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UBC Theses and Dissertations

An evaluation of a teacher reported measure for the early identification of selective mutism Martinez, Yvonne Julia


Selective mutism (SM) is a childhood disorder characterized by failure to speak in social situations despite there being an expectation to speak and the capacity to do so. The prevalence of SM among children is estimated to be between approximately 0.5 to 1% (Sharp, Sherman, & Gross, 2007). Children with SM exhibit more symptoms at school than at home, yet current identification and diagnosis of SM relies exclusively on parent reports (McInnes & Manassis, 2005; Schniering, Hudson, & Rapee, 2000). There is often a 3 to 6 year delay in SM referrals because parents do not recognize symptoms until children begin school. SM appears to interfere with achievement and social-emotional development in children (Sharp et al., 2007). The first phase of the study involved the development and validation of the Teacher Telephone Interview: Selective Mutism & Anxiety in the School Setting (TTI-SM-DSM-IV; Tannock, Fung, & Manassis, 2003), to teachers of a clinical sample of 29 children (Kindergarten to Grade 5) referred to three large urban hospitals for SM across Canada. The second phase was a follow-up validation study that involved the revision of the TTI-SM-DSM-IV into a paper-pencil measure, the TTI-SM-R. The revised TTI-SM-R was administered to a sample of 30 (Kindergarten to Grade 4) teachers of children in the community with SM and normal controls in western Canada. The third phase combined the clinical and community samples for a total sample of 59 participants. The results indicated that the Mutism subscale of the TTI-SM-DSM-IV and TTI-SM-R demonstrated evidence of reliability and validity (construct, face, predictive, concurrent, convergent, discriminant) for assessing SM. Additionally, the results showed that students with SM were found to have more symptoms of social and school anxiety and greater difficulty with daily social participation compared to children without SM. The analyses also revealed a high concordance rate between parent and teacher ratings of children with SM. The development and validation of a teacher reported measure for SM may help reduce the lag time between symptom onset and treatment referral for students with SM. The findings may contribute to a better understanding of anxiety symptomatology in students with SM, and the impact of mutism on social behaviours.

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