Inappropriate Drugs in Elderly Patients with Severe Cognitive Impairment: Results from the Shelter Study

Background: It has been estimated that Nursing Home (NH) residents with impaired cognitive status receive an average of seven to eight drugs daily. The aim of this study was to determine prevalence and factors associated with use of inappropriate drugs in elderly patients with severe cognitive impairment living in NH in Europe. Methods: Cross-sectional data from a sample of 1449 NH residents with severe cognitive impairment, participating in the Services and Health for Elderly in Long TERm care (SHELTER) study were analysed. Inappropriate drug use was defined as the use of drugs classified as rarely or never appropriate in patients with severe cognitive impairment based on the Holmes criteria published in 2008. Results: Mean age of participating residents was 84.2 +/- 8.9 years, 1087 (75.0%) were women. Inappropriate drug use was observed in 643 (44.9%) residents. Most commonly used inappropriate drugs were lipid-lowering agents (9.9%), antiplatelet agents (excluding Acetylsalicylic Acid - ASA -) (9.9%), acetylcholinesterase, inhibitors (7.2%) and antispasmodics (6.9%). Inappropriate drug use was directly associated with specific diseases including diabetes (OR 1.64; 95% CI 1.21-2.24), heart failure (OR 1.48; 95% CI 1.04-2.09), stroke (OR 1.43; 95% CI 1.06-1.93), and recent hospitalization (OR 1.69; 95% CI 1.20-2.39). An inverse relation was shown between inappropriate drug use and presence of a geriatrician in the facility (OR 0.55; 95% CI 0.39-0.77). Conclusion: Use of inappropriate drugs is common among older EU NH residents. Determinants of inappropriate drug use include comorbidities and recent hospitalization. Presence of a geriatrician in the facility staff is associated with a reduced rate of use of these medications.