OBJECTIVES 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. METHOD 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. RESULTS 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. CONCLUSIONS 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.

中文翻译：

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符号数字模态测试：多发性硬化症患者的口头和书面版本的希腊规范数据和判别有效性

目标 本研究的目的是为希腊成年人口的书面和口头版本的符号数字模态测试 (SDMT) 生成规范数据。我们还调查了该测试在区分健康成年人与诊断为复发缓解 (RRMS) 和继发性进行性 (SPMS) 多发性硬化症的两组成年人的表现方面的有效性。方法 样本由 609 名年龄在 18 至 65 岁之间的健康男性和女性组成。所有参与者都是母语为单语的希腊成人成人。每个健康参与者都接受了书面 (n = 460) 或口头 (n = 149) 版本的 SDMT。通过比较 35 名完成 SDMT 口头版本的健康参与者与 35 岁和教育匹配的 RRMS 和 SPMS 患者，检验了区分效度。结果 线性回归模型解释了 SDMT 口头和书面版本分数中 36% 到 55% 的差异。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，也占 SDMT 差异的进一步比例。相反，发现性别对书面或口头版本的 SDMT 差异没有显着影响。结果，产生了根据年龄和教育调整的规范。关于测试区分效度，我们发现两个 MS 患者组的得分均显着低于健康组。结论 这是第一项为希腊成年人群的 SDMT 提供全面规范数据的研究，影响了该国未来神经心理学评估的实践。