DETECTING PATIENTS WITH ALZHEIMERS-DISEASE SUITABLE FOR DRUG-TREATMENT - COMPARISON OF 3 METHODS OF ASSESSMENT

Background. Therapy to enhance cholinergic function in the brain is un der evaluation for the treatment of alzheimers disease. Tetrahydroamin oacridine (tacrine) has recently received a product licence in the Uni ted States of America for the treatment of alzheimers disease, and the licence application in the United Kingdom will shortly be reviewed. I t is therefore possible that this drug will become available for use i n the UK in due course. There will then be a need for screening proced ures for a large number of elderly patients to decide whether or not t hey have dementia and, if so, whether it is the result of alzheimers d isease and is suitable for treatment with the new drug. Method. A tota l of 246 patients aged 75 years or over in two general practices in Br istol were assessed to investigate the potential workload such screeni ng would engender. Three different assessment schedules for the diagno sis of dementia were compared - the mini-mental state examination, the Kew test, and the abbreviated mental test score. Results. None of the assessment schedules was found to be particularly onerous, with media n times for administration of five, three and two minutes, respectivel y. A score of 23 or less on the mini-mental state examination was take n as the main cut-off point for further evaluation. Sixty six patients obtained this score - in 25 the low score reflected factors other tha n dementia, and 11 others declined further assessment. Of the remainin g 30 patients only four had probable alzheimers disease at an appropri ate level of severity for treatment, and lived with a carer who could ensure compliance and monitor side effects. Two of these patients were receiving conflicting medical treatment and a third declined therapy, leaving only one person for whom treatment could be prescribed. Concl usion. It seems likely that of those medically suitable for treatment, it may not be possible to prescribe tacrine for an appreciable propor tion. Nevertheless, all potential patients should be screened as the p rocedures involved are not onerous and at least some of those found su itable for treatment are likely to benefit from this new approach.