Embrace the Complexity: The US Preventive Services Task Force Recommendation on Screening for Autism Spectrum Disorder

In this issue of JAMA, the US Preventive Services Task Force (USPSTF) presents final recommendations for screening childrenaged18 to30months forautismspectrumdisorder (ASD).1 Autism spectrum disorder canbe responsible for significant, long-term impairment in social interaction, communication, and functional capacity. Emerging evidence suggests that early intensive behavioral therapy has the potential to improveoutcomes.2TheprevalenceofASDhas increased inrecentyearsand isestimatedtobeashighas 1 in68children,3 suggesting that improving long-termoutcomescouldhavesubstantial societal impact. TheUSPSTF reviews topics that focus only onasymptomatic populations and services provided in (or referable from) primary care and makes its recommendations by following a transparent set ofmethodologic processes.4 TheUSPSTFconcluded that, “the current evidence is insufficient to assess the balance of benefits and harms of screening for ASD in young childrenforwhomnoconcernsofASDhavebeenraisedbytheir parents or a clinician”1 andhas given the recommendation an Igrade.The Igradestems fromthesmall sizeandvariablequality of intervention studies and from a lack of direct evidence that screening leads to clinical improvement.1 Although this recommendation may be disappointing to manypeople, theUSPSTFhas appropriately applied itsmethodology to the question of ASD screening and has fulfilled its charge of applying rigorous analysis to the best available evidence. Asking the USPSTF to consider downstream policy or practice ramifications of its decision, or others’ interpretations of it, would be to devalue its critical role as an impartial evaluator of evidence. Professional societies, constituent groups, families, and individual clinicians will need to contextualize the USPSTF’s evaluation within a broader discussiononpolicyandpatientcareandassess,basedonthisbroader context, whether universal ASD screening is warranted. In considering the USPSTF’s recommendation, the issue of “direct evidence” is critical. Although validation studies might prove a screening test to be good at identifying a certaincondition, andseparate interventional studiesmight show improvement in those treated for that condition, this piecemeal analytic frameworkdemonstratesonly the strengthof individual links in a complicated process chain that includes screening, diagnostic evaluation, engagement with treatment, and improved health outcomes. Conversely, higherlevel direct evidence addresses the more overarching question of whether universal screening results in clinical improvement—abroaderanalytic frameworkthatconsiders the process chain in its entirety. Depending on the condition in question and the strength of the contributing research, evidence supporting individual links in a chain may be sufficient toproduceapositive recommendation. In thecaseofASD screening, the USPSTF decided that the evidence was not. Inexplaining thisdecision, theUSPSTFquestionswhether the interventional studies included in their reviewcouldbeextrapolated to a screen-detected population and cites the likelihood that children identified through screening would be youngerandlessseverelyaffectedthantheparticipantsof these studies.1While thismaybeanappropriate justification, it isonly onedimensionof abroaderquestion regarding the level of evidence necessary to demonstrate the value of a clinical process as complicated as screening for, diagnosing, and treating ASD. Autismspectrumdisorder is aheterogeneouscondition.3,5 Its considerable variability in prevalence and age of diagnosis demarcates fault linesof socioeconomicstatus, race,ethnicity, and geography3,6—suggesting both disparities in access to servicesanddivergent, regional culturesofpractice.Thecomplex behavioral interventionsadministeredtochildrenwithASDvary in both content anddelivery, involve a set of clinicians outside the domain of primary care, and produce variable outcomes amongtheheterogeneouspopulationofchildrenwithASD.7At each step along this screening-to-treatment chain are children (and families) who get screened or do not, get diagnosed with ASD or do not, and respond to therapy or do not. This sorting happensbasedonnonrandomfactors, likely (butnotnecessarily)having todowithaccessibilityof services,patient-provider communication,serviceengagement,culturalrelevanceofcare, andhealth literacy.Studyingsuchaprocesschainas individual links ignores these complexities, and it is inadequate to prove, or disprove, the effectiveness of ASD screening. Somecritics of theUSPSTF’sdecisionhaveargued that accumulatingdirect evidence that accounts for all the complexities around diagnostic confirmation and engagement with treatment is prohibitively expensive andnot feasible.8,9While it is important to recognize the challenges involved with accumulating such evidence, the complexity of a clinical problem isno justification for adjusting theUSPSTF’s standards for a positive recommendation. Rather, consistent with the intent of an I statement,10 the currentUSPSTFreport isanopportunitytomotivatebetter,more Related article page 691 Opinion