title: Unintended effects of a computerized physician order entry nearly hard-stop alert to prevent a drug interaction: a randomized controlled trial.
abstract: BACKGROUND
  The effectiveness of computerized physician order entry (CPOE) systems has been modest, largely because clinicians frequently override electronic alerts.
  
  
  METHODS
  To evaluate the effectiveness of a nearly "hard stop" CPOE prescribing alert intended to reduce concomitant orders for warfarin and trimethoprim-sulfamethoxazole, a randomized clinical trial was conducted at 2 academic medical centers in Philadelphia, Pennsylvania. A total of 1981 clinicians were assigned to either an intervention group receiving a nearly hard stop alert or a control group receiving the standard practice. The study duration was August 9, 2006, through February 13, 2007.
  
  
  RESULTS
  The proportion of desired responses (ie, not reordering the alert-triggering drug within 10 minutes of firing) was 57.2% (111 of 194 hard stop alerts) in the intervention group and 13.5% (20 of 148) in the control group (adjusted odds ratio, 0.12; 95% confidence interval, 0.045-0.33). However, the study was terminated early because of 4 unintended consequences identified among patients in the intervention group: a delay of treatment with trimethoprim-sulfamethoxazole in 2 patients and a delay of treatment with warfarin in another 2 patients.
  
  
  CONCLUSIONS
  An electronic hard stop alert as part of an inpatient CPOE system seemed to be extremely effective in changing prescribing. However, this intervention precipitated clinically important treatment delays in 4 patients who needed immediate drug therapy. These results illustrate the importance of formal evaluation and monitoring for unintended consequences of programmatic interventions intended to improve prescribing habits.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00870298.
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6021, USA. bstrom@exchange.upenn.edu
authors.forename: Brian L
authors.initials: BL
authors.lastname: Strom
authors.forename: Rita
authors.initials: R
authors.lastname: Schinnar
authors.forename: Faten
authors.initials: F
authors.lastname: Aberra
authors.forename: Warren
authors.initials: W
authors.lastname: Bilker
authors.forename: Sean
authors.initials: S
authors.lastname: Hennessy
authors.forename: Charles E
authors.initials: CE
authors.lastname: Leonard
authors.forename: Eric
authors.initials: E
authors.lastname: Pifer
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D003658:Decision Making, Computer-Assisted; D020000:Decision Support Systems, Clinical; D004347:Drug Interactions; D011307:Drug Prescriptions / Q000592:standards*; D004360:Drug Therapy, Computer-Assisted / Q000592:standards*; D055695:Electronic Prescribing; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control; D006801:Humans; D050316:Medical Order Entry Systems; D008508:Medication Errors / Q000517:prevention & control*; D008510:Medication Systems, Hospital / Q000639:trends; D016017:Odds Ratio; D015143:Philadelphia; D017010:Reminder Systems; D013997:Time Factors; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage / Q000009:adverse effects; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D000890:Anti-Infective Agents; D000925:Anticoagulants; D014859:Warfarin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination