Background: Detecting and treating dementia at an early stage are important. Although the Revised Hasegawa Dementia Scale (HDS-R) is commonly used to detect dementia, it takes about 10 min to complete. In contrast, the 1-min animal test (OMAT) takes only 1 min to complete and may be a helpful screening test for general practitioners in deciding whether to proceed with administering further diagnostic tests such as the HDS-R. We sought to examine the relationship between the OMAT and HDS-R scores, and determine the cut-off OMAT score that balanced the sensitivity and specificity in identifying HDS-R-positive patients.
Methods: A total of 122 consecutive patients with diabetes who visited the outpatient clinic at the Fujiidera Municipal Hospital were enrolled. The patients underwent the OMAT and HDS-R on the same day. Tests were conducted in a single-blinded manner. The relationship between the OMAT and HDS-R scores was examined using Spearman's rank correlation. Receiver operating characteristic curve analysis was performed to identify the optimal cut-off score of OMAT that will determine whether to proceed with further diagnostic tests.
Results: A strong positive correlation between the OMAT and HDS-R scores was observed (r = 0.70). The sensitivity and specificity of OMAT using cut-off scores of 12/13, 13/14, and 14/15 for HDS-R-positive patients were 0.87 and 0.66, 1.00 and 0.51, and 1.00 and 0.40, respectively among all the subjects. Similar results were obtained in a subgroup of subjects aged ≥ 65 years.
Conclusions: A cut-off score of 13/14 on the OMAT balanced the sensitivity closest to 1.00 and allowed for the highest specificity for the HDS-R not only among all the patients, but also among just the patients aged ≥ 65 years. The OMAT may be an optimal screening test to determine whether to proceed with further diagnosis using HDS-R.Trial registration UMIN UMIN000025260. This study is retrospectively registered on December 13th, 2016.
Keywords: 1-min animal test; 1-min mental status examination; Dementia; Revised Hasegawa Dementia Scale; Screening.