August 11, 2016

Preventable adverse drug reactions

Query 16-03: Preventable adverse drug reactions (ADR) as percentage of total ADRs

This research was funded by the Drug Safety and Effectiveness Network (DSEN) and conducted by the following investigators: Corrine Hohl, Stephanie Woo, Amber Cragg, Maeve Wickham, Diane Villanyi, Frank Scheuermeyer, Jeffrey Hau.

Issue:

  • Adverse drug events are an important and common condition in emergency departments and acute care hospitals and pose a health risk to patients.
  • Adverse drug events are poorly documented in electronic medical records and administrative data increases the likelihood of recurrence due to lack of information continuity between providers and across health sectors and posing a risk to patients.
  • From the perspective of researchers and drug regulators, poor quality data on adverse drug events hinder efforts in post-market drug surveillance and in research in drug safety and effectiveness.

Study aim:

  • To determine the preventability of an adverse drug event, identify contributing factors, determine the ADE-related harm and interventions required, and identify the kind of drug re-exposure that would likely cause a future repeat ADE

Study description:

  • Phase 1, we are conducting a retrospective chart review of patients who were diagnosed with an ADE to determine the preventability of the event, identify contributing factors, determine the ADE-related harm and interventions required, and identify the kind of drug re-exposure that would likely cause a future repeat ADE.
  • Phase 2, we will link phase I data to BC health data (PharmaNet) to determine the proportion of ADE patients that were re-exposed to contraindicated medications.

Study findings:

Phase 1:

  • Data of 1234 patients were studied and 1356 ADEs were found. ADEs due to adverse drug reactions (35%) and non-adherence (19%) were most common, most moderate (65%) or severe (31%) and two-thirds required either major or minor interventions in hospital. 
  • We deemed 64% (95%CI:62-67%) of ADEs to be preventable and 29% (95%CI:26-31%) were repeat events. The most commonly implicated drug classes were coumarin derivatives (9%), and opiate agonists (9%), and common contributing factors included inadequate patient counselling (16%), lack of follow-up after a change in the regimen (12%), and insufficient laboratory monitoring (11%).
  • On multivariable patient-level analyses, mental health diagnoses, diabetes, and a prior ADE to the same drug were associated with patients having preventable ADEs. Diabetes and renal failure were significant in association with patients having repeat ADEs.

Phase 2:

  • We linked phase I data to BC health data (PharmaNet) to determine the proportion of ADE patients that were re-exposed to contraindicated medications.
  • We linked the prospective and chart review data to PharmaNet, BC’s provincial medication dispensing database, and determined the proportion of ADEs in which the patient was re-exposed to the culprit medication after hospital discharge from the index emergency department (ED) visit.

Future work by our team will involve survival analysis regression to examine risk factors for the hazard of re-exposure by modeling the time-to-re-dispensation

Woo SA, Cragg A, Wickham ME, Peddie D, Balka E, Scheuermeyer F, Villanyi D, Hohl CM. Methods for evaluating adverse drug event preventability in emergency department patients. BMC Red Res Methodol. 2018;18:160.

Hohl CM, Woo SA, Cragg A, Wickham ME, Ackerley C, Scheuermeyer F, Villanyi D. Repeat adverse drug events associated with outpatient medications: a descriptive analysis of 3 observational studies in British Columbia, Canada. CMAJ Open. July 2019;7(3):E446-53.

Woo SA, Cragg A, Wickham ME, Villanyi D, Scheuermeyer F, Hau JP, Hohl C. Preventable adverse drug events: Descriptive epidemiology. Br J Clin Pharmacol. 2020 Feb;86(2):291-302. 

Hohl et al. Repeat exposures to culprit drugs contribute to adverse drug events in emergency department patients. 2017 (CAEP abstract).

Hohl et al. Preventable adverse drug events in Canadian emergency departments. 2017 (CAEP abstract).

Woo et al. Factors contributing to the development of adverse drug events treated in emergency departments. 2017 (CAEP abstract).

Wickham et al. Preventable and repeat adverse drug events in Canadian emergency department patients. 2017 (CAHSPR abstract).

Woo et al. Preventable adverse drug events in Canadian emergency departments. 2019 (CAEP abstract).

For more information, contact: Autumn Neville, Research Coordinator. [email protected]