Developing the Inclen Appropriateness Criteria for Autism Spectrum Disorder (INAC-ASD) and Attention Deficit Hyperactivity Disorder (INAC- ADHD)

Background:  Autism [Pervasive Developmental Disorder (PDD) or Autism Spectrum disorder (ASD)] and Attention Deficit/Hyperactivity Disorder (ADHD) have been widely recognized for many decades. Yet there are no socio culturally appropriate diagnostic criteria available, as the construct continue to evolve.

Objectives: This study aimed to develop and validate appropriateness criteria for Autism Spectrum Disorders (ASD) and ADHD that can be applied in resource constraint environment.  

Methods: An international multidisciplinary group of experts met at two face-to-face consensus meetings and reviewed the appropriateness of the current definitions as well as diagnostic criteria in the Indian context and developed the INCLEN Appropriateness Criteria: Autism Spectrum Disorder (INAC-ASD) and INCLEN Appropriateness Criteria -Attention Deficit Hyperactivity Disorder (INAC- ADHD). The INAC-ASD and INAC-ADHD criteria were based on DSM-IV-TR. The study was conducted on children aged 2-9 years by systematic random selection at the general pediatrics out-patient clinics of four tertiary care pediatric facilities. The selected subjects were administered the survey tool-kits by trained psychologists and their performance compared to other widely used tool [Childhood autism rating scale (CARS) for  ASD and Conner’s for (ADHD)] and validated through  independent testing by a team of expert child psychologists and pediatric neurologists (Team diagnosis). The team diagnosis was taken as the reference standard.

Results: The overall diagnostic accuracy for ‘PDD group’ [AUC=0.97 (95% CI=0.93-0.99),z=32.12; P=0.0001], and various accuracy parameters for diagnosing ‘PDD group’ and autism compared with the reference standard of DSM-IV-TR was high (Sn=98%, Sp=95%, PPV=91%, NPV=99%, +LR=20, -LR=0.02) and (Sn=90%, Sp=95%, PPV=90%, NPV=81%, +LR=10, -LR=0.05 respectively). The concordance rate between the INAC-ASD and DSM-IV-TR for ‘PDD group’ was 82.52% [Cohen’s κ=0.89 (95%CI=0.82 to 0.97); P=0.001]. Similarly, concordance rate between the INAC-ADHD and DSM-IV-R diagnosis of ADHD was 71.82% [Cohen’s κ=0.45 (95%CI=0.32 to 0.58); P=0.001]. The overall diagnostic accuracy for INAC- ADHD cut-off score of ≥ 8 [AUC=0.98 (95% CI=0.94-0.99), z=67.02; P=0.0001], and various diagnostic accuracy parameters for differentiating ADHD from those with other neuro-developmental disorders (Sn=87.7%, Sp=42.9%, PPV=58.1%, NPV=79.4%, +LR=1.5, -LR=0.28)and normal children (Sn=87.7%, Sp=97.2%, PPV=98.0%, NPV=83.3%, +LR=31.5, -LR=0.12) as compared with the reference standard of DSM-IV-TR was high. The internal consistency of INAC-ASD and INAC ADHD was 0.96 and 0.91 respectively. The convergent validity with CARS (r = 0.73, P= 0.001) and divergent validity with Binet-Kamat Test of intelligence was (r = -0.37; P=0.004) for INAC-ASD and the convergent validity with Conner’s 3 Parents Scale was moderate (r = 0.73, P= 0.001) for INAC-ADHD.

Conclusions: With the appropriateness of the international criteria for ASD and ADHD being documented in India, INAC-ASD and INAC-ADHD , socio-culturally appropriate tools could be used by clinicians to provide a consistent diagnostic approach and researchers to develop as well as validate intervention measures in India and similar settings elsewhere in the world.