Leape LL, Cullen DJ, Clapp MD, Burdick E, Demonaco HJ, Erickson JI, Bates DW. Pharmacist Participation on Physician Rounds and Adverse Drug Events in the Intensive Care Unit. JAMA. 1999;282(3):267–270. doi:10.1001/jama.282.3.267
Author Affiliations: Department of Health Policy and Management, Harvard School of Public Health (Dr Leape and Ms Burdick); Departments of Anesthesia (Dr Cullen), Pharmacy (Ms Clapp and Mr Demonaco), and Nursing (Ms Erickson), Massachusetts General Hospital; and Division of General Internal Medicine, Brigham and Women's Hospital (Dr Bates), Boston, Mass.
Caring for the Critically Ill Patient Section Editor:Deborah J. Cook, MD, Consulting Editor, JAMA. Advisory Board: David
Bihari, MD; Christian Brun-Buisson, MD; Timothy Evans, MD; John Heffner, MD;
Norman Paradis, MD.
Context Pharmacist review of medication orders in the intensive care unit (ICU)
has been shown to prevent errors, and pharmacist consultation has reduced
drug costs. However, whether pharmacist participation in the ICU at the time
of drug prescribing reduces adverse events has not been studied.
Objective To measure the effect of pharmacist participation on medical rounds
in the ICU on the rate of preventable adverse drug events (ADEs) caused by
Design Before-after comparison between phase 1 (baseline) and phase 2 (after
intervention implemented) and phase 2 comparison with a control unit that
did not receive the intervention.
Setting A medical ICU (study unit) and a coronary care unit (control unit) in
a large urban teaching hospital.
Patients Seventy-five patients randomly selected from each of 3 groups: all admissions
to the study unit from February 1, 1993, through July 31, 1993 (baseline)
and all admissions to the study unit (postintervention) and control unit from
October 1, 1994, through July 7, 1995. In addition, 50 patients were selected
at random from the control unit during the baseline period.
Intervention A senior pharmacist made rounds with the ICU team and remained in the
ICU for consultation in the morning, and was available on call throughout
Main Outcome Measures Preventable ADEs due to ordering (prescribing) errors and the number,
type, and acceptance of interventions made by the pharmacist. Preventable
ADEs were identified by review of medical records of the randomly selected
patients during both preintervention and postintervention phases. Pharmacists
recorded all recommendations, which were then analyzed by type and acceptance.
Results The rate of preventable ordering ADEs decreased by 66% from 10.4 per
1000 patient-days (95% confidence interval [CI], 7-14) before the intervention
to 3.5 (95% CI, 1-5; P<.001) after the intervention.
In the control unit, the rate was essentially unchanged during the same time
periods: 10.9 (95% CI, 6-16) and 12.4 (95% CI, 8-17) per 1000 patient-days.
The pharmacist made 366 recommendations related to drug ordering, of which
362 (99%) were accepted by physicians.
Conclusions The presence of a pharmacist on rounds as a full member of the patient
care team in a medical ICU was associated with a substantially lower rate
of ADEs caused by prescribing errors. Nearly all the changes were readily
accepted by physicians.
In traditional hospital practice most of the burden of drug therapy
decision making falls on the physician. However, studies have shown that physicians
sometimes make errors in prescribing drugs.1,2
While most errors are harmless or are intercepted, some result in adverse
drug events (ADEs). The pharmacist's role in prescribing is typically reactive:
responding to prescription errors long after the decision has been made for
patients about whom he or she has little direct clinical knowledge. Thus,
the specialized knowledge of the pharmacist is not utilized when it would
be most useful: at the time of ordering.
Studies show that pharmacist retrospective review of medication orders
prevents errors.3- 5
However, the pharmacist's impact might be substantially greater if he or she
could provide input earlier, at the time of prescribing. It has been shown
that pharmacist consultation with physicians and others in an intensive care
unit (ICU) resulted in a net saving from reduced drug use of $10,011 in a
3-month period.6 However, we know of no controlled
studies that have evaluated the effect of pharmacist participation on the
key outcome measure of error prevention—the rate of ADEs.
