Table 1.

Study eligibility criteria according to PICOS framework.

PICOS element	Inclusion criteria	Exclusion criteria
Population	Children and adolescents aged 3–18 years with clinical ASD diagnosis (DSM-IV, DSM-5, or ICD-10); IQ not specified as exclusion criterion	Participants with severe comorbid neurological conditions (e.g., epilepsy requiring frequent medication adjustment); studies exclusively targeting adults
Intervention	Visual art-based interventions including drawing, painting, sculpture, collage, or multimodal visual arts; minimum duration of 4 weeks	Music therapy alone, drama therapy alone, dance/movement therapy, or combined interventions in which the visual art component cannot be isolated or is not the central activity
Comparison	Treatment-as-usual, waitlist control, no intervention, typically developing comparison groups, or pre-post comparison where controlled designs were unavailable	Studies comparing two active art-based treatments without a control condition
Outcomes	Emotional intelligence or component constructs measured using validated instruments; performance-based assessments, self-report measures, or informant-report instruments accepted	Non-validated measures; behavioral observations without standardized coding
Study Design	Randomized controlled trials or quasi-experimental designs with pre-post assessment; single-arm pre-post designs eligible only where controlled evidence was unavailable and pre and post-intervention statistics were reported	Case reports (n < 5), qualitative research, studies with insufficient statistical data for effect size calculation, and uncontrolled studies that did not report the statistics needed to compute a within-group effect size