The Validation of a New Measure for Assessing the Frequency and Impact of Sensory Sensitivities in Autism, the Sensory Processing Behaviour Questionnaire, and Its Association with Anxiety Symptoms

Background:  

Sensory sensitivities are included in the DSM-5 criteria for autism yet there are few well-validated measures to assess them. A newly developed scale, the Sensory Processing Behaviour Questionnaire (SPBQ: Green, 2013) has been uniquely designed to measure the frequency (e.g., ‘How often have you noticed your child show an unusual response to bright lights in the last month?’) and impact (‘How much of a problem is it?’) of 25 sensory behaviours in multiple domains. Evidence suggests that sensory sensitivities are closely associated with anxiety in autism. The DSM-5 specifies several different types of anxiety disorder yet the differential relationship sensory sensitivities may show with anxiety symptoms in different domains remains hitherto unexamined.  

Objectives:  The aims of this study were twofold: (1) to investigate the psychometric properties of the SPBQ, including internal consistency, factor structure and convergent validity, and (2) to determine the association between autistic children’s scores on the SPBQ and subtypes of anxiety.

Methods:  

Parents of 67 children with autism and 71 typically developing children, aged between 6 and 17 years were administered the Sensory Processing Behaviour Questionnaire (SPBQ), the Short Sensory Profile (SSP) and the Spence Children’s Anxiety Scale (SCAS), which assesses anxiety symptoms in six domains in keeping with the DSM-IV. Groups were matched on age (p = .25) and IQ (p = .20).

Results:  

As expected, children on the autism spectrum scored significantly higher on the SPBQ than typically developing children of similar age and ability, indicative of greater levels of sensory sensitivities, t(136) = 12.0, p <.001. Internal consistency, factor structure and convergent validity were assessed in the autistic sample only. The 50-item SPBQ showed excellent internal consistency (α = .97) as did the separate frequency (α = .93) and impact (α = .94) scales. Principal components analysis, with varimax rotation, suggested an 8-factor solution. Six of these factors broadly related to daily routines, posture and balance, sensation seeking, noise sensitivity, visual sensitivity and food sensitivities. The two remaining factors were less straightforward to interpret, but one featured difficulties dealing with cluttered environments and the other motor behaviours such as rocking and mouthing objects. The SPBQ scores showed good convergent validity with the most commonly used assessment of sensory symptoms in autism, the SSP (total: r = .79; frequency: r = .78; impact: r = .74). Consistent with previous work, the SPBQ showed a medium-to-strong correlation with children’s anxiety scores on the SCAS (r = .58, p <.001). The SPBQ was most strongly associated with the generalised anxiety subscale (r = .60), and most weakly associated with the social anxiety subscale (r = .17).

Conclusions:  

The SPBQ is a psychometrically valid tool to assess sensory sensitivities in children on the autism spectrum. Its assessment of the impact, as well as the frequency, of sensory sensitivities makes it particularly useful in a clinical context.