Development and Validation of a New Stroke Outcome Scale (Stroke Impact Assessment Questionnaire).

Background: Stroke affects the quality of life through its devastating effects on physical, psychological, social, and economic domains. Patient-reported outcome measures help to capture the patient's perspective to changes in the quality of life. The available stroke-specific outcome measures of stroke do not comprehensively measure all the domains. Objective: We describe the development and validation of the Stroke Impact Assessment Questionnaire (SIAQ) an interviewer-administered new instrument developed using patient-centered approaches to assess the long-term problems of stroke survivors. Materials and Methodology: We used a sequential exploratory mixed methods approach (QUAL → QUAN) to develop the SIAQ. The design involves an initial qualitative phase aimed at generating the item pool and a subsequent second phase aimed at testing of items using quantitative techniques (Psychometric evaluation). Result: SIAQ, a thirty-item tool, under the eight domains (sensory, motor, social, economic, emotional, behavioral, cognitive, and communication) emerged from Principal Component Analysis. The factor loadings ranged from 0.421 to 0.880. The intraclass coefficient in test-retest reliability r is 0.958 (95% CI 0.9249-0.9799) and in interobserver reliability is 0.9473 (95% CI 0.9125 - 0.9733). The internal consistency Cronbach's alpha for the final 30 item tool was 0.88. Conclusion: SIAQ is a culturally appropriate psychometrically robust questionnaire assessing the long-term outcome of stroke. However, SIAQ is applicable only in stroke survivors for up to 65 years.