Draft Recommendation Statement
Autism Spectrum Disorder in Young Children: Screening
This opportunity for public comment expired on August 31, 2015 at 8:00 PM EST
Note: This is a Draft Recommendation Statement. This draft is distributed solely for the purpose of receiving public input. It has not been disseminated otherwise by the USPSTF. The final Recommendation Statement will be developed after careful consideration of the feedback received and will include both the Research Plan and Evidence Review as a basis.
Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.
Draft: Recommendation Summary
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for autism spectrum disorder (ASD) in children for whom no concerns of ASD have been raised by their parents or clinical provider.
See the Clinical Considerations for suggestions for practice regarding the I statement.
ASD is a developmental disorder characterized by persistent and significant impairments in social interaction and communication, restrictive and repetitive behaviors and activities, and presentation at an early developmental age that cannot be accounted for by another condition. The prevalence of ASD in the United States in 2010 was estimated at 14.7 cases per 1,000 children, or 1 in 68 children, with substantial variability in estimates by region, sex, and race/ethnicity.
The USPSTF found adequate evidence that currently available screening tests can detect ASD in children ages 18 to 30 months.
Benefits of Early Detection and Intervention/Treatment
The USPSTF found inadequate direct evidence on the benefits of screening for ASD in toddlers and preschool-age children. There are no studies meeting inclusion criteria of clinical outcomes of children identified with ASD through screening. The USPSTF also found inadequate evidence on the efficacy of treatment of cases of ASD detected through screening. Treatment studies were generally very small, few were randomized trials, most included children who were older than would be identified through screening, and all were in clinically-referred rather than screen-detected patients.
Harms of Early Detection and Intervention/Treatment
The USPSTF found that the harms of screening for ASD and subsequent interventions are small based on evidence about the prevalence, accuracy of screening, and likelihood of minimal harms from behavioral interventions.
The USPSTF concludes that there is insufficient evidence to assess the benefits of screening for ASD in children. Evidence is lacking for the population to be screened, and the balance of benefits and harms cannot be determined.
Draft: Clinical Considerations
This recommendation applies to asymptomatic children who have not been diagnosed with ASD or developmental delay and for whom no concerns of ASD have been raised by their parents or clinical provider.
There are a number of tests available for screening for ASD in children younger than age 30 months. Although there is insufficient evidence to recommend screening with a specific screening tool, the most commonly studied tool is the Modified Checklist for Autism in Toddlers (M-CHAT) and its subsequent revisions (Modified Checklist for Autism in Toddlers with Followup [M-CHAT-F] and Modified Checklist for Autism in Toddlers–Revised, with Followup [MCHAT-R/F]). The MCHAT-R/F is a parent-rated scale, and a positive finding triggers a followup interview. If the followup interview is positive, a full diagnostic workup for ASD is indicated. The screening process assesses communication skills, joint attention, repetitive movement, and pretend play.
Treatment or Interventions
Treatments for ASD include behavioral, medical, educational, allied health, and complementary and alternative medicine approaches.
Suggestions for Practice Regarding the I Statement
Potential Preventable Burden
ASD can cause significant social, communication, and behavioral challenges for affected children and place great strain on family members and other caregivers. Treatment and maturation may reduce the impact of the core symptoms of ASD for some children, but others may experience long-term effects on education, employment, and ability to live independently.1
Although there is limited evidence on the harms of screening for ASD in children, reported potential harms include the time, effort, and anxiety associated with further testing after a positive screening result, particularly if confirmatory testing is delayed because of resource limitations. Behavioral treatments are generally thought to not be associated with significant harms but can place a large time and financial burden on the family. Other treatments for ASD are less well studied and were not included in the scope of this review.
Few data are available regarding the prevalence of screening for ASD by clinicians.
The Centers for Disease Control and Prevention provides Web-based continuing education called “Autism Case Training (ACT)” (available at www.cdc.gov/ncbddd/actearly/autism/case-modules/index.html), as well as other information about ASD (available at www.cdc.gov/ncbddd/autism/index.html).
The M-CHAT screening tool is available online for free at www.mchatscreen.com. Other professional and advocacy organizations have also developed autism toolkits and resources.
The USPSTF's recommendation on screening for speech and language delays and disorders in children age 5 years or younger can be found on its Web site (www.uspreventiveservicestaskforce.org).
Draft: Other Considerations
Research Needs and Gaps
Good-quality studies are needed to better understand the intermediate and long-term health outcomes of screening for ASD in children, and whether earlier identification through screening is associated with clinically important improvements in health outcomes. Studies following large samples of screen-negative children, though resource-intensive, would provide valuable information regarding screening specificity. Treatment studies that enroll younger children, especially those with screen-detected ASD, are critical to understanding the potential benefits of screening.
