Association Between Psychotropic and Cardiovascular Iatrogenic Alerts and Risk of Hospitalizations in Elderly People Treated for Dementia: A Self-Controlled Case Series Study Based on the Matching of 2 French Health Insurance Databases

Abstract

Background: Elderly people are at risk of repeated hospitalizations, some of which may be drug related and preventable. In 2011, a group of French healthcare experts selected 5 iatrogenic alerts (IAs), based on criteria identified in a literature search and from their professional experience, to assess the appropriateness of medication in elderly patients.

Objectives: Our objective was to examine the association between hospitalizations and IAs in elderly patients treated for Alzheimer disease who are particularly sensitive to adverse drug events.

Design: A 2-year (January 1, 2011, to December 31, 2012) longitudinal national database study, with a study design similar to self-controlled case series, was performed to analyze data on drug prescriptions and hospitalization. IAs were defined as (1) long half-life benzodiazepine; (2) antipsychotic drugs in patients with Alzheimer disease; (3) co-prescription of 3 or more psychotropic drugs; (4) co-prescription of 2 or more diuretics; and (5) co-prescription of 4 or more antihypertensive drugs. Data were obtained by matching of 2 French National Health Insurance Databases.

Setting: France.

Participants: All affiliates, aged ≥75 years, receiving treatment for Alzheimer disease, alive on January 1, 2011 were included.

Measurements: We calculated the relative increase in the number of hospitalizations in patients with IAs. The analysis was performed over four 6-month periods.

Results: A total of 10,754 patients were included. During the periods with IAs, hospitalization rates increased by 0.36/year compared with 0.23/year in the periods without for the same patient, and the number of hospitalizations doubled [proportional fold change = 1.9, 95% confidence interval (1.8, 2.1)]. We estimated that 22% [95% confidence interval (20%, 23%)] of all hospitalizations were associated with IAs, 80% of which were due to psychotropic IAs.

Conclusions: The IAs could be used as a simple and clinically relevant tool by prescribing physicians to assess the appropriateness of the prescription in elderly patients treated for Alzheimer disease.

Keywords: Iatrogenic alert; adverse drug event; self-controlled analysis.