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A cross-sectional observational study of high override rates of drug allergy alerts in inpatient and outpatient settings, and opportunities for improvement
  1. Sarah Patricia Slight1,*,
  2. Patrick E Beeler2,*,
  3. Diane L Seger3,
  4. Mary G Amato4,5,
  5. Qoua L Her5,
  6. Michael Swerdloff5,
  7. Olivia Dalleur6,
  8. Karen C Nanji7,
  9. InSook Cho8,9,
  10. Nivethietha Maniam5,
  11. Tewodros Eguale5,
  12. Julie M Fiskio10,
  13. Patricia C Dykes11,
  14. David W Bates5
  1. 1Department of Pharmacy Practice, Durham University, Durham, UK
  2. 2Research Center for Medical Informatics, University Hospital Zurich, Zurich, Switzerland
  3. 3Research Center for Medical Informatics, Partners Healthcare, Boston, Massachusetts, USA
  4. 4Department of Pharmacy, MCPHS University, Boston, Massachusetts, USA
  5. 5Division of General Internal Medicine and Primary Care, Brigham and Women's Hospital, Boston, Massachusetts, USA
  6. 6Louvain Drug Research Institute, Universite catholique de Louvain (UCL), Belgium, Belgium
  7. 7Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, USA
  8. 8Department of Nursing, Inha University, Incheon, Korea, Republic of
  9. 9Public Health Department, Harvard Medical School, Boston, Massachusetts, USA
  10. 10Division of General Internal Medicine and Primary Care, Partners Healthcare, Boston, Massachusetts, USA
  11. 11Division of General Internal Medicine & Primary Care, Brigham and Women's Hospital, Boston, Massachusetts, USA
  1. Correspondence to Dr Sarah Patricia Slight, Department of Pharmacy Practice, Durham University, Holliday Building, Queens Campus, Durham TS17 6BH, UK; s.p.slight{at}


Objectives To evaluate how often and why providers overrode drug allergy alerts in both the inpatient and outpatient settings.

Design A cross-sectional observational study of drug allergy alerts generated over a 3-year period between 1 January 2009 and 31 December 2011.

Setting A 793-bed tertiary care teaching affiliate of Harvard Medical School and 36 primary care practices.

Participants Drug allergy alerts were displayed for a total of 29 420 patients across both settings.

Main outcome measures Proportion of drug allergy alerts displayed and overridden, proportion of appropriate overrides, proportion of overrides in each medication class, different reasons for overriding and types of reactions overridden.

Results A total of 158 023 drug allergy alerts were displayed, 131 615 (83%) in the inpatient setting and 26 408 (17%) in the outpatient setting; 128 157 (81%) of which were overridden. A random sample of inpatient (n=200, 0.19%) and outpatient (n=50, 0.25%) alert overrides were screened for appropriateness, with >96% considered appropriate. Alerts for some drug classes, such as ‘non-antibiotic sulfonamides’, were overridden for >81% of prescriptions in both settings. The most common override reason was patient has taken previously without allergic reaction. In the inpatient setting alone, 70.9% of alerts that warned against the risk of anaphylaxis were overridden.

Conclusions The information contained in patients’ drug allergy lists needs to be regularly updated. Most of the drug allergy alerts were overridden, with the majority of alert overrides in the subsample considered appropriate. Some of the rules for these alerts should be carefully reviewed and modified, or removed. Further research is needed to understand providers’ overriding of alerts that warned against the risk of ‘anaphylaxis’, which are more concerning with respect to patient safety.

  • Decision support, computerized
  • Health services research
  • Medication safety

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  • * SPS and PEB contributed equally and are joint first authors.

  • Twitter Follow David Bates at @dbatessafety

  • Contributors DWB conceived this study. DLS, MA, IC and KCN reviewed the patient charts, JMF extracted the data, and PEB processed these data and conducted the analyses. SPS led the writing of this manuscript with all coauthors commenting on subsequent drafts. All authors gave their approval for the final version to be published. SPS and DWB act as guarantors.

  • Funding Agency for Healthcare Research and Quality (AHRQ) (#U19HS021094). Dr Beeler was supported by the Swiss National Science Foundation.

  • Competing interests None declared.

  • Ethics approval The necessary approvals were obtained to access these data from the Partners Human Research Committee (PHRC), which is the Institutional Review Board (IRB) of Partners Research Management at Partners HealthCare.

  • Provenance and peer review Not commissioned; externally peer reviewed.