Burden of Disease
ASD is a developmental disorder characterized by persistent and significant impairments in social interaction and communication, restrictive and repetitive behaviors and activities, and presentation at an early developmental age that cannot be accounted for by another condition. The prevalence of ASD in the United States in 2010 was estimated at 14.7 cases per 1,000 children, or 1 in 68 children, with substantial variability in estimates by region, sex, and race/ethnicity. This represents a 23% increase from 2008; the reasons for this increase are not completely understood.2
Scope of Review
The USPSTF commissioned a systematic review to evaluate the evidence on the accuracy, benefits, and potential harms of brief, formal screening instruments for ASD administered during routine primary care visits, and the benefits and potential harms of early behavioral treatment for children identified with ASD through screening. The review focused on studies of screening in children younger than age 3 years who were unselected (i.e., not identified because of risk factors or concerns regarding ASD).
Accuracy of Screening Tests
There are several available screening tools for ASD, but the strongest and most applicable evidence is for the M-CHAT/F and M-CHAT-R/F, two versions of the same tool. Both use a parent-rated scale that can trigger a followup interview which, if positive, leads to referral for confirmatory diagnosis by a behavioral/developmental specialist. The initial screening process takes 5 to 10 minutes. Two large good-quality trials conducted in the United States in children ages 16 to 30 months found similar positive predictive value for these tools (approximately 50%) for the detection of ASD in unselected populations.3, 4 The validity of these studies was weakened somewhat by the high drop-out rate between screening steps, but is still reasonably high for mass screening. There are no data on the specificity or negative predictive value of these screening tools. One study followed a sample of children who were referred for diagnostic evaluation as a result of screening, but not diagnosed with ASD, and reported that almost all these children had another form of developmental delay.4 It is not known whether early detection of these other problems results in improved health outcomes. Although a number of potential risk factors for ASD have been identified, there is insufficient evidence to determine if certain risk factors modify the performance characteristics of ASD screening tests, such as the age at which screening is performed or other characteristics of the child or family.
Effectiveness of Early Detection and Treatment
The USPSTF found no randomized, controlled trials (RCTs) that directly addressed the overarching question of whether screening for ASD in children age 3 years or younger results in improvements to core ASD symptoms, cognitive and intellectual functioning, language and communication skill development, challenging behavior, adaptive behavior, educational placement/achievement, or quality of life for the child and family.
The USPSTF found 26 good- and fair-quality randomized controlled trials of early intensive behavioral and developmental interventions (the most often studied treatment for this age group) for ASD in young children. Assessment of treatment evidence was complicated by great heterogeneity in the age, type of symptoms, and symptom severity of the children enrolled, and by the variation among studies in intervention design, mode of delivery, comparators, and outcomes measured. Studies were very small (most enrolled between 20 and 40 children) and study quality was generally only fair. Three of four RCTs (including the largest trial of 294 children) reported that early intensive behavioral interventions improved cognitive scores by 11 to 16 points (on the Mullen Scales of Early Learning or the Intelligence Quotient) compared with a range of comparators (calculated from published data).5-7 The fourth RCT found no effect, but this trial compared different modes of delivering the same intervention.8 The same set of studies showed a similar pattern for language outcomes. Twelve RCTs of play- or interaction-based interventions reported significant improvements in some measures of interaction but not others. Other RCTs evaluated various interventions delivered by parents and found inconsistent results.
In addition to the limitations of the evidence in size, study design, and other sources of heterogeneity, it is not clear how applicable these studies are to a screen-detected population. Treatment studies were conducted in populations of children with a previous diagnosis of ASD, many of whom were referred from specialized ASD programs. Many of the children enrolled in the studies had significant impairments in cognition, language, and behavior, and many studies were conducted in an older population than for which the screening tools were developed. In general, children identified through screening rather than through case finding are likely to be younger and possibly less severely affected than those in study populations. It is therefore unclear whether young children with ASD detected by screening and not because of parental or teacher concern will experience similar, or any, benefit.
Potential Harms of Screening and Treatment
The USPSTF found little evidence on the harms of screening and treatment. Potential harms include the time, effort, and anxiety associated with further testing after a positive screening result. This is of particular concern when there is a delay in confirmatory testing because of resource limitations, which are common.1 Behavioral treatments are generally thought to not be associated with significant harms but can place a large time and financial burden on the family. Other treatments for ASD are less well studied and were not included in the scope of this review. The USPSTF concludes that the potential harms of screening and behavioral treatment are no greater than small.