For these reasons, we conducted a controlled clinical trial of the efficacy
of pharmacist participation in physician rounds in a medical ICU as part of
a continuing study of systems changes to prevent ADEs. The ADE rate is higher
among patients in ICUs, both because they have pathophysiological abnormalities
and often receive many drugs.
We asked the following questions: (1) Is pharmacist participation on
rounds associated with a reduction in the rate of preventable ADEs? (2) What
types of interventions does the pharmacist make? and (3) Is pharmacist participation
on ICU rounds accepted by physicians and nurses?
The study was carried out in 2 medical ICUs at Massachusetts General
Hospital, a large tertiary care hospital in Boston, during 2 periods: February
1, 1993, through July 31, 1993 (phase 1, preintervention), and October 1,
1994, through July 7, 1995 (phase 2, postintervention).
unit was a 17-bed medical ICU and the control unit was a 15-bed coronary care
unit (CCU). The average daily census was 13.9 in the medical ICU and 12.9
in the CCU during phase 1 and 12.4 and 11.9, respectively, during phase 2.
Nurse and physician staffing ratios were similar in the 2 units. Patients
in the medical ICU had a range of acute and chronic medical illness other
than primary cardiac disease, while those in the CCU were primarily cardiac
patients. Each unit frequently admitted both categories of patients when the
other unit was full. Patients receiving ventilatory support constituted 70%
of patients in the medical ICU and 60% of patients in the CCU.
We compared outcomes in the study unit before and after the intervention,
and between the study unit and a control unit during the same period after
the intervention. Using a random number generator, we selected 75 patients
from each of 3 groups: all patients admitted to the study unit during phase
1 and phase 2 and all patients admitted to the control unit during phase 2.
To detect whether unmeasured variables may have altered the rate of ADEs (secular
trend), we also randomly selected 50 patients from all those admitted to the
control unit during phase 1.
The intervention was the assignment of an experienced senior pharmacist
to make rounds with the patient care team in the study ICU. The pharmacist
made rounds with the residents, nurses, and attending staff each morning,
was present in the unit for consultation and assistance to the nursing staff
during the rest of the morning, and was available on call as necessary throughout
the day. The total commitment was approximately half of the pharmacist's time.
In the control ICU, as is the usual practice, another pharmacist was available
in the unit for part of the day but did not make rounds with physicians and
nurses. The intervention began in May 1994. Data collection began in October
1994 and continued through July 1995.
We assessed the effect of pharmacist participation with 2 measures:
(1) the change in the rate of preventable ADEs in the ordering stage and (2)
the number and acceptance of interventions recommended by the pharmacist.
We defined an ADE as an injury related to the use of a medication. A preventable
ADE is an injury caused by an error in the use of a medication (eg, hypotension
or hypoglycemia, changes in mental status, bleeding, or cardiac arrest).1
Using previously described methods,7
trained and experienced investigators (1 nurse and 1 pharmacist) identified
incidents (apparent medication errors or ADEs) by review of medical records
in which they examined all progress notes, orders, and laboratory results
during the index admission.
Incidents were evaluated independently by 2 physician reviewers (L.L.L.
and D.W.B.) who classified them according to whether or not an ADE or potential
ADE was present. Using pre-established criteria,7
they also made judgments of severity, preventability, and, if an error was
present, the type of error and the stage in the process at which the error
occurred. When there were disagreements the reviewers met and reached consensus.
If consensus could not be reached, a third reviewer evaluated the incident.
Reliability for these judgments has previously been reported7(for
judgments about whether an incident was an ADE, κ=0.81-0.98; for preventability, κ=0.92;
and for severity, κ=0.32-0.37). All reviewers and investigators were
blinded to patient group assignment.
