A Scale to Measure Impairment in Severe Dementia and Similar Conditions.

The authors describe an 11-item, 22-point scale that measures cognitive capacity in severely cognitively impaired individuals. The Severe Impairment Rating Scale (SIRS) has acceptable interrater reliability (r = 0.992; P < 0.001), test-retest reliability (r = 0.97; P < 0.0001), and internal consistency (Chronbach's alpha = 0.76). Validity is supported by correlations with the Glasgow Coma Scale (r = 0.866; P < 0.001) and Mini-Mental State Examination (r = 0.770; P < 0.001).