P&T News: May/June 2000

The Use of a Computer Based Decision Support System in the Prevention of Adverse Drug Events at the University of Iowa Hospitals and Clinics

Tim G. Burke, Pharm.D. and Paul W. Abramowitz, Pharm.D.
Peer Review Status: Internally Peer Reviewed by Carol Scott-Connor, M.D., Professor and Head, Department of Surgery

Recently, there have been a number of articles in both the professional and lay literature discussing the consequences of medication misadventures that occur while taking care of the hospitalized patient. These misadventures are described as adverse drug reactions or adverse drug events.1-8 An adverse drug reaction (ADR) as defined by the World Health Organization is "any noxious, unintended, or undesired effect of a drug at doses used in humans." The definition of an adverse drug event (ADE) is "an injury resulting from the administration of a drug." Thus, ADEs would include errors and overdoses while the definition of an ADR would not.1 This article will briefly review some of these articles and discuss the computer alert system employed at the UIHC that is used to identify potential ADRs and ADEs.

Literature Reports
The November 1999 Institute of Medicine (IOM) report, "To Err is Human: Building a Safer Health System," states that 44,000 to 98,000 deaths per year are due to medical errors. More than 7,000 of these are due to medication errors. This number exceeds the number of deaths due to workplace injuries. The report goes on to state that the majority of medical errors result from basic flaws in the health system organization and not from individual recklessness.2

A recently published meta-analysis of 39 prospective studies dealing with ADRs presented incidence data with numbers that were even higher than the IOM report. The meta-analysis assessed the incidence of serious and fatal drug reactions in hospitalized patients from 1966 to 1996. Patients who were admitted to the hospital with an ADR, as well as patients that experienced an ADR while in the hospital, were included. Serious ADRs occurred in 6.3% of the patients with 0.32% having a fatal ADR. The authors, using the numbers derived from their meta-analysis, went on to state that in 1994 an estimated 2.2 million hospitalized patients experienced an ADR. Of these, approximately 106,000 died. This would place ADRs as the 4th to 6th leading cause of death in the United States.1

A prospective study of 4031 adult admissions to 11 medical and surgical units found 6.5 ADEs and 5.5 potential ADEs per 100 admissions. Of these, 1% were fatal, 12% life threatening, and 30% serious. Twenty-eight percent of all ADEs were considered preventable. Overall, 42% of the serious or life threatening ADEs were considered preventable. Sources of ADEs included ordering, administration, transcription, and dispensing.3 The cost for the preventable ADEs was $4,685 per admission with an increased length of stay of 4.6 hospital days. This translated into an annual hospital cost of $2.8 million.4

Another study found an ADE rate of 2.43 per 100 admissions. Hospital length of stay was increased 1.91 days per ADE with an additional cost of $2262. While this study did not differentiate between preventable ADEs and those that could not have been prevented, the authors assumed that if 50% of the ADEs were preventable there would be a decrease of 450 hospital days per year. The annual savings would be $500,000.5

Lesar et al identified a medication error rate of 4% in one hospital. Factors contributing to the errors included the failure to adjust doses for renal and hepatic function, drug allergies, drug name confusion, and incorrect doses. These errors were due to lack of drug knowledge in 30% of the cases, patient factors (such as pre-existing allergies) in 30% of the cases, and calculation errors in 40%.6

In another study, Leape et al evaluated all admissions to 11 medical and surgical units in two tertiary care hospitals over a six-month period. During this period, 334 errors were detected as the causes of 264 preventable ADEs and potential ADEs. Sixteen major systems failures were identified as the underlying causes of the errors. These included failure to disseminate drug knowledge, inadequate availability of patient information such as laboratory tests and allergies, and lack of medication dose checking. The authors concluded that 78% of errors leading to an ADE were due to system failures that could be prevented by better information systems.7

Recommendations To Improve Medication Safety
The American Hospital Association makes a number of recommendations for reducing medication errors. These recommendations are listed in Table 1.8 These practices have been implemented at the UIHC or are currently in the process of implementation.

One recommendation is to increase the use of computer systems in the medication use process. This includes computer screening for duplicate drug entries, patient allergies, potential drug interactions, drug/lab interactions, and dose ranges.

A complete list of the current rules and the clinical conditions monitored by pharmacy is depicted in Tables 3-5 (not shown here).

Conclusions and Future Endeavors
In conclusion, the use of technology is one of the tools employed at UIHC to decrease the opportunity for ADEs. Our goal is to reduce the incidence of ADEs to zero, and we will continue to use technology, as it develops, to achieve the goal of zero preventable ADEs. In the future, alerts will go directly to the prescriber during the medication order entry process.

