Construct validity and reliability of the Test Your Memory Chinese version in older neurology outpatient attendees

Early distinguishing the cognitive impairment from healthy population is crucial to delay the progression of mild cognitive impairment (MCI) and Alzheimer disease (AD). Test Your Memory (TYM) has been proved to be a valid and reliable screening instrument for AD and MCI. This study aimed to develop a culturally appropriate and functional Standard Mandarin Chinese translation of the TYM, and to evaluate its reliability and validity in detecting AD and MCI in Chinese.

182 subjects with AD/MCI and 55 healthy controls were recruited to participate in this study, and everyone undergo the test of Standard Mandarin Chinese version of the TYM (TYM-CN), Mini-mental State Examination (MMSE), Montreal cognitive assessment (MoCA-BJ), and Clinical Dementia Rating (CDR) Scale. Concurrently, all the subjects with AD/MCI received the general physical and neurologic examinations, extensive laboratory tests, and brain computed tomography/magnetic resonance imaging (MRI). Of which, 90 subjects were asked to complete the re-test of TYM-CN at 3 weeks after the initial visit. Intra-class correlation coefficient (ICC) and Cronbach's alpha was used to assess the test-retest reliability and the internal consistency. The validity, sensitivity and specificity were also analyzed. One-way analysis of variance, χ² test, correlation analysis, and receiver operating characteristic curve (ROC) analysis were employed, as needed.

The total scores of TYM-CN was 43.89 ± 3.44, 40.88 ± 4.38, and 29.12 ± 7.44 (p < 0.01) for healthy controls group, MCI group, and AD group, respectively. The ICC for 11 items of TYM-CN ranged from 0.863 (copying) to 0.994 (anterograde), and that of the total scale was 0.993, suggesting an excellent reliability. Furthermore, the significant correlation was also found between TYM-CN and MMSE (r = 0.76), MoCA-BJ (r = 0.74), and CDR scores (r = 0.76), indicating a good validity. A TYM-CN scores ≤ 39.5 had 95% sensitivity and 95% specificity in differentiating AD from healthy controls, and that ≤ 43.5 had 75% sensitivity and 91% specificity in distinguishing MCI from healthy controls, respectively.

The reliability and validity of the TYM-CN are statistically acceptable for the evaluation of cognitive impairment, which may contribute to neuropsychological tests for the diagnosis of AD and MCI from healthy controls in China.