Factor analysis of the autism spectrum screening questionnaire in a population-based child sample

Abstract

Purpose

The aim of this study was to investigate several possible factor structures of the Autism Spectrum Screening Questionnaire (ASSQ).

Materials and methods

We used the 27-item screening tool for school-aged children in a general population of 8-year-old children (n = 3,538) and compared the occurring solutions to previously published factor models.

Results

A one-factor solution and a four-factor solution were identified in Exploratory Factor Analysis (EFA) and confirmed with Confirmatory Factor Analysis (CFA), while two-, three-, five- and six-factor solutions were rejected. In CFA, our four-factor solution showed the best goodness-of-fit indexes when compared with factor models previously presented by Posserud et al. and Ehlers et al.

Conclusions

The results indicate a strong underlying connection between all ASSQ items which is elicited by the one-factor solution. Although as a screening tool, ASSQ is functioning with the unifactorial solution, the four factors can help to identify certain clusters of autism spectrum traits.

Keywords:

• ASD
• autism spectrum
• autism spectrum screening questionnaire
• ASSQ
• factor analysis

Acknowledgements

We are grateful to child psychiatrist, Docent Sirkka-Liisa Linna, M.D., who gave her expertise to the diagnostic process and to Professor Emerita Irma Moilanen, M.D., for support and help. This study will be adapted into the dissertation of the first author. We warmly thank the thousands of children and their parents for making the study possible and the hundreds of schools and trustworthy and cooperative teachers for their help in collecting the data.

Ethical approval

The collection of the data used in this study was approved by the Ethical Committee of the Northern Ostrobothnia Hospital District in 05.02.1999.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data that support the findings of this study are available from the corresponding author, [JM], upon reasonable request.

Additional information

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of the present article: This work was funded by The Alma and K. A. Snellman Foundation, Oulu, Finland and by The Finnish Brain Association.