title: Drug safety alert generation and overriding in a large Dutch university medical centre.
abstract: OBJECTIVE
  To evaluate numbers and types of drug safety alerts generated and overridden in a large Dutch university medical centre.
  
  
  METHODS
  A disguised observation study lasting 25 days on two internal medicine wards evaluating alert generation and handling of alerts. A retrospective analysis was also performed of all drug safety alerts overridden in the hospital using pharmacy log files over 24 months.
  
  
  RESULTS
  In the disguised observation study 34% of the orders generated a drug safety alert of which 91% were overridden. The majority of alerts generated (56%) concerned drug-drug interactions (DDIs) and these were overridden more often (98%) than overdoses (89%) or duplicate orders (80%). All drug safety alerts concerning admission medicines were overridden.Retrospective analysis of pharmacy log files for all wards revealed one override per five prescriptions. Of all overrides, DDIs accounted for 59%, overdoses 24% and duplicate orders 17%. DDI alerts of medium-level seriousness were overridden more often (55%) than low-level (22%) or high-level DDIs (19%). In 36% of DDI overrides, it would have been possible to monitor effects by measuring serum levels. The top 20 of overridden DDIs accounted for 76% of all DDI overrides.
  
  
  CONCLUSIONS
  Drug safety alerts were generated in one third of orders and were frequently overridden. Duplicate order alerts more often resulted in order cancellation (20%) than did alerts for overdose (11%) or DDIs (2%). DDIs were most frequently overridden. Only a small number of DDIs caused these overrides. Studies on improvement of alert handling should focus on these frequently-overridden DDIs.
authors: Department of Hospital Pharmacy, Erasmus University Medical Centre, Rotterdam, the Netherlands. i.vandersijs@erasmusmc.nl
authors: Heleen
authors: H
authors: van der Sijs
authors: Alexandra
authors: A
authors: Mulder
authors: Teun
authors: T
authors: van Gelder
authors: Jos
authors: J
authors: Aarts
authors: Marc
authors: M
authors: Berg
authors: Arnold
authors: A
authors: Vulto
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D020000:Decision Support Systems, Clinical; D004347:Drug Interactions; D062787:Drug Overdose / Q000517:prevention & control; D011307:Drug Prescriptions; D004360:Drug Therapy, Computer-Assisted / Q000706:statistics & numerical data; D006757:Hospital Units; D006801:Humans; D007388:Internal Medicine; D050316:Medical Order Entry Systems / Q000706:statistics & numerical data; D008508:Medication Errors / Q000517:prevention & control* / Q000706:statistics & numerical data; D009426:Netherlands; D010607:Pharmacy Service, Hospital / Q000706:statistics & numerical data; D017010:Reminder Systems / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013997:Time Factors