Diagnostic procedures in autism spectrum disorders: a systematic literature review

Abstract

At present, 'gold standard' diagnosis of autism spectrum disorders (ASD) is a lengthy and time consuming process that requires suitably qualified multi-disciplinary team (MDT) personnel to assess behavioural, historical, and parent-report information to determine a diagnosis. A number of different tools have been developed to assist in determination. To optimise the diagnostic procedures, the best diagnostic instruments need to be identified. This study is a systematic review addressing the accuracy, reliability, validity and utility of reported diagnostic tools and assessments. To be included in this review, studies must have (1) identified an ASD diagnostic tool; (2) investigated either diagnostic procedure or the tools or personnel required; (3) be presented in English; (4) be conducted in the Western world; (5) be one of three types of studies [adapted from Samtani et al. in Cochrane Database Syst Rev 3:1-13, 2011], viz. (a) cohort studies or cross-sectional studies, (b) randomised studies of test accuracy, (c) case-control studies. MEDLINE, PsychINFO, Scopus, EMBASE, and Cochrane Library databases were scrutinised for relevant literature published from 2000 inclusive on 20th January 2012. In total, 68 articles were included. 17 tools were assessed. However, many lacked an evidence base of high quality-independent studies. The Autism Diagnostic Interview-Revised (ADI-R) and Autism Diagnostic Observation Schedule (ADOS) stood out with the largest evidence base and highest sensitivity and specificity. When the ADI-R and ADOS were used in combination they revealed levels of accuracy very similar to the correct classification rates for the current 'gold standard' diagnostic procedure viz. 80.8% for ASD. There is scope for future studies on the use of the ADI-R and ADOS in combination.

Prospective assessment of autism traits in children exposed to antiepileptic drugs during pregnancy

“…The prevalence of autism traits in the Australian population when using the CARS is not known, so one interpretation of our findings is that our data simply reflect a greater sensitivity to ASD but poor specificity or poor diagnostic accuracy as a result of using this instrument in all cases. A recent systematic review of diagnostic and screening instruments for autism noted that any instrument with a diagnostic accuracy of 80% or greater is equivalent to the "gold standard" of multi-disciplinary team diagnoses 36 ; the CARS exceeds this threshold and has excellent levels of sensitivity and specificity. Thus, the current data raise the concern that many children exposed to AEDs in utero have undetected neurodevelopmental problems.…”

High use of complementary and alternative medication among children with autism is not associated with the severity of core symptoms

“…In comparison, previous research relied on parental report to obtain information on the original diagnosis of autism [13,17,42], thus it is subject to recall bias. Therefore, the current study's data collection methods on the diagnosis and severity of autism might be viewed as more accurate given that the ADOS, an assessment that has high specificity and sensitivity for diagnosing ASD [43], was administered upon entry into this study. Around one-quarter of the children in the current study, all of whom had a clinical diagnosis of ASD, did not reach ASD criteria according to the ADOS.…”

Screening instruments in child and adolescent psychiatry: general and methodological considerations

“…These mainly non-mental health professionals need screening instruments to detect whether or not a child is in need for a general psychiatric evaluation (caseness) and, in the event that a specific psychiatric disorder is assumed, screeners for a particular disorder (e.g., ADHD, psychosis). Furthermore, even mental health professionals are in need for screens, if specialized, elaborate/sophisticated and/or time-consuming assessments are considered, e.g., for psychosis risk or autism [7,9,10].…”