Most neuropsychological batteries, especially those most often used, are unsuitable for the assessment of patients with severe dementia. The Severe Impairment Battery (SIB) was developed for the evaluation of preserved cognitive functions in these patients. The aim of this study was to formulate a Greek version of the SIB and to conduct a first assessment of its use of patients with mild, moderate, or severe Alzheimer's disease (AD), compared to the Mini-Mental State Examination (MMSE).

A convenience sample of 42 dementia patients according to DSM-IV-TR criteria and 23 healthy participants was selected. Patients were assessed twice using a Greek translation of the SIB and the Greek version of MMSE. Patients were divided into three severity groups based on grouped by Clinical Dementia Rating (CDR) score and the SIB and MMSE scores were compared.

The validity of the SIB was confirmed by evaluating the correlation coefficients between the SIB and Greek-MMSE, grouped by CDR, which were found to be significant. Cronbach's α for the total SIB score and each subscale score showed high significance, and the item-total correlation for each subscale was also acceptable. The test-retest correlation for the total SIB score and subscale scores were significant. The total SIB score and subscale scores were examined according to CDR.

The Greek SIB is reliable and valid in differentiating patients with moderate or severe dementia, whereas MMSE loses sensitivity due to a floor and ceiling effect.