Abstract 2435: Validation of the 12-Item Stroke-Specific Quality of Life Scale in a Bi-ethnic Stroke Population

Abstract

Background and Purpose: The 12-item Stroke-Specific Quality of Life Scale (SSQOL), a shortened version of the original SSQOL, was recently developed in a mixed cerebrovascular disorders population from the Netherlands. Lacking, however, are validation studies of the shortened version specifically in ischemic stroke patients alone and in those from other race-ethnic backgrounds. We aimed to assess the validity of this scale in a bi-ethnic ischemic stroke population. Methods: From an on-going population-based study, the Brain Attack Surveillance in Corpus Christi (BASIC) Project, validated ischemic stroke patients who completed the 49-item SSQOL at 90 days post-stroke were identified. Cronbach’s alpha was used to assess internal consistency of the 49- and 12-item scales. An intraclass correlation coefficient (ICC) and linear regression model were used to assess agreement between the two scales and the variance of the 49-item SSQOL explained by the 12-item SSQOL subscale. The Bland-Altman “differences against the mean” plot was used to assess for bias in the 12-item scale across the range of scores. Results: Of the 46 ischemic stroke patients, the mean age was 66.3 years (SD, 11.4). Fifty-four percent were female and 52% were Mexican American. The mean score of the 49-tem scale was 3.35 (SD, 0.85) compared with 3.34 (SD, 0.96) from the 12-item scale. Internal consistency was very high for both the 49-item scale (α = 0.96) and the 12-item scale (α = 0.88). More than 96% of the variance in the 49-item scale was explained by the 12-item scale (ICC, 0.98; R 2 , 0.97). The Bland Altman plot revealed that the 12-item scale scores were slightly higher than 49-item scores at high mean scores and slightly lower at low mean scores ( Figure ). Conclusions: This study in ischemic stroke patients from diverse race-ethnic backgrounds found that the more efficient 12-item SSQOL is a valid alternative to the full scale for the assessment of health-related quality of life. Figure. Bland-Altman plot of the differences between the 49-item Stroke Specific Quality of Life (SSQOL) scale and the 12-item SSQOL. Each circle represents an individual patient. The x-axis is computed as the average of the 49-item and 12-item scores, and the y-axis is the difference between the 49-item and 12-item scores. The dashed horizontal line represents the mean difference and the shaded region represents the mean difference ± 2 standard deviations.