Abstract 42: Validation of an Ordinal, 6-Item Functional Outcome Scale for Speech and Language Disability in Stroke: The Austin Speech Labs Communication Disability Scale

Abstract

Introduction: Assessment of stroke outcomes specific to speech and language typically depends on lengthy batteries yielding a derived score that has little functional meaning to patients. Our aim was to develop a simple, highly reliable, ordinal outcome scale specific to language and communication disability. Methods: Modeled after the Rankin Scale, the Communication Disability Scale is a 6-item ordinal scale to assess degree of disability specifically related to communication deficits. Inter-rater reliability and criterion validity were tested on a cohort of 79 stroke patients with communication /speech deficits in an outpatient intensive speech therapy setting. Speech therapists independently assessed the patients. 0 - No speech or language deficits. 1 - Minor language deficits, without communication limitations. 2 - Language deficits causing limitations on communication, but not on ADLs. 3 - Limitations in ADLs caused or exacerbated by communication deficits*. 4 - Requires listener assistance and inference for most communications of basic needs*. 5 - No effective communication*. *Needs caregiver assistance Results: Inter-rater reliability of the Communication Disability Scale scores (CDS) for all subjects (n=79) yielded an intra-class correlation of 0.823. The kappa statistic for agreement was 0.792. Comparison to a standardized language assessment, the Western Aphasia Battery Aphasia Quotient (WAB-AQ) (n=71) showed a strong correlation on Spearman rank rho = -0.815. When CDS and WAB-AQ were dichotomized as good (0-2, does not require caregiver assistance for communication needs) v bad, kappa was 0.6223 (p < 0.001). Conclusion: The Austin Speech Labs Communication Disability Scale has high inter-rater reliability and is highly correlated with a standard Aphasia Battery. The items link language deficits to limitations in activities of daily living (ADLs) attributable to communication deficits. This new scale may be valuable in assessing the effects of speech therapies in clinical trials and the need for caregiver assistance in practice.