Autism spectrum disorders (ASDs), also called pervasive developmental disorders in the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revised), constitute a group of neurodevelopmental disorders that coalesce around a common theme of impairments in social functioning, communication abilities, and repetitive or rigid behaviors. The ASDs considered here include autism/autistic disorder, Asperger disorder/Asperger syndrome (AS), and pervasive developmental disorder not otherwise specified. This article focuses on autism/autistic disorder screening and its early identification, with a brief mention for AS screening, as there are limited tools and no recommendation for universal screening for AS.
Given the increasing media coverage of autism over the last decade and increasing awareness among professionals and lay persons, in part due to the Centers for Disease Control and Prevention (CDC) Learn the Signs, Act Early campaign (a collaboration of the CDC National Center on Birth Defects and Developmental Disabilities, American Academy of Pediatrics [AAP], Autism Speaks, First Signs, Autism Society of America, and Organization for Autism Research), autism has emerged into the mainstream consciousness and is no longer considered a rare disorder as it once was (5.2:10,000). However, with the prevalence now estimated at 1 in 110, it is more than likely that every pediatrician, family practitioner, and nurse practitioner who provides care for children will encounter at least one child diagnosed with (or suspected of having) autism in the course of well-child and sick care. Often, the pediatrician is the first professional the parents or caregivers approach with concerns about their child’s development and suspicion of autism. Pediatricians are in an advantageous position of having multiple encounters for developmental surveillance.
There is no lack of information when it comes to professional education about autism screening, diagnosis, and interventions. The AAP has published comprehensive practice guidelines and an autism tool kit. Among grassroots organizations, Autism Speaks and First Signs provide information on autism mainly for lay persons, but are valuable sources of information for professionals as well. The Learn the Signs, Act Early campaign aims to increase provider awareness of the importance of early intervention in diagnosing and managing developmental disorders including autism ( Table 1 ).
| Resource | Materials for Physicians |
|---|---|
| Autism Speaks http://www.autismspeaks.org | Nation’s largest autism science and advocacy organization, dedicated to funding research; increasing awareness of ASDs; and advocating for the needs of individuals with autism and their families The Video Glossary (formerly under First Signs) demonstrates the phenotype and variations of social, communicative, and behavior symptoms in ASDs and how these vary from typical development. This is a helpful refresher not just for physicians, but also serves as a teaching tool for trainees and even parents and caregivers. It also contains video clips demonstrating different types of therapies available for children with ASDs |
| Centers for Disease Control & Prevention National Center on Birth Defects & Developmental Disabilities http://www.cdc.gov/ncbddd/autism/ | “Learn the Signs, Act Early” campaign aims to educate parents and professionals about childhood development, including early warning signs of autism and other developmental disorders, and encourages developmental screening and intervention. The Web site has lots of free downloadable and print materials for physicians to use in the office, including informational cards, fact sheets, and brochures |
| First Signs http://www.firstsigns.org/ | Public awareness and training program designed to educate pediatric practitioners, clinicians, early childhood educators, and parents about the importance of early detection and intervention of autism and other developmental disorders. Its Web site offers downloadable, free, and purchasable materials for clinicians to use in the office and in parent education |
Despite all this information, pediatrician surveys in 2004 revealed that only 8% actually screen for autism spectrum disorders (ASDs). Although this increased to 42% in a survey in 2008, this is not close to the expectation that all children must be screened for ASDs. One possible reason for the low screening rates may be unfamiliarity with the ASD screening tools. There are currently practicing pediatricians who trained when autism was a rare condition, when no screening tools were universally available. Nowadays, pediatric residency programs have mandatory developmental-behavioral pediatric rotations, and there is a plethora of information regarding screening tools and identification. Ongoing training and awareness is a key for professionals to access and use the tools available for screening for autism. The CDC Act Early project in collaboration with the Association of University Centers on Disabilities convened regional “Act Early” summits to bring together key state stakeholders to address the increasing demand for evidence-based practices for children with ASDs to and create action plans including increasing awareness among professionals. Other initiatives include the Autism ALARM (Autism is prevalent; Listen to parents; Act early; Refer; Monitor) funded by a cooperative agreement between the AAP and the National Center on Birth Defects and Developmental Disabilities at the CDC and Medical Home Initiatives.
What is a pediatrician to do?
The AAP recommends developmental surveillance at every well-child visit and developmental screening using standardized tools at 9-, 18-, and 24- or 30-month visits, or whenever parent or provider concern is expressed. In addition, autism-specific screenings are recommended at the 18- and 24-month visits (the AAP screening algorithm can be accessed at ). Surveillance and screening activities should be performed within the medical home and coordinated with tracking and intervention services available in the community.
Screening tools are generally classified as Level 1 (administered to all children and meant to identify children at risk for an ASD in contrast to those with typical development) and Level 2 (administered to a referred population in early intervention and diagnostic clinics, and meant to differentiate between children at risk for an ASD and other developmental disorders) ( Table 2 ). For a primary care pediatrician, Level 1 screening tools are most appropriate in terms of the accessible population and in the context of a medical home. Although the choice of screening tool itself will vary from clinician to clinician, based on cost, availability, and familiarity, the tenets of using a screening tool must always be adhered to:
- 1.
Autism screening is not meant to provide a diagnosis, merely to offer guidance on next appropriate steps (referral for intervention or further diagnostic procedures)
- 2.
One must thoroughly familiarize oneself with the screening tool, its sensitivity, its specificity, and how it is applicable in one’s particular population
- 3.
No alteration in the order or presentation of the tool must be done to maintain its validity; this includes paying attention to the age range on which the tool is validated and adhering to it
- 4.
There has been no demonstrated advantage of one screening tool over another in a single comparative study between Early Screening of Autistic Traits Questionnaire, Social Communication Questionnaire, Communication and Symbolic Behavior Scales-Developmental Profile, Infant-Toddler Checklist, and key items of the Checklist for Autism in Toddlers
| Tool | Details | How to Obtain |
|---|---|---|
| Modified Checklist for Autism in Toddlers (M-CHAT) a (Robins et al, 2001) | Used in children 16–30 mo old. Available in several different languages. 23 Yes/no response parent questionnaire, completes in 5 min | Free to download and use http://www2.gsu.edu/∼psydlr/DianaLRobins/Official_M-CHAT_website.html |
| Pervasive Developmental Disorders Screening Test-II (PDDST-II) (Siegel, 2004) | Used in children 18–48 mo old. Available in English and Spanish. Stage I also called Primary Care Screener (PCS). 22-item parent report measure, completes in 10–15 min | Purchase from Pearson Assessments http://www.pearsonassessments.com/ $42.50 for the 25 PCS forms |
| Social Communication Questionnaire (SCQ) (Rutter et al, 2003) | Previously known as Autism Screening Questionnaire (ASQ), it is used in children >4 y old. 40 yes/no questions can be completed in 10 min. Available in English and Spanish. More useful as a screener for research projects with parents who already know about ASD symptoms, less useful in young children | Purchase from Western Psychological Services http://portal.wpspublish.com/ $110.00, includes 20 current and 20 lifetime autoscore forms, and manual |
| Childhood Autism Spectrum Test (CAST) (Scott et al, 2002) | Formerly called the Childhood Asperger Syndrome Test. Used in children aged 4–11 y old, also available in various languages. Despite original name, can be used in screening both Asperger and low-functioning children with autism | Free to download and use Autism Research Center http://www.autismresearchcentre.com/tests/cast_test.asp |
| Autism Spectrum Screening Questionnaire (ASSQ) (Ehlers et al, 1999) | Used in children aged 7–16 y. This 27-item checklist, for parents and teachers, takes 10 min to complete. It is designed for screening for symptoms of Asperger disorder (and high-functioning autism) | Available at link but permission from publisher may be necessary |
a M-CHAT has been used extensively in research and clinical practice with sensitivity and specificity demonstrated in the target age range of 16 to 30 months of age. Its validity in those younger than 16 months has not been demonstrated.
Other tools that have been used for screening include the Checklist for Autism in Toddlers (CHAT) and the Screening Test for Autism in Toddlers (STAT). These tools require the clinician to engage in observations and interaction with the child-patient. CHAT is a combined parent report and child observation tool from which the modified CHAT (M-CHAT) was derived. Administered at 18 to 24 months of age, it consists of 14 questions or items and takes about 5 minutes to complete. It now has a revised version called the Quantitative CHAT (Q-CHAT), which is a 25-item parent report on a 5-point scale. Both CHAT and Q-CHAT are freely available for download at http://www.autismresearchcentre.com/ , and are available in English, Spanish, German, and other languages. A highlight of the Q-CHAT is the little cartoon images next to each question demonstrating the type of skill to aid parents in interpretation.
The STAT is a 12-item combined parent report and child observation tool that takes 20 minutes to complete. It requires 2-day training at the TRIAD program at Vanderbilt University (and now through an online tutorial accessed at http://kc.vanderbilt.edu/triad/training/page.aspx?id=1555 ).
While there is no substitute for reading the manual of the tools you are using, there are some online tools that aim to further familiarize pediatricians with autism screening tools. Among these are the online learning modules from the Vermont Interdisciplinary Leadership Education for Health Professionals which, as part of its Autism extension grant, developed several learning modules to aid diverse groups of professionals in screening for autism at early ages. Several tools including M-CHAT, Pervasive Developmental Disorders Screening Test II, and Social Communication Questionnaire (SCQ) have these learning modules in different downloadable formats (Powerpoint, HTML, pdf). These modules, along with other helpful learning resources such as “how to speak to parents before and after screening,” are accessible at their Web site http://www.uvm.edu/∼vtilehp/autism/ .
How early is early screening?
