Background and ObjectivesThe EuroQol Group 5-Dimension Self-Reported Questionnaire (EQ-5D) is a well-established instrument to assess quality of life and generates generic utility values for health states reported by patients, derived from assessments by the general public. We hypothesized that language problems and other nonmotor deficits are not captured as well as motor deficits by this system. We aimed to quantify the association between disabling neurologic deficits and the EQ-5D dimension scores and the utility score in patients with ischemic stroke.MethodsWe used data of the Interventional Management of Stroke III trial. Missing data were imputed by multiple imputation. The association between neurologic deficits (individual NIH Stroke Scale [NIHSS] item scores) and the EQ-5D-3L (5 three-level dimension scores and utility score) at 90 days was assessed with ordinal logistic regression and Tobit regression, respectively. The explained variance of each model was estimated with Nagelkerke pseudo-R²or R².ResultsIn total, 525 surviving patients were included. Complete data on both the NIHSS and EQ-5D were available for 481/525 (91.6%) patients. At 90 days, 161/491 (32.8%) patients had aphasia and 226/491 (46.0%) patients had paresis of at least 1 limb. Limb paresis, facial palsy, sensory loss, and dysarthria explained most of the variance in all EQ-5D dimension scores and the utility score. In the utility score, 8.9% of the variance was explained by neglect, 10.0% by aphasia, 10.8% by hemianopia, and 17.5%–24.1% by limb paresis.DiscussionThe impact of neurologic deficits on the EQ-5D in patients with ischemic stroke is mostly due to limb paresis, while the EQ-5D is less sensitive to other nonmotor deficits such as hemianopia, aphasia, and neglect. This may lead to overestimation of quality of life and, consequently, underestimation of the (cost-)effectiveness of treatments and interventions.Trial Registration InformationClinicalTrials.gov. Unique identifier:NCT00359424.