Antiepileptic drug use in community-dwelling and institutionalized elderly: a nationwide study of over 1 300 000 older people

Abstract

To investigate whether institutionalization is associated with the use of antiepileptic drugs (AEDs) and to compare the association between use of AEDs and psychotropics in community-dwelling and institutionalized elderly, after adjustment for age, sex and co-morbidity (i.e. number of other drugs). We analyzed data on age, sex and dispensed drugs for individuals aged ≥65 years registered in the Swedish Prescribed Drug Register from July to September 2008, record-linked to the Swedish Social Services Register (n = 1,345,273: 1,258,565 community-dwelling and 86 708 institutionalized elderly). Multivariate logistic regression analysis was used to analyze whether institutionalization and use of psychotropics (i.e. antipsychotics, anxiolytics, hypnotics/sedatives and antidepressants) were associated with the use of AEDs. AEDs were used by 2% of the community-dwelling and 9% of the institutionalized elderly. The most commonly used AEDs were carbamazepine, gabapentin, pregabalin, valproic acid and lamotrigine. Institutionalization was strongly associated with AED use (OR(adjusted) = 3.98; 95% CI 3.86-4.10). In community-dwelling elderly, AED use was associated with an increased probability of use of all types of psychotropics. However, among institutionalized elderly, the associations between use of AEDs and psychotropics showed a mixed pattern. AED use seems to be common among Swedish institutionalized elderly, and institutionalization is a strong determinant of AED use. Our results may also indicate an off-label prescribing of AEDs as an alternative to psychotropics in the institutional setting. This finding needs to be confirmed by others and evaluated with respect to outcomes of this treatment in institutionalized elderly.