title: The autism inpatient collection: methods and preliminary sample description.
abstract: BACKGROUND
  Individuals severely affected by autism spectrum disorder (ASD), including those with intellectual disability, expressive language impairment, and/or self-injurious behavior (SIB), are underrepresented in the ASD literature and extant collections of phenotypic and biological data. An understanding of ASD's etiology and subtypes can only be as complete as the studied samples are representative.
  
  
  METHODS
  The Autism Inpatient Collection (AIC) is a multi-site study enrolling children and adolescents with ASD aged 4-20 years admitted to six specialized inpatient psychiatry units. Enrollment began March, 2014, and continues at a rate of over 400 children annually. Measures characterizing adaptive and cognitive functioning, communication, externalizing behaviors, emotion regulation, psychiatric co-morbidity, self-injurious behavior, parent stress, and parent self-efficacy are collected. ASD diagnosis is confirmed by the Autism Diagnostic Observation Schedule - 2 (ADOS-2) and extensive inpatient observation. Biological samples from probands and their biological parents are banked and processed for DNA extraction and creation of lymphoblastoid cell lines.
  
  
  RESULTS
  Sixty-one percent of eligible subjects were enrolled. The first 147 subjects were an average of 12.6 years old (SD 3.42, range 4-20); 26.5 % female; 74.8 % Caucasian, and 81.6 % non-Hispanic/non-Latino. Mean non-verbal intelligence quotient IQ = 70.9 (SD 29.16, range 30-137) and mean adaptive behavior composite score = 55.6 (SD 12.9, range 27-96). A majority of subjects (52.4 %) were non- or minimally verbal. The average Aberrant Behavior Checklist - Irritability Subscale score was 28.6, well above the typical threshold for clinically concerning externalizing behaviors, and 26.5 % of the sample engaged in SIB. Females had more frequent and severe SIB than males.
  
  
  CONCLUSIONS
  Preliminary data indicate that the AIC has a rich representation of the portion of the autism spectrum that is understudied and underrepresented in extant data collections. More than half of the sample is non- or minimally verbal, over 40 % have intellectual disability, and over one quarter exhibit SIB. The AIC is a substantial new resource for study of the full autism spectrum, which will augment existing data on higher-functioning cohorts and facilitate the identification of genetic subtypes and novel treatment targets. The AIC investigators welcome collaborations with other investigators, and access to the AIC phenotypic data and biosamples may be requested through the Simons Foundation (www.sfari.org).
authors.affiliation: Maine Medical Center Research Institute, Spring Harbor Hospital, Tufts University School of Medicine, 123 Andover Road, Westbrook, ME 04092 USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Siegel
authors.affiliation: Maine Medical Center Research Institute, Tufts University School of Medicine, 509 Forest Avenue, Portland, ME 04101 USA.
authors.forename: Kahsi A
authors.initials: KA
authors.lastname: Smith
authors.affiliation: University of Pittsburgh School of Medicine, 3811 O'Hara St, Pittsburgh, PA 15213 USA.
authors.forename: Carla
authors.initials: C
authors.lastname: Mazefsky
authors.affiliation: University of Colorado School of Medicine, Children's Hospital Colorado, 13123 E. 16th Avenue, Aurora, CO 80045 USA.
authors.forename: Robin L
authors.initials: RL
authors.lastname: Gabriels
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH 45229 USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Erickson
authors.affiliation: University of Maryland School of Medicine, Sheppard Pratt Health System, 6501 N. Charles Street, Baltimore, MD 21204 USA.
authors.forename: Desmond
authors.initials: D
authors.lastname: Kaplan
authors.affiliation: Brown University, Lab for Molecular Medicine, 70 Ship Street, Providence, RI USA ; Rhode Island Consortium of Autism Research and Treatment (RI-CART), Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital and Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, 1011 Veteran Memorial Pkwy, East Providence, RI 02915 USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Morrow
authors.affiliation: University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue MLC 4002, Cincinnati, OH 45229 USA.
authors.forename: Logan
authors.initials: L
authors.lastname: Wink
authors.affiliation: Maine Medical Center and Maine Medical Center Research Institute, Tufts University School of Medicine, 66 Bramhall Street, Portland, ME 04102 USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Santangelo
keywords: Autism spectrum disorder; Genetics; Inpatient; Intellectual disability; New data resource; Non-verbal; Psychiatric; Self-injury; Severe autism