Screening for Autism Spectrum Disorders among 16 Months to 30 Months Old Children in a Tertiary Care Hospital, South India

Introduction: Autism Spectrum Disorders (ASDs) are neuro-developmental disorders characterised by persistentimpairment in reciprocal social communication and repetitive patterns of behaviour.Objectives: To screen for ASDs in children aged 16 to 30 months using M-CHAT-F (Modified Checklist for Autismin Toddlers- Follow up) to estimate the prevalence of ASDs and to evaluate the factors associated with ASDs.Method: Children aged 16 to 30 months were randomly screened for ASDs with MCHAT-F. Children who met theDSM-5 diagnostic criteria were labelled autistic and rest was followed up. Two controls for each case were selectedrandomly among the subjects who were screen negative.Results: Nine hundred and twenty children were screened. Among them, 508(55.2%) children were boys and412(44.8%) children were girls. Out of the 920 screened, 38(4.1%) children failed M-CHAT. Out of the 38, 12 (1.3%)children continued to fail in M-CHAT/F and were “M-CHAT screen positive”. The mean age at diagnosis of ASDwas 24±4.6 months. Prevalence of ASD in our setting was 1 in 102 and the male: female ratio was 8:1. The positivepredictive value of M-CHAT-F was 75%. The average score on M-CHAT was 6.33 among ASD and 0.5 amongcontrol. Males, lack of exclusive breast feeding and excessive screen time were found to be factors associated withASDs.Conclusion: The prevalence of ASDs is high. The M-CHAT/F is an effective screening instrument for ASDs.