Restricted and Repetitive Behavior As Predictors of Diagnosis and Clinician Confidence in Toddlers at Risk of ASD

Background:  A wide range of restricted and repetitive patterns of behaviors (RRBs) has been consistently reported among the earliest infant predictors of a later Autism Spectrum Disorder (ASD) diagnosis (Ozonoff et al., 2008; Wolff et al., 2014).  However, it has also been suggested that RRBs may develop later, and may not be a good predictor of differential diagnosis in young children (Young, 2007).  Furthermore, the relationship between RRBs and clinical judgements regarding diagnosis of ASD in young children (i.e., < 3 years) has not been explored.  Here we examined the role of RRBs in the confidence expressed by clinicians when making judgements of a child’s diagnosis, and also in the final diagnostic status of the child following assessment.  We were interested in whether or not observed and parent reported RRBs predicted clinicians’ confidence in their diagnostic judgements, and also diagnostic status, independently of child characteristics (e.g., age, gender, SES, adaptive functioning), and in particular social communication.

Objectives:  Our aim was to examine the relationship between RRBs, diagnosis of ASD, and clinicians’ confidence in their judgments regarding diagnosis.  Specifically, we examined both the ADOS-2 RRB score and the parent reported ASRS Unusual Behaviors and Behavioral Rigidity subscales on a) clinicians’ confidence in their judgments of diagnosis, and b) final diagnostic status, controlling for demographic variables such as age, gender, socioeconomic status, and child characteristics such as developmental level and adaptive functioning.

Methods:  Participants were 125 children aged under 14-39 months (M = 28.62, SD =5.41) who presented for screening at a Midwestern hospital child development center due to developmental concerns.  Screening clinicians were asked whether or not they thought the child would receive a diagnosis of ASD.  A Likert scale was used to generate a confidence score.  Diagnostic status and assessment results were retrieved from medical record review.

Results:  Correlational analysis were first used to explore the association between diagnosis (ASD, non-ASD), clinician confidence, and relevant variables. Diagnosis was significantly correlated with ADOS-2 RRBs, r(89) = .70, p < .001, but not ASRS Unusual Behaviors, r(66) = .08, p > .05, or Behavioral Rigidity, r(66) = .14, p > .05.  Clinicians’ confidence was significantly associated with ADOS-2 RRBs, r(89) = .32, p = .002, ASRS Unusual Behaviors, r(66) = .34, p = .005, and Behavioral Rigidity, r(66) = .29, p = .017.  Regression analysis identified both ADOS-2 SA, t = 2.55, p = .013, β = .335, and RRBs, t = 2.14, p = .036, β = .249, as significant predictors of diagnosis, however only ADOS-2 RRBs independently predicted clinicians’ confidence, t = 3.35, p = .002, β = .492. 

Conclusions:  Neither parent reported unusual behaviour nor behavioural rigidity was found to be associated with diagnosis of ASD and was not an independent predictor of clinicians’ confidence in their diagnostic judgements.  Of interest, however, the ADOS-2 RRB scale was identified as a predictor of both diagnosis and, moreover, was the only independent predictor of clinicians’ confidence.