Publication Highlight: A Scoping Review of Trajectory Research in Children with an Autism Diagnosis

Autism Care



“Future research needs to focus not only on the biological markers of autism but also include data about functioning, participation, and environmental barriers and facilitators.”

Dr. Olaf Kraus de Camargo  //  Developmental Pediatrician


MacART is laying the foundation for creating a systematic way of linking scientific research on autism at McMaster University to clinical practice at McMaster Children’s Hospital.

The physical proximity of McMaster Children’s Hospital, Hamilton Health Sciences, and McMaster University has a number of characteristics that provides the rare opportunity for collaborative research. Taking advantage of existing university and clinical infrastructure and cross-appointments for clinicians at the university, autism experts from these organizations are coming together to integrate autism research into clinical practice.

The focus of MacART members’ research is in the areas of basic science, clinical practice, clinical research, epidemiology and statistical modelling, knowledge translation and exchange, and social science research. By promoting the collaboration of stakeholders across disciplines, MacART is reducing barriers to implementing research in clinical practice, with the goal of advancing autism care through meaningful research.

Learn more about our research HERE.


MacART members are now supervising more than 50 research trainees at the undergraduate, graduate, and postgraduate levels, and are engaged in the mentoring of junior and intermediate faculty members.

In the future, we intend to establish research and clinical training programs for students in McMaster’s undergraduate medical, health sciences, and psychology programs, and for residents and fellows in Pediatrics and Psychiatry.

By training and mentoring emerging researchers and practitioners, we will help to solidify their understanding of and commitment to using basic science to inform their clinical practice, and to use their clinical experience to help formulate research questions. It is our belief that involving these learners in MacART educational activities will promote their use of practices that advance autism care through meaningful research.


“Our scientists are working collaboratively with local clinicians to generate the evidence needed to improve autism services. This symposium is a great example of McMaster’s community engagement efforts.”

Dr. Patrick Deane // President & Vice-Chancellor // McMaster University


The community engagement component of MacART strives to work with stakeholders and involve them as partners in every step of the research process.  By doing so, the questions that drive research begin to change. They become more meaningful because they address the real day-to-day challenges faced by children and their families, and the clinicians supporting them.

MacART aims to increase participation and involvement of members of the McMaster and Hamilton communities in the research process. With community members driving the research, new and relevant knowledge can be produced to bridge the research-to-practice gap in autism and advance autism care through meaningful research.


“People whose lives are connected to the challenge of autism can share knowledge – from clinicians to educators to parents – and what an amazing opportunity that is. We have a real opportunity to translate challenges into research, and research into practice that will help families living with autism.”

Rob MacIsaac  //  President & CEO // Hamilton Health Sciences


Policies should be created using the best available evidence that make positive impacts on the lives of Autistic individuals, along with their families.

MacART’s founder, Stelios Georgiades, serves on both federal and provincial advisory committees about autism supports/service funding. Along with the wide-ranging expertise of its many autism experts, MacART is set to act as a highly credible source of evidence-based information to influence and inform public policy about the provision and funding of autism diagnosis, services, and family supports.

MacART will continue to find ways to collaborate with policymakers to both learn more about the policymaking process, and to contribute our expertise and knowledge to inform policymaking, in order to advance autism care through meaningful research.

Autism research has increasingly called researchers to employ longitudinal trajectory methods (i.e., collecting data at three or more timepoints) to understand different developmental pathways of Autistic people across the lifespan. This area of exploration has been a core focus for many among the MacART team.

According to MacART member Dr. Stephen Gentles, trajectory studies involve measuring developmental or health-related outcomes at three or more timepoints, as opposed to measuring them at two or more timepoints like a more typical cohort study does. “More timepoints allows you to characterize the shape, or ‘changes in the rate of change' of something over time. These have been described as 'turning points’ and you can think of it as an elbow in the slope of something that changes over time,” Dr. Gentles says. “From a parent’s perspective this might be noticed as accelerations, plateaus, or slowdowns in a child’s development.”  In his recently-published review, the team focused on trajectory studies of child development, up to age 18.

This review, titled “Trajectory research in children with an autism diagnosis: A scoping review”, was recently published open access (free) in the journal Autism. MacART collaborators on the study included members Dr. Yun-Ju (Claire) Chen, Dr. Eric Duku, and Dr. Stelios Georgiades.

“We chose to do a scoping review because this methodology is best suited to identify and characterize the wide breadth of published research in an area. Scoping reviews are like systematic reviews in that they feature a systematic search and screening process that aims to comprehensively capture all literature on a topic,” explains Dr. Gentles. “But in contrast to classic systematic reviews, where the aim to summarize the findings of research on a more specific research question, scoping reviews are not considered an appropriate method for summarizing findings. Rather scoping reviewers stick to summarizing other characteristics of the research under review like the methods used, populations and outcomes studied.  They can provide useful ‘maps’ to the available research on a broad topic.”

Trajectory studies have been used to study the progression over time of many different outcomes relevant to autistic child development. Among other things, this review provides a resource guide to the studies and age ranges covered for the ten most-studied outcome domains. These outcome domain summaries may be useful to clinicians, policymakers, and others planning care or services who may want a map of trajectory research available across clinically relevant outcome domains.

“This review will also have broad appeal and usefulness not only for scientific audiences, but also for autistic people and parents or caregivers of autistic children who may want to know where to find the research that will give them answers to questions like, ‘What will my child be like as they get older?’” Dr. Gentles adds. “Anyone who wants to know where to find the research that tells us about the shape of developmental pathways of autistic children will find this review a useful resource. This includes trajectory researchers wanting a complete idea of the research on the outcome domain(s) or methods they may be considering. And systematic reviewers who want to know if there’s enough research to do a more focused review on a specific outcome domain.”

Among the conclusions is a recommendation that future research be planned to address the absence of trajectory studies in low- and middle-income countries, and that researchers consider following outcome domains that caregivers and autistic people consider meaningful when planning their next trajectory studies.

Many kudos to Dr. Stephen Gentles and colleagues for this impactful publication that will help inform future directions in developmental trajectory research for Autistic people across the lifespan!

There is also a podcast interview that Dr. Gentles participated in about this topic!