[Short evaluation of cognitive state in advanced stages of dementia: preliminary results of the Spanish validation of the Severe Mini-Mental State Examination].

INTRODUCTION: The cognitive assessment of patients with advanced dementia needs proper screening instruments that allow obtain information about the cognitive state and resources that these individuals still have. The present work conducts a Spanish validation study of the Severe Mini Mental State Examination (SMMSE).
MATERIAL AND METHODS: Forty-seven patients with advanced dementia (Mini-Cognitive Examination [MEC]<11) were evaluated with the Reisberg's Global Deterioration Scale, MEC, SMMSE and Severe Cognitive Impairment Profile scales.
RESULTS: All test items were discriminative. The test showed high internal (α=0.88), test-retest (0.64 to 1.00, P<.01) and between observers reliabilities (0.69-1.00, p<0.01), both for scores total and for each item separately. Construct validity was tested through correlations between the instrument and MEC scores (r=0.59, P<0.01). Further information on the construct validity was obtained by dividing the sample into groups that scored above or below 5 points in the MEC and recalculating their correlations with SMMSE. The correlation between the scores in the SMMSE and MEC was significant in the MEC 0-5 group (r=0.55, P<.05), but not in the MEC>5 group. Additionally, differences in scores were found in the SMMSE, but not in the MEC, between the three GDS groups (5, 6 and 7) (H=11.1, P<.05).
CONCLUSIONS: The SMMSE is an instrument for the assessment of advanced cognitive impairment which prevents the floor effect through an extension of lower measurement range relative to that of the MEC. From our results, this rapid screening tool and easy to administer, can be considered valid and reliable.