Search

Aim: The Clock Drawing Test (CDT) is a popular screening test to detect of dementia. The aim of the present research was to determine the role of the test in diagnosing early stages of Alzheimer‘s disease (AD). Patients and methods: The Mini-Mental State Examination (MMSE) and the CDT with three times 11:10, 23:20 and 5:40 were examined in 77 cognitively normal seniors (NOS) and in 77 patients diagnosed with early AD according to NIA-AA criteria. All CDTs were scored according to the instructions in the Addenbrooke´s and Montreal cognitive tests (ACE, MoCA), Shulman´s system and by our newly developed BaJa system with fi ve dichotomous questions and 0-5 scale. Results: MMSE and CDT scores with any of the three times (11:10, 23:20, 5:40) assessed by any system were signifi cantly lower for the early AD patients than for the NOS group (p < 0.01). The 23:20 was signifi cantly more diffi cult than 11:10 for all participants (p = 0.003). A comparison of patients and NOS for three times of the CDT showed a cut-off score for BaJa ≤ 4 points, sensitivity 54-65%, specifi city of 59-75% and the area under the receiver operating curve (AUC) around 0.7. The MMSE cut-off score ≤ 27 points was associated with higher sensitivity of 86%, specifi city 96% and AUC 0.96. There were no diff erences between the four CDT scoring systems with respect to AUCs. Conclusion: Although the CDT with 23:20 is more diffi cult than the other times, the CDT in general is not useful for early detection of AD due to its low sensitivity and specifi city, regardless of what time or scoring system is used. [ABSTRACT FROM AUTHOR]