ASSESSMENT OF MENTAL-ABILITY IN ELDERLY ANTICOAGULATED PATIENTS - ITSREDUCTION IS ASSOCIATED WITH A LESS SATISFACTORY QUALITY OF TREATMENT

Mental capacity was assessed in 311 apparently self-sufficient patient s (greater than or equal to 60 years of age, 170 men) under stabilised oral anticoagulant treatment (OAT) by administering the Hodkinson's A bbreviated Mental Test (AMT). The international normalized ratios (INR ) recorded during the 3 months before and the 3 after the date of test administration were examined by the INR-Day software program. The per centage of time spent within, below or above the intended therapeutic range was calculated in patients who scored abnormally at AMT, and com pared with matched controls with normal AMT results. Forty patients [1 2.9%; 28 women (19.8%) and 12 men (7.1%), P < 0.0011] had abnormal AMT results; the rate seemed to increase with age. Most of these patients (35, 75%) had only elementary education. Patients with abnormal AMT r esults spent more time outside the intended therapeutic ranges than 40 matched controls (20.9% of the observed time vs 13.7%, P < 0.0001; od ds ratio 1.68, CI 1.53-1.84). Unsuspected reduction of mental ability or attention levels was found in a number of elderly patients receivin g OAT; these patients presented longer periods of either under- or ove r-anticoagulation and were, therefore, exposed to a higher risk of thr ombotic or bleeding complications. Anticoagulation clinics would be ad vised to assess mental abilities in elderly patients before starting O AT.