[The coin test].
BACKGROUND
Normal persons, whatever their level of education, have innate basic mathematical ability, but this is very sensitive to deterioration of cognitive function. The tests currently available do not permit evaluation of this ability in patients who cannot read or have little education. The coin test (CT) was designed with this in mind.


OBJECTIVE
To assess the application and use of CT for diagnosis of dementia in a poorly educated population.


METHODS
We studied 211 persons, 114 with dementia (criteria DSM-IV) and 97 without dementia (50 normal, 20 with deteriorated memory and 27 with cognitive deterioration), and 26 who were unable to read. CT was used in an independent, blind manner with regard to the diagnosis. We calculated the sensitivity (S), specificity (SP), positive (PPV) and negative (NPV) predictive values, correct classifications (CC) and positive likelihood ratio (RV+) for all the results obtained.


RESULTS
The groups did not differ with regard to age, sex or studies. The cut off point < or = 7, S = 0.89, SP = 0.92, PPV = 0.92, NPV = 0.88 and CC = 0.90.


CONCLUSIONS
The CT can be adapted to any society, is economical, ecological, valid, quick useful and well accepted. It is very sensitive and specific for the diagnosis of dementia.
Carnero-Pardo
C
C
Servicio de Neurología, Hospital Torrecárdenas, Almería, España. ccarnerop@meditex.es
Lendínez-González
A
A
Navarro-González
E
E
D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis*; D003704:Dementia / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales