Conclusions We found patchy evidence on reliability and validity , for only a few of the tools used to measure behaviour problems in young children with ASD .
Background Behaviour problems are common in young children with autism spectrum disorder ( ASD ) .
There are many different tools used to measure behavior problems but little is known about their validity for the population .
Objectives To evaluate the measurement properties of behaviour problems tools  used in evaluation of intervention or observational research studies with children with ASD up to the age of six years .
Early intensive behavioral intervention: outcomes for children with autism and their parents after two years.
An intervention group ( n=23 ) of preschool children with autism was identified on the basis of parent preference for early intensive behavioral intervention  and a comparison group ( n=21 ) identified as receiving treatment as usual .  Prospect i ve assessment was undertaken before treatment , after 1 year of treatment , and again after 2 years . Groups did not differ on assessment s at baseline but after 2 years , robust differences favoring intensive behavioral intervention were observed on measures of intelligence , language , daily living skills , positive social behavior , and a statistical measure of best outcome for individual children . Measures of parental well-being , obtained at the same three time points , produced no evidence that behavioral intervention created increased problems for either mothers or fathers of children receiving it
Conclusions We found patchy evidence on reliability and validity , for only a few of the tools used to measure behaviour problems in young children with ASD .
Background Behaviour problems are common in young children with autism spectrum disorder ( ASD ) .
There are many different tools used to measure behavior problems but little is known about their validity for the population .
Objectives To evaluate the measurement properties of behaviour problems tools  used in evaluation of intervention or observational research studies with children with ASD up to the age of six years .