Stroke and Aphasia Quality of Life Scale-39 (SAQOL-39): evaluation of acceptability, reliability, and validity

Abstract

Background and purpose: Health-related quality of life (HRQL) is a key outcome in stroke clinical trials. Stroke-specific HRQL scales (eg, SS-QOL, SIS) have generally been developed with samples of stroke survivors that exclude people with aphasia. We adapted the SS-QOL for use with people with aphasia to produce the Stroke and Aphasia Quality of Life Scale (SAQOL). We report results from the psychometric evaluation of the initial 53-item SAQOL and the item-reduced SAQOL-39.

Methods: We studied 95 people with long-term aphasia to evaluate the acceptability, reliability, and validity of the SAQOL and SAQOL-39 using standard psychometric methods.

Results: A total of 83 of 95 (87%) were able to complete the SAQOL by self-report; their results are reported here. Results supported the reliability and validity of the overall score on the 53-item SAQOL, but there was little support for hypothesized subdomains. Using factor analysis, we derived a shorter version (SAQOL-39) that identified 4 subdomains (physical, psychosocial, communication, and energy). The SAQOL-39 demonstrated good acceptability, internal consistency (Cronbach's alpha=0.74 to 0.94), test-retest reliability (intraclass correlation coefficient=0.89 to 0.98), and construct validity (corrected domain-total correlations, r=0.38 to 0.58; convergent, r=0.55 to 0.67; discriminant, r=0.02 to 0.27 validity).

Conclusions: The SAQOL-39 is an acceptable, reliable, and valid measure of HRQL in people with long-term aphasia. Further testing is needed to evaluate the responsiveness of the SAQOL-39 and to investigate its usefulness in evaluative research and routine clinical practice.