The 8-item Informant Interview to Differentiate Aging and Dementia (AD8) was developed as a screening tool for dementia with a cutoff of 2 suggested by the initial study. However, various studies found different cutoff values, and many suggested a cutoff of 2 might result in a high false positive rate. A higher false positive rate in Taiwan was repeatedly shown when AD8 was self-administered in local government screening programs. We have developed a modified version of AD8 (m-AD8) with the purpose of enhancing its specificity. This study aimed to compare the performance of AD8 and m-AD8.

The m-AD8 consists of all items adapted from the original AD8. Modifications included: (1) limiting the evaluated period to the past year instead of the past several years, (2) reselecting examples to reflect the socio-cultural context in Taiwan, and (3) rearranging the order of questions according to their complexity. We recruited 118 participant-informant dyads from a university teaching hospital. For each informant, the AD8 was administered first and then the Clinical Dementia Rating (CDR) to minimize contamination effect. The m-AD8 was administered 7 days later. Two geriatric psychiatrists made the final consensus DSM-5 diagnosis for each subject after considering all clinical information, including history, Mini-Mental State Examination (MMSE), CDR, and, if available, other past neuropsychological tests and neuroimaging.

There were 59 subjects with normal cognition, 28 with mild neurocognitive disorder, and 31 with dementia (major neurocognitive disorder). When comparing dementia vs. non-dementia, the optimal cutoff value was 4 for both versions according to the Youden index. The AUC, sensitivity, and specificity were 0.893, 0.774, 0.862 for AD8, and 0.883, 0.741, 0.954 for m-AD8, respectively. The m-AD8 showed improved specificity, which was also true when the cutoff value was set as 2 or 3.

The optimal cutoff value for both versions was 4. The modification may change the performance of AD8 with improved specificity. These findings suggest that, depending on different situations, AD8 with a cutoff value higher than 2 may perform better in dementia screening.