Trajectory research in children on the autism spectrum: a scoping review protocol

Abstract

IntroductionLongitudinal trajectory methods, featuring outcome assessments at three or more time points, are increasingly being used as appropriate approaches to understand developmental pathways of people on the autism spectrum across the lifespan. Understanding the scope of this rapidly expanding body of research can help inform future trajectory studies and identify areas for potential meta-analysis as well as key evidence gaps. We present the protocol for a scoping review whose objective is to identify and summarise the scope of research that uses a longitudinal trajectory study design to examine development in children diagnosed with autism. Specifically, we will identify outcome domains and age intervals that have been well characterised, areas where further research is needed and the historical use of various longitudinal trajectory analytical approaches.Methods and analysisWe outline the methods for the proposed scoping review according to the framework outlined by Arksey and O’Malley, with subsequent clarifications and enhancements by other authors. Using a search strategy developed by a medical librarian, we will search six databases for relevant publications. Titles and abstracts will be screened in duplicate, followed by full-text screening. Data extraction fields developed predominantly a priori from a set of guiding subquestions will be used to chart relevant data. The findings will include quantitative aggregate summaries, narrative summaries, and appraisal of trajectory studies according to our methodological subquestions. We will consult autistic self-advocate and parent–caregiver stakeholders to facilitate interpretation of the findings.Ethics and disseminationResearch ethics approval is not required for this scoping review. The results will be presented to researcher, care professional, policy-maker and stakeholder audiences at local and international conferences, other dissemination activities and published in a peer-reviewed journal.

Trajectory research in children with an autism diagnosis: A scoping review

“…We had hypothesized that studies employing group-based approaches would less often feature comparisons to children not on the autism spectrum (i.e. by focusing on within-autism heterogeneity) and would have higher sample sizes, compared to studies employing non-group-based approaches (GCM- or traditional-type) ( Gentles et al, 2021 ). The type of analytic approach employed varied significantly by whether studies included comparisons to children not on the autism spectrum (χ 2 (2) = 7.016, p = 0.030) – only 17% (3/18) of studies employing group-based approaches featured comparisons to children not on the autism spectrum, compared to 50% (38/76) of studies not employing group-based approaches (GCM- or traditional-type) and 56% (5/9) mixed-approach studies.…”

“…The following 12 exclusion criteria, in five areas, were used during screening. We used a set of sub-questions to determine the fields to include in the data extraction form (developed in Microsoft Word), as described previously (Gentles et al, 2021). Data from included articles were extracted individually by one of the four reviewers and verified by the review coordinator.…”

“…We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR; Tricco et al, 2018 ). The protocol for this review, which contains some additional detail of the planned methods, is published open access ( Gentles et al, 2021 ).…”

“…Data from included articles were extracted individually by one of the four reviewers and verified by the review coordinator. Deviations from the published protocol ( Gentles et al, 2021 ) in terms of what was extracted are described here. While we initially expected trajectory results to be presented with reference to child age, this was not the case for all studies; we therefore extracted information about whether trajectory assessments and results were age-referenced or not.…”

“…employment status, romantic relationships), however, differs from those relevant to child development (including functional and educational domains). Separate attention to characterizing trajectory research in children on the autism spectrum is warranted to summarize areas where research has been conducted and highlight where gaps still exist ( Gentles et al, 2021 ). We are unaware of prior reviews characterizing the available research employing a trajectory design to study change in outcome domains over time in children on the autism spectrum.…”