Associations Between Measures of Disability and Quality of Life at Three Months After Stroke

Background: The modified Rankin Scale (mRS), which measures degree of disability in daily activities, is the most common outcome measure in stroke research. Quality of life (QoL), however, is impacted by factors other than disability. The goal of this study was to assess the correlation between functional dependence and a more patient-centered QoL measure, the European QoL visual analog scale (EQ VAS). Methods: We reviewed prehospital and hospital records from 11 acute care hospitals in Seattle, Washington (USA) from June 2000 to January 2003 for this cohort study. Patients with a final diagnosis of stroke were contacted three to four months after stroke, and mRS and EQ VAS were assessed. Good QoL was defined as EQ VAS ≥65. Results: Of 760 patients with stroke, 346 were available at three to four months. Most (296, 85.5%) had ischemic stroke. Overall, mRS and QoL were negatively correlated (Spearman's ρ -0.53, p < 0.001). Percentage of good QoL decreased as mRS increased from 0 to 5 (88%, 70%, 52%, 50%, 31%, 20%, respectively, p < 0.001). However, 36% (n = 62) of patients with dependent mRS (3-5, n = 174) reported good QoL, and 30% (n = 52) of patients with independent mRS (0-2, n = 172) reported poor QoL. In multivariable analysis, older age, male gender, and absence of dementia, were associated with good QoL despite dependent mRS; atrial fibrillation was associated with poor QoL despite independent mRS. Conclusions: QoL decreases with increasing mRS, but exceptions exist with good QoL despite high mRS. To provide patient-centered care, clinicians and researchers should avoid equating disability with QoL after stroke.