Age as a Risk Factor for Injury and Error Associated with Drug Use

Session number: 1102

Abstract title: Age as a Risk Factor for Injury and Error Associated with Drug Use

Author(s):
JR Nebeker - VA Salt Lake City GRECC, University of Utah
JF Hurdle - VA Salt Lake City GRECC, University of Utah
JM Hoffman - VA Salt Lake City GRECC
BS Roth - VA Salt Lake City GRECC
CR Weir - VA Salt Lake City GRECC, University of Utah

Objectives: The VA has been a leader in research of adverse drug events (ADEs) among older patients. Research in both veteran and non-veteran settings has generally not shown age to be a risk factor for ADEs despite commonly held views to the contrary. This analysis was undertaken to understand the association of age with 1) the risk of suffering an ADE, 2) the risk of suffering an ADE due to an error in patient care, 3) the excess utilization consequent to an ADE, 4) patterns of ADEs.

Methods: Prospective cohort study in the Salt Lake City VAMC inpatient setting. Research pharmacists reviewed 937 of 2,306 randomly sampled admissions over four months by examining information available in the Computerized Patient Record System (CPRS). ADE reports were confirmed by a panel of MDs, PharmDs, and an RN.

Results: 1) Consistent with other studies the mean age of patients having or not having at least one ADE was not different. However, older patients (65+) more often suffered multiple ADEs and had on average 1.5 times more ADEs than younger patients (p=0.0002). When adjusted for length of stay (LOS) an increase in age by one year was associated with a 1.3% increased risk of an ADE (p=0.005). 2) Older patients vs. younger patients were much more likely to suffer an ADE attributed to an error (RR=2.0; p=0.005). When adjusted for LOS, an increase in age by one year was associated with a 2.7% increased risk of an ADE due to an error (p=0.002). 3) An ADE suffered by an older patient was associated with more interventions on average (0.79 vs. 0.63; p=0.017). 4) Rates of common ADEs were significantly different in older vs. younger patients.

Conclusions: In an inpatient VAMC setting older patients compared to younger patients have more ADEs, are twice as likely to have an ADE associated with error, require more interventions due to ADEs, and suffer different types of ADEs.

Impact statement: Older patients present a high-risk population that could justify special interventions to prevent ADEs. Further research is needed to assess why older patients are at double the risk of an ADE due to an error.