Estimate of Magnitude of Net Benefit
Overall, the USPSTF found insufficient evidence on screening for ASD in asymptomatic children ages 18 to 36 months. The USPSTF identified no studies that directly evaluated the benefits or harms of screening for ASD in this age group. Studies on the benefits and harms of treatment were of small size, few were randomized, and all were conducted in populations that may not represent children who would be detected through screening programs alone. The USPSTF concludes that there is insufficient evidence to assess the balance of benefits and harms of screening for ASD in children.
Draft: Recommendations of Others
The American Academy of Pediatrics’ Bright Futures™ Guidelines recommend universal screening for ASD in all children at ages 18 and 24 months in addition to developmental surveillance and monitoring.9, 10 The American Academy of Neurology and the Child Neurology Society recommend that developmental surveillance should be performed at all well-child visits from infancy through school age, and at any age thereafter if concerns are raised about social acceptance, learning, or behavior. Children failing routine developmental surveillance procedures should be screened for autism using one of the validated instruments (the M-CHAT or Autism Screening Questionnaire).11 The American Academy of Child and Adolescent Psychiatry recommends that the developmental assessment of young children and the psychiatric assessment of all children should routinely include questions about ASD symptomatology.12 The U.K. National Screening Committee does not recommend systematic population screening, citing concerns over the stability of ASD diagnosis at a young age, lack of data on positive predictive value, and weakness of the evidence for the efficacy of treatment.13
1. McPheeters ML, Weitlauf A, Vehorn A, Taylor C, Sathe NA, Krishnaswami S, et al. Screening for Autism Spectrum Disorder in Young Children: A Systematic Evidence Review for the U.S. Preventive Services Task Force. Evidence Synthesis No. 129. AHRQ Publication No. 13-05185-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2015.
2. Centers for Disease Control and Prevention. Prevalence of autism spectrum disorder among children aged 8 years: autism and developmental disabilities monitoring network, 11 sites, United States, 2010. MMWR Surveill Summ. 2014;63(2):1-21.
3. Robins DL, Casagrande K, Barton M, Chen CM, Dumont-Mathieu T, Fein D. Validation of the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F). Pediatrics. 2014;133(1):37-45.
4. Chlebowski C, Robins DL, Barton ML, Fein D. Large-scale use of the Modified Checklist for Autism in low-risk Toddlers. Pediatrics. 2013;131(4):e1121-7.
5. Strain PS, Bovey EH. Randomized, controlled trial of the Leap model of early intervention for young children with autism spectrum disorders. Topics Early Child Spec Educ. 2011;31(3):133-54.
6. Dawson G, Rogers S, Munson J, Smith M, Winter J, Greenson J, et al. Randomized, controlled trial of an intervention for toddlers with autism: the Early Start Denver Model. Pediatrics. 2010;125(1):e17-23.
7. Smith T, Groen AD, Wynn JW. Randomized trial of intensive early intervention for children with pervasive developmental disorder. Am J Ment Retard. 2000;105(4):269-85.
8. Sallows GO, Graupner TD. Intensive behavioral treatment for children with autism: four-year outcome and predictors. Am J Ment Retard. 2005;110(6):417-38.
9. Johnson CP, Myers SM; American Academy of Pediatrics Council on Children With Disabilities. Identification and evaluation of children with autism spectrum disorders. Pediatrics. 2007;120(5):1183-215.
10. Committee on Children With Disabilities. Technical report: the pediatrician’s role in the diagnosis and management of autistic spectrum disorder in children. Pediatrics. 2001;107(5):e85.
11. Filipek PA, Accardo PJ, Ashwal S, Baranek GT, Cook EH Jr, Dawson G, et al. Practice parameter: screening and diagnosis of autism. Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society. Neurology. 2000;55(4):468-79.
12. Volkmar F, Siegel M, Woodbury-Smith M, King B, McCracken J, State M; American Academy of Child and Adolescent Psychiatry (AACAP) Committee on Quality Issues (CQI). Practice parameter for the assessment and treatment of children and adolescents with autism spectrum disorder. J Am Acad Child Adolesc Psychiatry. 2014;53(2):237-57.
13. U.K. National Screening Committee. The U.K. NSC recommendation on autism screening in children. London: U.K. National Screening Committee; 2012. Accessed at http://www.screening.nhs.uk/autism on July 8, 2015.
Internet Citation: Draft Recommendation Statement: Autism Spectrum Disorder in Young Children: Screening. U.S. Preventive Services Task Force. August 2015.