Predictive value of the NIHSS for ADL outcome after ischemic hemispheric stroke: Does timing of early assessment matter?

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• 作者：Gert Kwakkel ; Janne M. Veerbeek ; Erwin E.H. van Wegen ; Rinske Nijl ; Barbara C. Harmeling-van der Wel ; Diederik W.J. Dippel ; the EPOS investigators
• 关键词：Ischemic stroke ; Prognosis ; ADL ; NIHSS
• 刊名：Journal of the Neurological Sciences
• 出版年：2010
• 出版时间：15 July 2010
• 年：2010
• 卷：294
• 期：1-2
• 页码：57-61
• 全文大小：236 K

文摘

Background and purpose

Early prediction of future functional abilities is important for stroke management. The objective of the present study was to investigate the predictive value of the 13-item National Institutes of Health Stroke Scale (NIHSS), measured within 72 h after stroke, for the outcome in terms of activities of daily living (ADL) 6 months post stroke. The second aim was to examine if the timing of NIHSS assessment during the first days post stroke affects the accuracy of predicting ADL outcome 6 months post stroke.

Methods

Baseline characteristics including neurological deficits were measured in 188 stroke patients, using the 13-item NIHSS, within 72 h and at 5 and 9 days after a first-ever ischemic hemispheric stroke. Outcome in terms of ADL dependency was measured with the Barthel Index (BI) at 6 months post stroke. The area under the curve (AUC) from the receiver operating characteristic (ROC) was used to determine the discriminative properties of the NIHSS at days 2, 5 and 9 for outcome of the BI. In addition, at optimal cut-off odds ratio (OR), sensitivity, specificity, positive (PPV) and negative predicted values (NPV) for the different moments of NIHSS assessment post stroke were calculated.

Results

One hundred and fifty-nine of the 188 patients were assessed at a mean of 2.2 (1.3), 5.4 (1.4) and 9.0 (1.8) days after stroke. Significant Spearman rank correlation coefficients were found between BI at 6 months and NIHSS scores on days 2 (r_s = 0.549, p < 0.001), 5 (r_s = 0.592, p < 0.001) and 9 (r_s = 0.567, p < 0.001). The AUC ranged from 0.789 (95 % CI, 0.715–0.864) for measurements on day 2 to 0.804 (95 % CI, 0.733–0.874) and 0.808 (95 % CI, 0.739–0.877) for days 5 and 9, respectively. Odds ratio's ranged from 0.143 (95 % CI, 0.069–0.295) for assessment on day 2 to a maximum of 0.148 (95 % CI, 0.073–0.301) for day 5. The NPV gradually increased from 0.610 (95 % CI, 0.536–0.672) for assessment on day 2 to 0.679 (95 % CI, 0.578–0.765) for day 9, whereas PPV declined from 0.810 (95 % CI, 0.747–0.875) for assessment on day 2 to 0.767 (95 % CI, 0.712–0.814) for day 9. The overall accuracy of predictions increased from 71.7 % for assessment on day 2 to 73.6 % for day 9.

Conclusions

When measured within 9 days, the 13-item NIHSS is highly associated with final outcome in terms of BI at 6 months post stroke. The moment of assessment beyond 2 days post stroke does not significantly affect the accuracy of prediction of ADL dependency at 6 months. The NIHSS can therefore be used at acute hospital stroke units for early rehabilitation management during the first 9 days post stroke, as the accuracy of prediction remained about 72 % , irrespective of the moment of assessment.