At present, the average reported age of diagnosis for autism is 5.7 years; however, it is recognized that parents or caregivers have suspicions of autism in their children prior to 2 years of age and often by 18 months of age. Evidence shows that early identification leads to early intervention of ASDs and that early intervention is associated with improved outcomes. However, there is a limitation on how early screening and diagnosis can be done reliably. It is difficult to reliably distinguish, before age 1 year, between typical and atypical social, communicative, and behavior characteristics, which are the core constructs of autism. About 1:4 children with ASD have regressive types of symptoms, that is, they had typical or near typical acquisition of developmental milestones, particularly language, and then seemed to lose these around age 18 to 24 months. Therefore, too early screening may lead to a false sense of security if not followed by repeat screening or vigilance after 18 months of age.
Although there have been numerous studies exploring infancy diagnostics, including videotapes and screening questionnaires, they have yet to be proved sufficiently stable to be recommended for use in population-based screening.
The Autism Observation Scale for Infants is a direct interaction, rather than parent report tool, which holds promise for identifying autism from as early as 6 months of age. It is currently being validated in both premature and term populations, but its value in population screening in the office is not yet established.
Similarly, the Communication and Symbolic Behavior Scales (CSBS), particularly the Developmental Profile Infant-Toddler Checklist (CSBS-DP), is a screening tool that can be used with at-risk infants and toddlers older than 6 months, particularly for social and communication skills; however, it is not an ASD-specific screening tool. It can be downloaded for free at http://www.brookespublishing.com/store/books/wetherby-csbsdp/CSBSDP_Checklist.pdf .
While there is no definite ASD screening tool available for infants younger than 15 months, this does not mean that pediatricians do not stay vigilant about autism red flags in this age group. Awareness of red flags ( Table 3 ) and observing these skills, or asking anticipatory guidance questions during well-child visits, may alert the physician to monitor the child more closely.
| Developmental Skill | Typical Age of Acquisition | Child with Autism |
|---|---|---|
| Social smile | Emerges at 6–8 wk old, usually seen by 3 mo | Some children with autism do have smile, but parents’ history make determining typicality of such behaviors difficult (smile elicited by physical contact or anticipatory routine, as opposed to true social smile) |
| Response to name | By 8–10 mo of age, children can respond to their name being called | Children who have autism usually do not, or poorly, respond to name, needing multiple attempts or physical touch. Concerns about hearing loss are often the first alert to caregivers that something is amiss |
| Joint attention (JA) | 8–10 mo following another’s eye gaze; then following a point by 10–12 mo old | No JA, sometimes briefly glances in direction but no return to initiating individual |
| Gesture communication | Gestural pointing, often first to indicate something of need “protoimperative” seen at age 12–14 mo; then “protodeclarative” to draw attention toward an object at 15–16 mo old | No pointing; leading “hand-over-hand,” some extension of hand, but no “3-way pointing” engaging JA with point |
| Babbling | Typical “bilabial babbling” with repetition of baba or dada seen at 6–7 mo old. By 8–10 mo, alternate babbling with silent opportunities to engage caregiver verbal responses At age 10–12 mo, typical “jibber-jabber” or jargon sounds are heard | Usually delayed babbling until beyond age 12 mo. Also, isolated, noncommunicative repetitive sounds are heard before functional communication attempts |
How early is early screening?
At present, the average reported age of diagnosis for autism is 5.7 years; however, it is recognized that parents or caregivers have suspicions of autism in their children prior to 2 years of age and often by 18 months of age. Evidence shows that early identification leads to early intervention of ASDs and that early intervention is associated with improved outcomes. However, there is a limitation on how early screening and diagnosis can be done reliably. It is difficult to reliably distinguish, before age 1 year, between typical and atypical social, communicative, and behavior characteristics, which are the core constructs of autism. About 1:4 children with ASD have regressive types of symptoms, that is, they had typical or near typical acquisition of developmental milestones, particularly language, and then seemed to lose these around age 18 to 24 months. Therefore, too early screening may lead to a false sense of security if not followed by repeat screening or vigilance after 18 months of age.
Although there have been numerous studies exploring infancy diagnostics, including videotapes and screening questionnaires, they have yet to be proved sufficiently stable to be recommended for use in population-based screening.
The Autism Observation Scale for Infants is a direct interaction, rather than parent report tool, which holds promise for identifying autism from as early as 6 months of age. It is currently being validated in both premature and term populations, but its value in population screening in the office is not yet established.
Similarly, the Communication and Symbolic Behavior Scales (CSBS), particularly the Developmental Profile Infant-Toddler Checklist (CSBS-DP), is a screening tool that can be used with at-risk infants and toddlers older than 6 months, particularly for social and communication skills; however, it is not an ASD-specific screening tool. It can be downloaded for free at http://www.brookespublishing.com/store/books/wetherby-csbsdp/CSBSDP_Checklist.pdf .
While there is no definite ASD screening tool available for infants younger than 15 months, this does not mean that pediatricians do not stay vigilant about autism red flags in this age group. Awareness of red flags ( Table 3 ) and observing these skills, or asking anticipatory guidance questions during well-child visits, may alert the physician to monitor the child more closely.
