Objective: To assess the extent of inappropriateness of drug use in an older nondemented and demented population.
Design: Descriptive analysis based on data from a sample of older subjects age 81 years and older. Data were collected from the second follow-up conducted in 1994-1996.
Setting: A population-based study of the Kungsholmen project in Stockholm, Sweden.
Participants: Drug information was obtained from 681 subjects with a mean age of 86.9 years. The subjects were predominantly women (78%). Thirteen percent resided in institutions and 27.6% were diagnosed with dementia.
Measurements: Dementia diagnosis based on DSM III-R. Criteria for inappropriateness of drug use: use of drugs with potent anticholinergic properties, drug duplication, potential drug-drug and drug-disease interactions, and inappropriate drug dosage.
Results: The mean number of drugs used was 4.6: 4.5 drugs for nondemented and 4.8 for demented subjects. Nondemented subjects more commonly used cardiovascular-system drugs and demented subjects used nervous-system drugs. Demented subjects were more commonly exposed to drug duplication and to drugs with potent anticholinergic properties, both involving the use of psychotropic drugs. Nondemented subjects were more commonly exposed to potential drug-disease interactions, mostly with the use of cardiovascular drugs. The most common drug combination leading to a potential interaction was the use of digoxin with furosemide, occurring more frequently among nondemented subjects. The most common drug-disease interaction was the use of beta-blockers and calcium antagonists in subjects with congestive heart failure. The doses of drugs taken by both nondemented and demented subjects were mostly lower than the defined daily dose.
Conclusion: There was substantial exposure to presumptive inappropriateness of drug use in this very old nondemented and demented population. The exposure of demented subjects to psychotropic drugs and nondemented subjects to cardiovascular drugs reflect the high frequency of prescribing these drugs in this population.