The Griffiths Autism Early Screening (GAES): A Novel Developmental Test for Screening Autism Spectrum Disorder

This study was undertaken to set a novel developmental screening test for autism spectrum disorder (ASD) using the Griffiths Scales of Child Development (Griffith III), in order to intercept the early atypical developmental patterns indicating ASD risk in the first three years of age. An observational and interactive ASD screener, the Griffiths Autism Early Screening (GAES), was developed by detecting Griffiths III items differentiating toddlers with ASD risk from those with global developmental delay (DD) or neurotypical development. The GAES was validated with ASD-specific diagnostic instruments (ADOS-2) and the cut-off score based on sensitivity, specificity and positive predictive value that best differentiates between ASD and non-ASD children was identified. We enrolled a total sample of 297 subjects, including children at risk for ASD or DD and neurotypical children. At a cut-off score of 12.5, the GAES had a sensitivity of 93%, specificity of 98.4%, positive predictive value of 96.3% and negative predictive value of 96.9% for identifying children at risk for ASD from non-ASD participants (DD/neurotypical children). The GAES total score correlated significantly with the ADOS-2 calibrated severity scores (CSS) (R = 0.53, p < 0.001). Three ASD risk ranges were identified according to GAES total and ADOS-2 CSS: Little-to-no risk (CSS: 1–3, GAES: 1–7); Mild-to-moderate risk (CSS: 4–5, GAES: 8–14); Moderate-to-severe risk (CSS: 6–10, GAES ≥ 15). The GAES provides a direct approach based on developmental profiles to stratify risk for ASD in early childhood ensuring at risk children the most appropriate diagnostic procedures and targeted intervention.