A review based prevalence of autism spectrum disorder

Pages: 836-846
Bappaditya Adak (Gangadharpur Mahavidyamandir, Howrah, Kolkata)

The prevalence of Autism Spectrum disorder has increased rapidly worldwide in the last few years. However most of the estimation comes from developed regions specifically western countries. There are no reliable and consistent data from non-western or non-affluent countries. The primary objective of the review is to synthesise the results of wide range of published studies to estimate prevalence of ASD with respect to gender and socio-economic status (SES). Secondly, available studies are analysed with identified themes for assessing the significant trends. Based on pre-defined inclusion and exclusion criteria published papers were identified by online search and relevant papers were included published during the time period 2005 to 2015. 27 studies were finally identified for review of which 22 estimated Autism Spectrum Disorder (ASD) or Pervasive developmental disorder (PDD) and 4 concentrated on typical Autism. Overall mean age of study samples ranged between ages 2-17 years. International classification of disabilities (ICD)-9 and 10 criteria as well as Diagnostic Statistical Manual (DSM)-III and IV criteria were retained for diagnostic assessment. The average prevalence of these twenty-seven studies was 91.92 per 10,000 populations. The reported prevalence of ASD varied substantially by country and continent, use of methodology, assessment tools, gender, geographic region and Socioeconomic status (SES). Recent studies provided higher estimation and prevalence rate in developed or much affluent countries as well as urban areas. Also, Parental high SES was found positively associated with prevalence of ASD. Analyses suggest need for accessible and standardized instruments and awareness. Also, more population based investigations is needed in rural as well as developing countries for revealing clear picture of ASD.