371 Are Elderly Females At Particular Risk For Drug Related Harm? A National Pharmacoepidemiological Study On Potentially Inappropriate Prescribing For The Elderly Home-Dwelling Population In Norway

Nyborg G, Straand J, Brekke M
Aims: Elderly often use several drugs on a regular basis, although there is limited evidence on both medications effects and side-effects in this age group, especially under circumstances of co-morbidities and polypharmacy. Using a recently developed list of explicit criteria for pharmacological inappropriateness, we wanted to explore the prevalence of potentially inappropriate medication use among Norwegian elderly out-patients.
Material and methods: A pharmacoepidemiological retrospective cross-sectional survey based on data from the Norwegian Prescription Database (NorPD) on all prescriptions dispensed by Norwegian pharmacies to home dwelling elderly > 70 years in Norway in 2008, a total of 11,491,065 prescriptions from 24,540 prescribers to 445,900 individuals (58.9% females), with patient-, prescriber-, and substance/amount-information. We applied the NORGEP criteria in a computerized program to assess the level of potentially inappropriate prescriptions (PIP).
Results: According to our criteria, 34.8 % were exposed to at least one PIP, among them 66.4 % female. 59.9 % of PIP represented psychoactive substances. Median number of different drugs to each individual was 7 (Interquartile range 4 to 10, max 45). Among the one fifth using >10 different drugs, two thirds had at least one PIP. Adjusted for differences in age distribution, number of prescribers involved, and the number of substances dispensed for each individual, women were still more frequently exposed to PIP than men, with an odds ratio=1.6. OR for PIP for psychoactive substances was 1.9 for women vs. men, but increased with age for men and decreased for women.
Conclusions: About one third of the elderly Norwegian population is exposed to PIP, and elderly women seem to be at particular risk. Further research is needed to explore the clinical significance of this considerable amount of PIP, including the gender differences revealed here.
Are Elderly Females At Particular Risk For Drug Related Harm? A National Pharmacoepidemiological Study on Potentially Inappropriate Prescribing for the Elderly Home-Dwelling Population in Norway