Ethnicity and other determinants of quality of functional outcome in acute ischemic stroke: the ENCHANTED trial

Background and Purpose- Patient-centered outcomes are important. We aimed to determine predictors of health-related quality of life (HRQoL) and develop utility-weighted modified Rankin Scale (mRS) scores in thrombolyzed acute ischemic stroke patients from both arms of ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study). Methods- ENCHANTED was an international quasi-factorial clinical trial of different doses of intravenous alteplase and intensities of blood pressure control in acute ischemic stroke patients, with outcomes on the 5-Dimensional European Quality of Life Scale and mRS assessed at 90 days post-randomization. Logistic regression models were used to identify baseline predictors of poor HRQoL (≤mean 5-Dimensional European Quality of Life Scale utility scores). Ordinary least squares regression derived utility-weighted mRS scores. Results- In 4016 acute ischemic stroke patients with complete 5-Dimensional European Quality of Life Scale and mRS data, independent predictors of poor HRQoL were older age (odds ratio, 1.19 [95% CI, 1.12-1.27], per 10-year increase), non-Asian ethnicity (1.91 [1.61-2.27]), greater stroke severity on the National Institutes of Health Stroke Scale (1.11 [1.09-1.12]), diabetes mellitus (1.41 [1.18-1.69]), premorbid disability (mRS score 1 versus 0; 1.62 [1.33-1.97]), large vessel atheromatous pathogenesis (1.32 [1.12-1.54]), and proxy respondent (2.35 [2.01-2.74]). Sensitivity analyses indicate the ethnicity influence on HRQoL was driven by the high proportion of Chinese (62.9% of Asian) participants with better HRQoL compared with non-Chinese or other Asian groups. Derived utility values across mRS scores 0 to 5 were 0.977, 0.885, 0.748, 0.576, 0.194, and -0.174, respectively. Correlations between mRS and 5-Dimensional European Quality of Life Scale scores were stronger in Asians. Conclusions- HRQoL is worse after thrombolyzed acute ischemic stroke in the elderly, non-Asians, with greater initial severity, diabetes mellitus, premorbid disability, due to large vessel atheroma, and proxy assessment. The broader significance of better HRQoL in Asians is tempered by Chinese participants dominating analyses. From utility-weighted mRS scores indicating the greatest steps in mRS scores are between 5 and 3, treatments to avoid major disability provide the greatest benefits for patients. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT01422616.