Research Institute MOVE, Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, The Netherlands.
J Neurol Sci. 2010 Jul 15;294(1-2):57-61. doi: 10.1016/j.jns.2010.04.004. Epub 2010 May 2.
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.
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.
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.
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.
早期预测未来的功能能力对于脑卒中管理至关重要。本研究旨在探讨 13 项国立卫生研究院卒中量表（NIHSS）在卒中后 72 小时内测量的预测价值，以评估卒中后 6 个月的日常生活活动（ADL）结局。目的是检验 NIHSS 评估时间在卒中后前几天是否影响卒中后 6 个月 ADL 结局预测的准确性。
188 例首次缺血性半球卒中患者在卒中后 2、5 和 9 天内，使用 13 项 NIHSS 量表测量基线特征，包括神经功能缺损。使用 Barthel 指数（BI）在卒中后 6 个月评估 ADL 依赖性结局。采用受试者工作特征（ROC）曲线下面积（AUC）确定 NIHSS 在第 2、5 和 9 天对 BI 结局的区分能力。此外，计算不同 NIHSS 评估时间点的最佳截断比值比（OR）、敏感性、特异性、阳性预测值（PPV）和阴性预测值（NPV）。
188 例患者中，159 例在卒中后平均 2.2（1.3）、5.4（1.4）和 9.0（1.8）天进行评估。BI 在 6 个月与 NIHSS 在第 2 天（r(s)=0.549，p<0.001）、第 5 天（r(s)=0.592，p<0.001）和第 9 天（r(s)=0.567，p<0.001）的评分之间存在显著的 Spearman 秩相关系数。AUC 范围从第 2 天的 0.789（95%CI，0.715-0.864）到第 5 天的 0.804（95%CI，0.733-0.874）和第 9 天的 0.808（95%CI，0.739-0.877）。OR 范围从第 2 天的 0.143（95%CI，0.069-0.295）到第 5 天的最大值 0.148（95%CI，0.073-0.301）。NPV 从第 2 天的 0.610（95%CI，0.536-0.672）逐渐增加到第 9 天的 0.679（95%CI，0.578-0.765），而 PPV 从第 2 天的 0.810（95%CI，0.747-0.875）下降到第 9 天的 0.767（95%CI，0.712-0.814）。预测的总体准确性从第 2 天的 71.7%增加到第 9 天的 73.6%。
在卒中后 9 天内测量时，13 项 NIHSS 与卒中后 6 个月的 BI 结局高度相关。评估时间超过 2 天后，不会显著影响 ADL 依赖性的 6 个月预测准确性。因此，NIHSS 可在卒中后急性医院卒中单元早期用于康复管理，因为预测的准确性保持在 72%左右，而与评估时间无关。
