Detailed analysis of the Japanese version of the Rapid Dementia Screening Test using Arabic-hiragana conversion

AIM: The number-transcoding task on the Japanese version of the Rapid Dementia Screening Test (RDST-J) requires conversion between Arabic and Chinese numerals (209 to , 4054 to , to 681, to 2027). In this task, questions and answers are written for Chinese-Arabic conversion. We reported that the RDST-J could distinguish subjects with Alzheimer's disease with a Clinical Dementia Rating Scale score of 0.5 from controls. In this study, we investigated the impact of changing the task to a hiragana-Arabic conversion. METHODS: Participants consisted of 45 patients with a Clinical Dementia Rating Scale score of 0.5 and 52 normal controls. RESULTS: The sensitivity and specificity of total scores ≥9 on the two RDST-J versions for discriminating subjects with a Clinical Dementia Rating Scale score of 0.5 from controls were 73.1% and 75.5%, respectively, on the original version, and 71.8% and 73.0%, respectively, on the revised version. CONCLUSIONS: The sensitivity and specificity of the revised version of the RDST-J was equivalent to those of the original version.