diagnosing the Autism Spectrum, Second Edition (MIGDAS™-2) 
• Gilliam Autism Rating Scale, Third Edition (GARS-3) 

What Are the Characteristics of Your Client?   

The “Guidelines for Assessments and Evaluations” of the American Psychological Association (APA) suggest that an evaluator consider the age, sex, ethnicity, and primary language of the client when deciding which assessment to use. The guidelines also recommend that evaluators know the demographics of the people included in the normative sample for the assessment.  

The normative data you gather from an assessment may not be accurate if your client’s characteristics aren’t represented among the test’s norm group, the APA says (2020). If the test relies on tasks that have no cultural familiarity to your client, the results could be similarly skewed. When a mismatched test provides misleading results, clients may not get the services they need—and unfair health disparities can result (Thunt, 2021).   

Learn more: Why Are So Many Autistic Girls & Women Missing Out on Early Identification?    

Is the Test Available in the Language You Need?   

When people take assessments in languages they are still learning, the results may be affected by the linguistic demands of the test, rather than by autism. Autism may be under-identified among students who are English-language learners, possibly because autism and English-language learners sometimes have delays, challenges, or differences in 

• social communication, 
• pragmatic speech, 
• language acquisition, 
• nonverbal communication, and/or 
• social behaviors. 

If an autism assessment tool isn’t available in the language you need, researchers recommend using assessment tools that aren’t dependent on language. It’s also a good idea to interview multiple informants and to provide flexible time requirements during testing (Dennison et al., 2018).

What Other Assessments Will You Need to Complete the Evaluation?   

One of the goals of an evaluation is determining whether symptoms could be better explained by another health condition. For that reason, your diagnostic team will likely need to determine whether any other conditions are causing symptoms that look like autism characteristics. Health conditions such as these can complicate an autism evaluation: 

• attention-deficit/hyperactivity disorder 
• specific learning disabilities 
• anxiety 
• depression 
• bipolar disorder 
• intellectual development disorder 
• social communication disorder 
• obsessive compulsive disorder 
• Tourette’s syndrome 

In addition to looking for comorbidities and overlapping symptoms, many clinicians also assess adaptive behavior skills. Studies show that parents aren’t just concerned about a formal diagnosis, but about the child’s daily functional needs—whatever the diagnosis turns out to be.

Learn more: Study Highlights the Need to Assess Mental Health in Autistic Youth

Where Will the Assessment Be Administered?    

It’s important to consider where and how you’ll administer an assessment. The amount of time you’ll need to complete the evaluation and the cost of an assessment are two other practical aspects to consider.  

The social distancing requirements of the COVID-19 pandemic spurred a dramatic surge in the use of telehealth assessments. In some instances, such as rural locations where health care and psychological services may be limited, telehealth services can improve access to care (Zwaigenbaum et al., 2021). Even so, not every assessment has been validated for use online (Spain et al., 2022). The ADOS-2 is validated for in-person use. But other auxiliary diagnostic tools are available for use as telehealth assessments: 

• Adaptive Behavior Assessment System, Third Edition (ABAS®-3)
• Social Responsiveness Scale, Second Edition (SRS™-2)
• Sensory Processing Measure, Second Edition (SPM™-2)
• Developmental Profile 3 (DP™-3) and Developmental Profile 4 (DP™-4)
• Social Communication Questionnaire (SCQ™)
• Developmental Behavior Checklist 2 (DBC™2)
• Revised Children’s Manifest Anxiety Scale, Second Edition (RCMAS™-2)
• Piers-Harris Self-Concept Scale, Third Edition (Piers-Harris™ 3)

What Training Will You Need to Feel Confident Administering, Scoring, and Interpreting the Test?     

Becoming skilled at giving and interpreting assessments doesn’t happen overnight. It takes experience and ongoing training, especially as assessments are revised and updated in response to new research. As you make decisions about which tests to select, consider the resources available to help train you in the use of each tool. 

Can you participate in webinars, workshops, or continuing education to better understand test items and how to interpret responses? Do you have access to seasoned assessment professionals to guide you, not only in choosing the best test for the situation but in using the tool to identify autism? Are there mentors at your clinic or in your school who can walk you through the process? 

It’s important to say that trained, experienced professionals can identify autism without using a formal assessment—but in many settings, unlocking services and supports requires the use of a validated diagnostic tool. The better you understand your client’s characteristics and needs, the better you’ll be at choosing the best test for each person in your care.

Further Reading on Autism

• The WPS In-Depth Guide Autism and ADHD 
• Understanding the Complicated Interplay of Autism and ADHD
• How Autism and ADHD Can Disrupt Interoception
• How to Choose the Best Autism Assessment for Your Client
• Best Practices in Autism Assessment
• Autism Conversations: Individualizing Educational Interventions with the MIGDAS™-2 Evaluation Process

Videos and Webinars on Autism

• How Cyberbullying Impacts Students On and Off the Autism Spectrum
• Conversation Over Labels: A Better Way to Understand Autism
• Autism Spectrum Brains 'Get Energy' from These Things