Discussion
anxiety/depression, anxiety, motor deficits, neurologic deficits, paresis, nonmotor deficits, hemianopia, Stroke, ataxia, ischemic stroke, aphasia
HEMIANOPIA, PARESIS, STROKE, ISCHEMIC STROKE
We quantified the association between disabling neurologic deficits measured with the NIHSS and the 5 EQ-5D dimension scores and the EQ-5D utility score in patients who had an ischemic stroke. We hypothesized that language problems and other nonmotor deficits are not captured as well as motor deficits by this system. This study showed that the explained variance of neurologic deficits was lower on the dimensions pain/discomfort and anxiety/depression than on the other EQ-5D dimension scores and the utility score. Motor deficits caused by limb paresis explained more of the variance on the EQ-5D dimension scores and the utility score than other nonmotor deficits such as hemianopia, aphasia, and neglect.Our results are in line with previous research showing that the EQ-5D dimensions mobility, self-care, and usual activities were more strongly correlated with the modified Rankin scale and Barthel index than the EQ-5D dimensions pain/discomfort and anxiety/depression in patients with ischemic stroke.We used the NIHSS to quantify the association between neurologic deficits and the EQ-5D dimension scores and the utility score. Although the NIHSS and the EQ-5D are instruments with different purposes, one can imagine that disabling neurologic deficits should be reflected in the EQ-5D to a certain extent. We expected that the dimensions pain/discomfort and anxiety/depression would be influenced by aphasia because we assumed aphasia may limit participation, might cause anxiety, and might cause cognitive and emotional discomfort.Quality of life can be measured with generic measures or disease-specific measures, such as the Stroke-Specific Quality of Life, Stroke Impact Scale or STATIS-Stroke for ischemic stroke.This study has some limitations. The study population consisted mainly of patients with anterior circulation ischemic stroke. Therefore, only a few patients had ataxia, and we cannot draw any conclusions about the association between ataxia and the EQ-5D. We expect that ataxia does substantially influence the EQ-5D, especially on the dimensions mobility, self-care, and usual-activities, but this should be confirmed in future research. In our study, patients with missing values on the NIHSS and/or EQ-5D at 90 days had worse outcomes compared with patients without missing values. It is worrisome that missing values on the NIHSS and/or EQ-5D might be associated with outcomes. However, because we used multiple imputation based on relevant covariates including outcomes, which provides less biased estimates compared with excluding those patients, we expect that those missing values did not influence our results.To conclude, the 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.