Neuropsychology Section, Departments of Neurology and Psychiatry, University Hospital of Patras and University of Patras Medical School, Patras, Greece.
B'Department of Neurology and the MS Center, AHEPA University Hospital, Central Macedonia, Thessaloniki, Greece.
Arch Clin Neuropsychol. 2021 Jan 15;36(1):117-125. doi: 10.1093/arclin/acaa028.
The purpose of this study was to generate normative data on the Symbol Digits Modalities Test (SDMT) for the written and oral versions in the Greek adult population. We also investigated the test's validity in discriminating the performance of healthy adults from two groups of adults diagnosed with relapsing remitting (RRMS) and secondary progressive (SPMS) multiple sclerosis.
The sample consisted of 609 healthy men and women between the ages of 18 and 65. All participants were monolingual native Greek adult speakers. Each healthy participant was administered either the written (n = 460) or oral (n = 149) versions of the SDMT. Discriminant validity was examined by comparing 35 healthy participants who had completed the oral version of the SDMT to 35 age - and education-matched RRMS and SPMS patients.
Linear regression models explained between 36% and 55% of the variance in the SDMT oral and written version scores. Age was the strongest predictor of difference in SDMT written and oral version performance, followed by education that also accounted for a further proportion of the SDMT variance. On the contrary, gender was found not to contribute significantly to the variance in the SDMT for either the written or the oral versions. As a result, age- and education-adjusted norms were generated. Regarding the tests discriminative validity, we found that both MS patient groups scored significantly lower than the healthy group.
This is the first study to provide comprehensive normative data for the SDMT in the adult population in Greece, impacting the future practice of neuropsychological assessment in this country.
本研究旨在为希腊成年人群体的书面和口头符号数字模态测验（SDMT）生成常模数据。我们还研究了该测试在区分健康成年人与被诊断为复发缓解型（RRMS）和继发进展型（SPMS）多发性硬化症的两组成年人的表现方面的有效性。
样本由 609 名年龄在 18 至 65 岁之间的健康男女组成。所有参与者均为单语母语为希腊语的成年发言者。每位健康参与者均接受了书面（n=460）或口头（n=149）版本的 SDMT 测试。通过比较完成 SDMT 口头版本的 35 名健康参与者和 35 名年龄和教育程度相匹配的 RRMS 和 SPMS 患者，评估了判别有效性。
线性回归模型解释了 SDMT 口头和书面版本得分的 36%至 55%的方差。年龄是 SDMT 书面和口头版本表现差异的最强预测因素，其次是教育程度，它也解释了 SDMT 方差的进一步比例。相反，研究发现性别对 SDMT 的书面或口头版本的方差没有显著贡献。因此，生成了年龄和教育程度调整的常模。关于测试的判别有效性，我们发现两组 MS 患者的得分均明显低于健康组。
这是第一项在希腊成年人群体中提供 SDMT 全面常模数据的研究，对该国未来的神经心理评估实践产生了影响。
