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.