Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Jul 18;7(3):E446-E453.
doi: 10.9778/cmajo.20180190. Print 2019 Jul-Sep.

Repeat adverse drug events associated with outpatient medications: a descriptive analysis of 3 observational studies in British Columbia, Canada

Corinne M Hohl  1 , Stephanie A Woo  2 , Amber Cragg  2 , Maeve E Wickham  2 , Christine Ackerley  2 , Frank Scheuermeyer  2 , Diane Villanyi  2
Affiliations

Repeat adverse drug events associated with outpatient medications: a descriptive analysis of 3 observational studies in British Columbia, Canada

Corinne M Hohl et al. CMAJ Open. .

Abstract

Background: Adverse drug events are an important cause of preventable emergency department visits and hospital admissions. We examined repeat adverse drug events associated with outpatient medications resulting in acute care utilization.

Methods: This descriptive analysis combined data from 3 prospective multicentre observational studies, in which clinical pharmacists and physicians independently evaluated patients who visited the emergency department for adverse drug events in 3 hospitals in British Columbia. During these studies, an independent committee adjudicated all discordant and uncertain cases using a standardized algorithm. For the current study, we retrospectively reviewed the medical and research records of all patients 19 years of age and older who had been diagnosed with an adverse drug event during the primary studies to determine the proportion of repeat events. We used multivariable logistic regression to identify factors associated with repeat events; we adjusted for clustering at the hospital level for patient-level analyses and at the patient level for event-level analyses.

Results: Among 12 977 patients, 1178 were diagnosed with 1296 adverse drug events at the point of care. Of these events, 32.5% (421 of 1296; 95% confidence interval [CI] 29.8%-35.1%) were repeat events, of which 75.3% (317 of 421; 95% CI 71.1%-79.5%) were deemed probably or definitely preventable as re-exposure to the culprit medication or repeat withdrawal of an indicated medication was inconsistent with best medical practice. Patients presenting with repeat events were more likely to have renal failure (odds ratio [OR] 2.01; 95% CI 1.32%-3.07%) or a mental health diagnosis (OR 1.39; 95% CI 1.02%-1.88%).

Interpretation: A high proportion of adverse drug events were repeat events, most of which were deemed preventable. Interventions to ensure that care providers are aware of previously diagnosed adverse drug events when prescribing or dispensing need to be developed and evaluated and may reduce unintentional re-exposures to previously harmful medications.

PubMed Disclaimer

Conflict of interest statement

Competing interests: The authors’ research group is developing a software application called ActionADE, which will enable standardized documentation of adverse drug events by front-line clinicians and communication of this information to a central medication dispensing database. No other competing interests were declared.

Figures

Figure 1:
Figure 1:
Flow diagram of patients through the study. Note: ADE = adverse drug event, ED = emergency department.
See this image and copyright information in PMC

References

    1. Budnitz DS, Lovegrove MC, Shehab N, et al. Emergency hospitalizations for adverse drug events in older Americans. N Engl J Med. 2011;365:2002–12. - PubMed
    1. Hohl CM, Dankoff J, Colacone A, et al. Polypharmacy, adverse drug-related events, and potential adverse drug interactions in elderly patients presenting to an emergency department. Ann Emerg Med. 2001;38:666–71. - PubMed
    1. Zed PJ, Abu-Laban RB, Balen RM, et al. Incidence, severity and preventability of medication-related visits to the emergency department: a prospective study. CMAJ. 2008;178:1563–9. - PMC - PubMed
    1. Research Priority Setting Working Group. Global priorities for research in patient safety. 1st ed. Geneva: World Health Organization; 2008.
    1. Medication without harm: WHO Global Patient Safety Challenge. Geneva: World Health Organization; 2017.