Cognitive assessment in elderly patients admitted to hospital: the relationship between the Abbreviated Mental Test and the Mini-Mental State Examination.

Abstract

To determine the relationship between Abbreviated Mental Test (AMT) and the Mini-Mental State Examination (MMSE) in elderly patients admitted to hospital. Prospective study of 364 consecutive admissions to an elderly medicine unit. Eighty-eight (24.2%) patients were excluded. The AMT and MMSE were administered to the remaining 276 patients and the relationship between the two tests evaluated statistically. Inner city teaching hospital. Two hundred and seventy-six patients admitted to the elderly medicine unit during October and November 1997. Predictive efficiency of the AMT for cognitive state by MMSE (the percentage of patients whose cognitive state by the MMSE was correctly categorized by the AMT). Association and predictive relationship between individual AMT and MMSE scores. There was a significant relationship between cognitive state as determined by the AMT and MMSE: chi2 = 101.3, df = 1, p <0.001. The predictive efficiency of the AMT was 79.0% (218/276). A strong association was found between the AMT and MMSE (Somers' d statistic 0.75: p <0.001). Simple linear regression allowed prediction of the MMSE score from the AMT score as follows: MMSE score = 7.06 + (1.94 x AMT score); p <0.001. In patients admitted to the elderly medicine unit, the AMT gave predictive information about cognitive status as determined by the MMSE, and also a prediction of likely MMSE score.