title: Development of Two Dimensional Measures of Restricted and Repetitive Behavior in Parents and Children.
abstract: Restricted and repetitive behaviors (RRBs) are a heterogeneous set of behaviors common across a wide range of neurodevelopmental disorders (NDDs) and neuropsychiatric disorders (NPDs) that extend well into the general population. This study introduces 2 dimensional measurements of RRBs for use in typical and clinical populations from infancy to adulthood.
  
  
  
  The Childhood Routines Inventory-Revised (CRI-R) and the Adult Routines Inventory (ARI) were created and administered online to a nationally representative cohort of 3,108 parents with 3,032 children (range 12 months to 17 years 11 months). Twenty-six percent of children and 36% of adults had at least 1 NDD or NPD.
  
  
  
  Principal axis factoring exploratory analysis showed a 2-factor structure for the 2 instruments (motor behaviors/compulsions and rigidity/insistence on sameness). Analyses for convergent and discriminant validity, internal consistency (Cronbach α ≥ 0.94), and test-retest reliability (r ≥ 0.87) indicated strong psychometric properties. Item response theory analyses indicated strong reliability across the score range for the 2 instruments. RRB rates varied across development, peaking between the preschool and school years. Children with NDDs or NPDs (particularly those with autism spectrum disorder, schizophrenia/bipolar disorder, or obsessive-compulsive disorder/tic disorders) had increased RRBs compared with those with no diagnosis. Parent-child (0.69-0.84) and sibling-sibling (0.76-0.87) intraclass correlations indicated high heritability. Children of parents with an NDD or an NPD exhibited more RRBs compared with children of parents without NDDs or NPDs.
  
  
  
  The CRI-R and ARI are open-source instruments with excellent psychometric properties and will be useful for developmental, clinical, and family genetic studies and for the identification of prodromal conditions involving RRBs.
authors.affiliation: Bucknell University, Lewisburg, PA. Electronic address: dwevans@bucknell.edu.
authors.forename: David W
authors.initials: DW
authors.lastname: Evans
authors.affiliation: Olga Tennison Autism Research Centre, Cooperative Research Centre for Living with Autism (Autism CRC), School of Psychology and Public Health, La Trobe University, Victoria, Australia.
authors.forename: Mirko
authors.initials: M
authors.lastname: Uljarević
authors.affiliation: Geisinger-Bucknell Autism and Developmental Medicine Institute, Lewisburg, PA.
authors.forename: Laina G
authors.initials: LG
authors.lastname: Lusk
authors.affiliation: Institute of Psychiatry, Psychology and Neuroscience and the Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
authors.forename: Eva
authors.initials: E
authors.lastname: Loth
authors.affiliation: Cleveland Clinic Children's Hospital Center for Pediatric Behavioral Health, Cleveland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frazier
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D016241:Child of Impaired Parents / Q000706:statistics & numerical data*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D065886:Neurodevelopmental Disorders / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D019956:Stereotypic Movement Disorder / Q000453:epidemiology*
keywords: dimensional assessment; parents and children; repetitive behavior