References
1. JAMA 1998;279:1200-5.
2. To Err Is Human: Building A Safer Health System Institute Of Medicine Report, http://www.nap.edu/books/0309068371/html/
3. JAMA 1995;274:29-34.
4. JAMA 1997;277:307-11.

Table 1. American Hospital Association Recommendations on Successful Practices for Improving Medication Safety

Short Term Goals

  • Fully implement unit dose systems
  • Limit the variety of devices and equipment
  • Develop special procedures and written protocols for high-alert drugs
  • Ensure the availability of up-to-date drug information
  • Educate staff about medications and medication errors
  • Educate patients
  • Ensure the availability of pharmacy expertise
  • Have a pharmacist available 24 hours a day
  • Consider placement of pharmacists directly on the patient care units
  • Standardize prescribing and communication practices

Long Term Goals

  • Develop a voluntary, non-punitive system to monitor and report adverse drug events
  • Increase the use of computers in the medication administration system
  • Institute 24-hour pharmacy service  

Pharmacy and Therapeutics Subcommittee Actions

Drugs Added to Stock

ALOSETRON Tablets: I mg Alosetron (Lotronex[R] - Glaxo Wellcome) is a selective 5-HT3, receptor antagonist indicated for the treatment of irritable bowel syndrome in women whose predominant bowel symptom is diarrhea. Efficacy in men was not demonstrated during dose-ranging studies. NOTE: Prescribing is restricted; the first order/prescription must be written by an attending staff physician from Adult Gastroenterology.

DIAZEPAM Rectal Gel: 5 mg, 10 mg Diazepam rectal gel (Diastat[R] - Athena) is indicated for the management of seizures in patients who are on stable regimens of antiepileptic drugs but require intermittent use of diazepam to control bouts of increased seizure activity. NOTE: The prescribing of diazepam rectal gel is restricted to Hospital School and ambulatory care patients.

LEVONORGESTROL Tablet: 0.75 mg Levonorgestrol 0.75 mg tablets (Plan B[R] - Women's Capital Corporation) are indicated for emergency contraception. The first tablet is taken within 72 hours of unprotected intercourse; the second tablet is taken 12 hours later.

PIOGLITAZONE Tablets: 15 mg, 30 mg, 45 mg Pioglitazone (Acto[R] - Lilly/Takeda) is indicated for the treatment of type 2 diabetes. It improves glycemic control by decreasing insulin resistance; therefore, it is ineffective in patients with type I diabetes. Liver function test monitoring must be performed prior to the initiation of pioglitazone therapy, every 2 months for the first year of therapy, and periodically thereafter.

RAPACURONIUM Injection: 100 mg per vial Rapacuronium (Raplon[R] - Organon) is a nondepolarizing neuromuscular blocking agent indicated as an adjunct to general anesthesia to facilitate tracheal anesthesia and to provide skeletal muscle relaxation during surgical procedures.

NOTE: Restricted to prescribing by Anesthesia and medical staff who have been credentialled to administer neuromuscular blocking agents

ADDITIONAL ACTIONS

OXYCODONE 80 mg SUSTAINED-RELEASE TABLET An 80 mg sustained-release tablet has been added to stock.

PREDNISOLONE ORAL SYRUP A I mg/ml oral syrup (PediaPred[R]) has been added to stock.

Note: The cost following each brief monograph is the UIHC acquisition cost.

NAME CHANGE

INAMRINONE In order to avoid name confusion between amrinone and amiodarone, the official name of amrinone will be changed to inamrinone. The name change will become official on July 1, 2000.

DRUGS DELETED FROM STOCK

ACARBOSE (PRECOSE[R]) TABLETS Deleted due to low use and the addition of a better tolerated alpha-glucosidase inhibitor, miglitol (Glyset[R]).

AMPHOTERICIN B 100 mg/ml ORAL SUSPENSION Discontinued by the manufacturer. An oral suspension can be extemporaneously compounded by Pharmacy, if needed.

CALCIFEDIOL 50 mcg CAPSULES Discontinued by the manufacturer; a 20 mcg capsule is available.

DEXAMETHASONE 1.5 mg TABLETS Deleted due to low use; 0.5 mg, 0.75 mg and I mg tablets are available.

TROGLITAZONE (REZULIN[R]) TABLETS Withdrawn from the market due to reports of liver failure and death. Rosiglitazone and pioglitazone are available.

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