To develop descriptive information about changes suggested by the pharmacist,
we measured the number of interventions, the type of intervention, and the
percentage of recommendations accepted. For this purpose, the pharmacist completed
a report form for each intervention that could potentially lead to a change
in orders, noting the date, drug, nature of the order, the specific recommendation,
and whether or not it was accepted by the physicians. The type of intervention
was then classified as shown in Table 1. The pharmacist also recorded events that did not involve order
changes, such as errors in the pharmacy system or identification of ADEs.
The primary measure used to assess the effect of the interventions was
the rate of preventable ADEs due to prescribing errors. We conducted comparisons
at 2 points in time in the study unit, before and after the intervention,
and between the study and control units after the intervention.
For the before-after evaluation, we compared the rate of occurrence
of preventable ordering ADEs among patients in the study unit during phase
1 with the rate in the same unit during phase 2. For the between-unit comparison,
we compared the rate in the study unit during phase 2 with the rate of occurrence
in the control unit in phase 2. To assess potential secular trends, we also
compared the rate in the control unit in phase 1 with its rate in phase 2.
Comparisons between rates in phases 1 and 2 in the study unit (before
and after) and between the study unit and the control unit in phase 2 (contemporaneous)
were made using unpaired t tests. Analyses were performed
using SAS statistical software.8
The overall rates, expressed as preventable ordering ADEs per 1000 patient-days,
are shown for both phases for both units in Table 2. In the before and after comparison, the rate of preventable
ordering ADEs per 1000 patient-days decreased in the study unit by 66% from
phase 1 to phase 2 (10.4 [95% CI, 7-14] to 3.5 [95% CI, 1-5]; P<.001).
When the intervention unit was compared with the control unit during
the same time period (phase 2), the rate of preventable ordering ADEs in the
study unit was 72% lower than in the control unit (3.5 [95% CI, 1-5] vs 12.4
[95% CI, 8-17] per 1000 patient-days; P<.001).
The preventable ordering ADE rate in the control unit rose slightly from phase
1 to phase 2 (10.9 [95% CI, 6-16] to 12.4 [95% CI, 8-17]), but this change
was not significant (P=.76).
When results were calculated in terms of number of patients (admissions),
the differences in rates were similar: in the study unit, the rate of preventable
ordering ADEs decreased by two thirds, from 12% in phase 1 to 4% in phase
2, while it was essentially unchanged in the control unit (10% to 11%).
The rate of all ADEs also decreased substantially in the study unit
from phase 1 to phase 2 (33.0 [95% CI, 27-39] to 11.6 [95% CI, 8-15]; P<.001). However, the rate rose in the control unit
by 34.3% (34.7 [95% CI, 26-43] to 46.6 [95% CI, 38-55; P<.001).
During phase 2, a total of 398 pharmacist interventions were recorded
(Table 1). Of these, 366 were
related to ordering, of which 362 (99%) were accepted by the physicians. Nearly
half (178/389 [46%]) were pharmacist-initiated clarification or correction
of a proposed or previous order. These errors included incomplete orders,
wrong dose, wrong frequency, inappropriate choice, and duplicate therapy.
Examples were a recommendation to reduce the dose of intravenous phenytoin
from 300 mg 3 times per day, the correct oral dose,
to 100 mg 3 times per day and reduction of the dose of ampicillin administered
to a patient with renal failure.
In 100 instances, the pharmacist provided drug use information, most
often at the time the decision was being made about whether to order a drug.
Examples were education of the house staff on the selection of sedatives in
patients receiving ventilatory support and the risk of extrapyramidal adverse
effects from excessive doses of droperidol.
The pharmacist recommended alternative therapy in 47 cases, suggesting
drugs that were safer or cheaper but equally effective, such as changing from
intravenous to oral metoclopromide. Potential problems relating to drug interactions
and drug allergies were identified by the pharmacist in 22 cases and use of
alternative drugs was recommended.
Thirty-two of the pharmacist interventions did not relate to ordering.
Among these, the pharmacist provided special order drugs or approved nonformulary
use of a drug in 14 instances, identified 6 previously unrecognized ADEs,
and uncovered 12 systems errors in the pharmacy dispensing system. One example
of dispensing errors was that a medication was prepared for peripheral intravenous
infusion when a smaller volume was required for central administration to
minimize fluid load.
