The development of a brief screener for autism using item response theory

Mårland, C., Lubke, G., Degl’Innocenti, A., Råstam, M., Gillberg, C. , Nilsson, T. and Lundström, S. (2019) The development of a brief screener for autism using item response theory. BMC Psychiatry, 19, 337. (doi: 10.1186/s12888-019-2333-y) (PMID:31684913) (PMCID:PMC6829932)

Abstract

Background: Brief screening instruments focusing on autism spectrum disorder (ASD) that can be administered in primary care are scarce; there is a need for shorter and more precise instruments. The Autism–Tics, AD/HD and other Comorbidities inventory (A-TAC) has previously been validated for ASD reporting excellent validity. This study aims to determine the psychometric properties of each item in the ASD domain (17 items) in the A–TAC using item response theory (IRT), and thereby construct and validate a short form that could be used as a screening instrument in the general population. Methods: Since 2004, parents of all 9-year-old Swedish twins have been invited to participate in a telephone interview in the Child and Adolescent Twin Study in Sweden (CATSS). The CATSS is linked to the National Patient Register (NPR), which includes data from in- and outpatient care. Data on ASD (A-TAC) collected in CATSS were compared with diagnoses from the NPR. Diagnoses that had been made both before (previous validity) and after (predictive validity) the interviews were included. The sample was divided into a developmental sample and a validation sample. An IRT model was fitted to the developmental sample and item parameters were used to select a subset of items for the short form. The performance of the proposed short form was examined in the validation sample by the use of receiver operation characteristic curves. Results: Four items which were able to discriminate among individuals with more autism traits were deemed sufficient for use in the short form. The values of the area under the receiver operating characteristic curve for a clinical diagnosis of ASD was .95 (previous validity) and .72 (predictive validity). Conclusions: The proposed short form with 4 out of the original 17 items from A-TAC, showed excellent previous validity while the predictive validity was fair. The validity of the short form was in agreement with previous validations of the full ASD domain. The short form can be a valuable screening instrument in primary care settings in order to identify individuals in need for further assessment and for use in epidemiological studies.

• Item Type: Articles
• Additional Information: The Child and Adolescent Twin Study in Sweden study was supported by the Swedish Council for Working Life, funds under the ALF agreement, the Söderström-Königska Foundation and Swedish Research Council (Medicine, Humanities and Social Science) Grant number: 2017–02552. Funding was also received from AnnMari and Per Ahlqvist Foundation and Birgit and Sten A Olsson.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gillberg, Professor Christopher
• Authors: Mårland, C., Lubke, G., Degl’Innocenti, A., Råstam, M., Gillberg, C., Nilsson, T., and Lundström, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Mental Health and Wellbeing
• Journal Name: BMC Psychiatry
• Publisher: BMC
• ISSN: 1471-244X
• ISSN (Online): 1471-244X
• Published Online: 04 November 2019
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in BMC Psychiatry 19:337
• Publisher Policy: Reproduced under a Creative Commons License