Potential drug-disease interactions in frail, hospitalized elderly veterans.

BACKGROUND

Drugs can improve quality of life for many older people, but they may cause adverse health outcomes (eg, drug-disease interactions) if used inappropriately.

OBJECTIVE

To determine the prevalence of potential drug-disease interactions as defined by explicit criteria and examine associations between sociodemographic and health status variables and potential drug-disease interactions.

METHODS

The study design was cross-sectional. We evaluated 397 frail elderly inpatients from the Geriatric Evaluation and Management trial conducted at 11 Veterans Affairs Medical Centers. Drug-disease interactions were defined using explicit criteria from consensus expert panels of geriatricians from the US and Canada.

RESULTS

Overall, 159 (40.1%) patients had one or more potential drug-disease interaction. The most common potential interactions were calcium-channel blockers and heart failure (12.3%) and beta-blockers and diabetes (6.8%). Multivariable logistic regression analyses revealed that age > or =75 years (adjusted OR 2.43; 95% CI 1.52 to 3.88), being married (adjusted OR 1.77; 95% CI 1.11 to 2.82), comorbidity index defined by Charlson method (adjusted OR 1.19; 95% CI 1.05 to 1.34), and use of multiple prescription drugs (5-8: adjusted OR 4.17; 95% CI 1.96 to 8.88, > or =9: adjusted OR 9.22; 95% CI 4.26 to 19.95), were significantly (p < 0.05) associated with having one or more potential drug-disease interaction.

CONCLUSIONS

Potential drug-disease interactions are common in hospitalized elderly patients and are related to specific sociodemographic and health status factors. Further research is needed to examine the relationship between health outcomes and drug-disease interactions.