Evidence Synthesis: Outcome Measures for Early Intervention Studies in ASD

Background: One problem for researchers evaluating early intervention, and for providers of services for young children with autism spectrum disorder (ASD), is the multitude of outcomes assessed and tools used to measure children’s progress.  How can we best decide what outcomes to measure and how to measure them?

Objectives: To synthesise the evidence about tools used to measure outcomes in children with ASD up to age 6.  Further, to explore how to identify what outcomes to prioritise, and report outcome areas in which robust tools are lacking.

Methods: A number of steps were completed as part of evidence synthesis:

A: Recent summary papers about outcome measurement for young children with ASD were reviewed.

B: Ways of working towards defining a core outcome set for early intervention studies in ASD were reviewed.

C: The methods and findings of the MeASURe review (McConachie et al 2015) were considered. MeASURe identified tools used in ASD early intervention and longitudinal studies, and systematically reviewed papers addressing the measurement properties of the tools when used with young children with ASD, using the COSMIN checklist (Consensus-based Standards for the selection of health Measurement Instruments).

D: Synthesis of evidence and identification of gaps in the tools available to measure outcomes.  

Results: Recent papers have considered the ‘best’ tools for measurement of repetitive behaviours, anxiety and social-communication, usually by expert consensus. Others proposed batteries of tests. No fully systematic process for identifying how best to measure outcomes has been agreed.

Conceptual frameworks for deciding what to measure have been proposed,  based on the International Classification of Functioning, Disability and Health, including domains of ‘impairments’, ‘activity limitations’, ‘participation restrictions’, and family measures.  Ways of integrating the differing perspectives of the autism community, clinicians, educators and researchers have been proposed.

In the MeASURe review, 129 tools were identified. 2,793 papers on the measurement properties of tools were sifted and data extracted from 128 concerning 52 (40%) tools; for 60%, no measurement properties study including children with ASD was found.  The most robust 12 tools were identified, and gaps in the evidence and array of tools pinpointed, such as measurement of wellbeing and participation outcomes for children. The lack of a reliable and valid tool to measure core autism impairments, with proven responsiveness to treatment, is a clear hindrance to early intervention research.

Conclusions: An agreed core set of outcomes, and battery of robust tools, are goals for the future; in the interim a process for reaching such conclusions could be agreed.  For some important outcome areas, good tools are lacking. Further review of established and newer tools is still required, with input from parents and other stakeholders, before consensus can be reached about a recommended battery to be used by researchers and service providers.  

This presentation includes evidence synthesis commissioned by the National Institute for Health Research (NIHR) under the Health Technology Assessment programme (HTA Project:11/22/03). The views expressed are those of the author and not necessarily those of the National Health Service, NIHR or Department of Health.