A new federally-funded review of thousands of studies finds that there are more than two dozen autism interventions worthy of being called “evidence-based.”

Researchers combed through over 29,000 studies published in peer-reviewed journals between 1990 and 2011 that tested various behavioral, developmental or educational interventions for autism to identify the most meaningful approaches for those with the developmental disorder from birth through age 22.

Ultimately the review, which was funded by the U.S. Department of Education, identified 27 interventions with substantial research backing ranging from cognitive behavioral intervention to exercise, modeling, scripting and use of a picture exchange communication system.

That’s an increase over the 24 interventions considered to be proven in an earlier version of the report that was produced in 2008.

The review, which is often relied on by professionals and parents alike to assess what approaches are worthy of trying is produced by the National Professional Development Center on Autism Spectrum Disorders, a multi-university center housed at the University of North Carolina at Chapel Hill that trains professionals and promotes the use of evidence-based practices with those who have autism.

“Parents often pay for interventions that have no evidence behind them,” Samuel L. Odom of UNC who co-headed the effort. “This report will allow them to make the best choices.”

In order to be deemed an “evidence-based practice,” interventions needed to have backing from at least two group studies conducted by different researchers or at least five studies that collectively included 20 participants or some combination of the two scenarios.

Beyond the 27 interventions that received a stamp of approval, the review also highlighted 24 methods that have some support, but not enough to be considered proven. These included music therapy, theory of mind training and a technique known as sensory diet where various activities are integrated into a child’s routine to meet their sensory needs.

“Some interventions may seem cutting-edge, but we don’t yet know if they have any drawbacks or trade-offs,” said the report’s lead author, Connie Wong of UNC. “Our report only includes what’s tried and true.”