A Chinese version of the Language Screening Test (CLAST) for early-stage stroke patients

There is a severe lack of aphasia screening tools for bedside use in Chinese. A number of aphasia assessment tools have recently been developed abroad, but some of these scales were not suitable for patients with acute stroke. The Language Screening Test (which includes two parallel versions [a/b]) in French has been proven to be an effective and time-saving aphasia screening scale for early-stage stroke patients. Therefore, we worked out a Chinese version of the LAST taking into consideration Chinese language and culture. Two preliminary parallel versions (a/b) were tested on 154 patients with stroke at acute phase and 107 patients with stroke at non-acute phase, with the Western Aphasia Battery serving as a gold standard. The equivalence between the two parallel versions and the reliability/validity of each version were assessed. The median time to complete one preliminary Chinese version (each had some item redundancy) was 98 seconds. Two final parallel versions were established after adjustment/elimination of the redundant items and were found to be equivalent (intra-class correlation coefficient: 0.991). Internal consistency is(Cronbach α for each version [a/b] was 0.956 and 0.965, respectively) good. Internal validity was fine: (a) no floor or ceiling effect/item redundancy; (b) construct validity revealed a 1-dimension structure, just like the French version. The higher educated subjects scored higher than their lower educated counterparts (p<0.01). The external validity: at the optimum cut-off point where the score of version a/b <14 in higher educated group(<13 in lower): the specificity of each version was 0.878/0.902(1/1 in lower) and sensitivity was 0.972/0.944(0.944/0.944 in lower). Inter-rater equivalence (intra-class correlation coefficient) was 1. The Chinese version of the Language Screening Test was proved to be an efficient and time-saving bedside aphasia screening tool for stroke patients at acute phase and can be used by an average medical physician.

目前中文语境下用于床旁使用的失语症筛查工具严重匮乏。近年来国外开发了多款失语症评估工具，但其中部分量表并不适用于急性卒中患者。法语版语言筛查测试（Language Screening Test，以下简称LAST）包含两个平行版本[a/b]，已被证实可有效且省时地用于早期卒中患者的失语症筛查。因此，我们结合中文语言与文化特点，研发了中文版LAST。我们先后在154例急性期卒中患者与107例非急性期卒中患者中对两个初步平行版本（a/b）进行了测试，并以西方失语症成套测验（Western Aphasia Battery, WAB）作为金标准，随后评估了两个平行版本的等效性，以及各版本的信度与效度。两个初步中文版（均存在部分项目冗余）的完成中位时长为98秒。经冗余项目的调整与删减后，我们最终确立了两个平行版本，且二者等效性良好（组内相关系数：0.991）。内部一致性表现优异：两个版本[a/b]的克朗巴赫α系数分别为0.956与0.965。内部效度良好：其一，无地板效应或天花板效应，亦无项目冗余；其二，结构效度显示其单维度结构与原版法语版本一致。受教育程度较高的受试者得分显著高于受教育程度较低者（p<0.01）。外部效度方面：在最优截断值设定下，高教育组版本a/b得分<14分（低教育组<13分）时，版本a与b的特异性分别为0.878与0.902（低教育组分别为1与1），灵敏度分别为0.972与0.944（低教育组均为0.944）。评分者间等效性（组内相关系数）为1。本研究开发的中文版语言筛查测试被证实为一款高效、省时的床旁失语症筛查工具，适用于急性期卒中患者，且可供普通临床医师使用。