The Mini-Cog, Clock Drawing Test, and the Mini-Mental State Examination in a German memory clinic: specificity of separation dementia from depression.
BACKGROUND
The aim of this study was to assess the specificities of the Mini-Cog, the Clock Drawing Test (CDT), and the Mini-Mental State Examination (MMSE) against depression and healthy controls in a German Memory Clinic. Furthermore, we analyzed the specificities of all three screening instruments in dependence of actual depression severity.


METHODS
Data from 142 depressed elderly, 438 dementia patients, and 64 healthy controls were retrospectively analyzed. The CDT and an extraction of the three-item recall of the MMSE were used to constitute the Mini-Cog algorithm. Depression severity was rated by either the Beck Depression Inventory (BDI) or the Geriatric Depression Scale (GDS) depending on the age of the patients.


RESULTS
The Mini-Cog achieved a specificity of 79.6% against depressed elderly and 100.0% against healthy subjects (p < 0.001). Similarly, the specificities of the CDT (83.8%) and MMSE (92.3% at a cut-off ≤24 and 90.8% at ≤25, respectively) against healthy subjects were significantly higher than the specificities against depressed patients (each p < 0.05). Concerning the depressed patients, the MMSE demonstrated significant higher specificity than the Mini-Cog and the CDT, but also showed the lowest sensitivity for the detection of dementia. Surprisingly, the depression severity had no effect on the specificity of the Mini-Cog and the CDT, only the MMSE was susceptible for the depression severity.


CONCLUSIONS
Although the MMSE showed higher specificities, the weighting between the sensitivities and specificities in all tests prove again the Mini-Cog as a short, valid, and sensitive screening tool.
Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany. monika.milian@med.uni-tuebingen.de
Monika
M
Milian
Anna-Maria
AM
Leiherr
Guido
G
Straten
Stephan
S
Müller
Thomas
T
Leyhe
Gerhard W
GW
Eschweiler
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003704:Dementia / Q000175:diagnosis* / Q000523:psychology; D003863:Depression / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index