Cognitive impairment is undetected in medical inpatients: a study of mortality and recognition amongst healthcare professionals

BACKGROUND: Detecting cognitive impairment in medical inpatients is important due to its association with adverse outcomes. Our aim was to study recognition of cognitive impairment and its association with mortality. METHODS: 200 inpatients aged over 60 years were recruited at the Department of General Internal Medicine at University Hospital MAS in Malmö, Sweden. The MMSE (Mini-Mental State Examination) and the CDT (Clock-Drawing Test) were performed and related to recognition rates by patients, staff physicians, nurses and informants. The impact of abnormal cognitive test results on mortality was studied using a multivariable Cox proportional hazards regression. RESULTS: 55 patients (28%) had no cognitive impairment while 68 patients (34%) had 1 abnormal test result (on MMSE or CDT) and 77 patients (39%) had 2 abnormal test results. Recognition by healthcare professionals was 12% in the group with 1 abnormal test and 44-64% in the group with 2 abnormal test results. In our model, cognitive impairment predicted 12-month mortality with a hazard ratio (95% CI) of 2.86 (1.28-6.39) for the group with 1 abnormal cognitive test and 3.39 (1.54-7.45) for the group with 2 abnormal test results. CONCLUSIONS: Cognitive impairment is frequent in medical inpatients and associated with increased mortality. Recognition rates of cognitive impairment need to be improved in hospitals.