Unmasking Autism in Adults: A Global Systematic Review and Meta-Regression of Prevalence, Misdiagnosis, and Predictive Factors

This protocol outlines a systematic review focused on adult Autism Spectrum Disorder (ASD) diagnosis and intervention outcomes across global healthcare systems. The review includes studies involving individuals diagnosed with ASD using recognized criteria such as DSM-5 or ICD-11, with emphasis on prevalence, screening procedures, and therapeutic effectiveness. Eligible interventions span pharmacological and non-pharmacological approaches, including cognitive behavioral therapy, occupational therapy, digital health tools, and caregiver support programs.Comparative analyses will explore early versus late diagnosis, disparities in healthcare access, and the impact of socioeconomic and cultural factors on care delivery. Both randomized and nonrandomized study designs are included, encompassing RCTs, cohort studies, qualitative research, and meta-analyses. Studies conducted in diverse contexts—urban and rural, public and private systems, and across income levels—will be synthesized to assess equity and systemic barriers.Exclusion criteria apply to studies lacking ASD-specific analysis, non-peer-reviewed literature, and research outside healthcare or educational domains. This protocol is registered in PROSPERO (ID: CRD420251090099) and shared publicly to promote transparency, collaboration, and methodological rigor prior to data extraction and synthesis.