Objective: To assess the sensitivity and specificity of decreased response to name at age 12 months as a screen for autism spectrum disorders (ASD) and other developmental delays.
Design: Prospective, longitudinal design studying infants at risk for ASD.
Setting: Research laboratory at university medical center.
Participants: Infants at risk for autism (55 six-month-olds, 101 twelve-month-olds) and a control group at no known risk (43 six-month-olds, 46 twelve-month-olds). To date, 46 at-risk infants and 25 control infants have been followed up to 24 months. Intervention Experimental task eliciting response-to-name behavior.
Main outcome measures: Autism Diagnostic Observation Schedule, Mullen Scales of Early Learning.
Results: At age 6 months, there was a nonsignificant trend for control infants to require a fewer number of calls to respond to name than infants at risk for autism. At age 12 months, 100% of infants in the control group "passed," responding on the first or second name call, while 86% in the at-risk group did. Three fourths of children who failed the task were identified with developmental problems at age 24 months. Specificity of failing to respond to name was 0.89 for ASD and 0.94 for any developmental delay. Sensitivity was 0.50 for ASD and 0.39 for any developmental delay.
Conclusions: Failure to respond to name by age 12 months is highly suggestive of developmental abnormality but does not identify all children at risk for developmental problems. Lack of responding to name is not universal among infants later diagnosed with ASD and/or other developmental delays. Poor response to name may be a trait of the broader autism phenotype in infancy.