Factor analysis of the self-report version of the strengths and difficulties questionnaire in a sample of children with intellectual disability.
Use the three-factor self-report SDQ, not the five-factor one, when you screen emotional and behavioural problems in kids with ID.
01Research in Context
What this study did
Haynes et al. (2013) ran factor analysis on the self-report SDQ in children with intellectual disability. They wanted to see if the usual five-factor model still fits this group.
They tested both the old five-factor and a new three-factor version. The shorter form groups items into Positive Relationships, Negative Behaviour, and Emotional Competence.
What they found
The three-factor model won. Exploratory and confirmatory tests both said it fits the data better than the five-factor one.
In plain words: kids with ID answer the SDQ in three clear chunks, not five. Keep the shorter form when you screen this population.
How this fits with other research
Maïano et al. (2011) also used confirmatory factor analysis on an ID sample. They found the 6-item physical-self inventory stayed stable across age, gender, and ID level. Both studies show that short, re-factored scales can work well for people with ID.
MacLean et al. (2011) ran a similar CFA on the WAIS-III and got the opposite result: the standard 4-factor IQ model did NOT fit adults with ID. The difference is the tool, not the method. The SDQ is a brief behaviour screener; the WAIS-III is a long IQ test. Short, simple tools survive the ID translation better.
Holburn (1997) warned that small or convenience samples can trick you into the wrong factor structure. Allison’s team avoided that trap by testing both models head-to-head, so their three-factor result is more trustworthy.
Why it matters
If you give the regular five-factor SDQ to a child with ID, the scores may mislead you. Switch to the three-factor version and you get cleaner data for treatment planning. It takes the same 5 minutes to complete, but now the subscales line up with how these kids actually think about their feelings and behaviour. That’s a free upgrade to your screening accuracy.
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02At a glance
03Original abstract
The rate of emotional and behavioural disturbance in children with intellectual disability (ID) is up to four times higher than that of their typically developing peers. It is important to identify these difficulties in children with ID as early as possible to prevent the chronic co-morbidity of ID and psychopathology. Children with ID have traditionally been assessed via proxy reporting, but appropriate and psychometrically rigorous instruments are needed so that children can report on their own emotions and behaviours. In this study, the factor structure of the self-report version of the Strengths and Difficulties Questionnaire (SDQ) was examined in a population of 128 children with ID (mean age=12 years). Exploratory and Confirmatory Factor Analysis showed a three factor model (comprising Positive Relationships, Negative Behaviour and Emotional Competence) to be a better measure than the original five factor SDQ model in this population.
Research in developmental disabilities, 2013 · doi:10.1016/j.ridd.2012.11.008