OBJECTIVES:

To determine whether geriatric conditions and functional impairment are independent risk factors for adverse drug events (ADEs).

DESIGN:

Prospective cohort study.

SETTING:

Veterans Affairs Medical Center.

PARTICIPANTS:

Three hundred seventy-seven veterans aged 65 and older and taking five or more medications.

MEASUREMENTS:

Geriatric conditions and functional status were assessed using participant interviews and structured assessments at study baseline. ADEs were elicited during participant interviews 3 and 12 months after study enrollment using validated methods.

RESULTS:

The strong majority (97%) of participants were male, with a mean age of 74 ± 5; 123 (33%) had one or more dependencies in instrumental activities of daily living (IADLs). Over the 1-year study period, 126 participants (33%) developed 167 ADEs. Upon multivariable analysis, risk of ADEs was not associated with any of the geriatric conditions that there was sufficient power to evaluate, including IADL function, cognitive impairment, depression, visual impairment, incontinence, constipation, and a summative measure of geriatric burden comprising the above and history of falls or gait instability. In exploratory analyses, the strongest factor associated with ADEs was the number of drugs added to a participant's medication regimen during the 1-year study period (incidence rate ratio 1.11 per each added drug, 95% confidence interval=1.03-1.19).

CONCLUSION:

Common geriatric conditions and IADL function were not associated with ADEs in a predominantly male, older veteran population. Although it is important to consider the unique circumstances of each participant, excessive caution in prescribing to older adults with these geriatric conditions may not be warranted.

© 2011, Copyright the Authors. Journal compilation © 2011, The American Geriatrics Society.