In previous studies, we demonstrated that nearly half of preventable
ADEs resulted from errors in the prescribing process.1
Prescribing errors frequently have a cascade effect, causing errors downstream
in dispensing or administration. The major cause of prescribing errors was
physicians' lack of essential drug and patient information at the time of
One method of providing
such information is computerized physician order entry, which has been shown
to reduce the rate of serious medication errors by more than half.9 Evans et al10 have
demonstrated that a computer-assisted management program for antibiotics can
substantially reduce excessive use and misuse of antibiotics as well as reduce
length of hospital stay and costs. However, most hospitals do not yet have
computerized ordering by physicians, so incorporation of the pharmacist into
the patient care team is a more feasible alternative at present, especially
in units with high medication use.
We estimated the financial
impact of the 66% reduction in ADEs. The cost of an ADE has been estimated
at $2000 to $2500 per event in 1993.11,12
However, the cost of a preventable ADE, one due to an error, was estimated
at $4685.9 For the year 1995 , we estimate
that 58 ADEs were prevented. At $4685 each, the cost reduction in this single
unit would be approximately $270,000 per year. The intervention required no
additional resources and represented a different use of the existing pharmacist's
time. Rather than spending time checking and correcting orders after they
had been sent to the pharmacy, the pharmacist was involved at the time the
order was written. While participating in rounds as a member of the patient
care team, the pharmacist reduced ADEs both by preventing errors and by intercepting
them. He prevented errors by providing information about doses, interactions,
indications, and drug alternatives to physicians at the time of ordering.
He intercepted errors by immediately reviewing all orders and correcting deficiencies
before the orders were transmitted to the pharmacy. In addition, the pharmacist
prevented nursing medication errors by providing ready consultation to the
nursing staff and teaching drug safety.
Finally, the on-site pharmacist
took overall responsibility for medication safety, spotting unsafe conditions
and identifying needs for process improvement. For example, during the study
period the pharmacist identified 12 systems errors in pharmacy function and
6 ADEs that probably would not have otherwise been discovered.
The presence of the pharmacist on rounds was well accepted by physicians,
as evidenced by the fact that 99% of the recommendations were accepted. While
staff perceptions were not evaluated systematically, in our experience, nurses
also accepted this role easily, appreciating the reduction in extra work,
such as telephoning physicians to have orders corrected. The pharmacist in
this study had to overcome the traditional impression of the medical staff
that pharmacists may be primarily concerned with costs. This academic medical
ICU environment had the added challenge of dealing with a new group of house
staff, fellows, and attending physicians every few weeks. In ICUs where the
attending physicians are permanent and fellows are assigned for many months,
acceptance might be enhanced.
Our study has several limitations.
We studied only 1 ICU in 1 teaching hospital. Adverse drug events are more
common in teaching hospitals than in community hospitals13
and occur more frequently in ICUs,1 so these
findings are not generalizable to all types of units or all types of hospitals.
However, the magnitude of the impact of the pharmacist's presence was so great
that a substantial effect would probably be found in ICUs in other hospitals.
Second, our results do not represent the full extent of preventable ADEs,
since record review does not capture all events, nor does it capture most
potential ADEs, the "near misses," because they are seldom recorded in patient
charts. Third, physicians and nurses in this ICU function as a team and make
rounds together. Pharmacist participation would be more difficult to arrange
in units where multiple physicians make rounds at different times. Finally,
the success of the pharmacist intervention depends on interpersonal relationships.
Thus, the personality and cooperativeness of the pharmacist and the medical
staff are critical factors in making this system work, especially at the beginning.
Similar prevention of ADEs prompted by a designated ICU pharmacist probably
would be less likely to occur in ICUs in which staff are not part of a multidisciplinary
team and when ICU staff are not open to the important role that the pharmacist
can play in optimizing ICU management.
We conclude that participation
of a pharmacist on medical rounds can be a powerful means of reducing the
risk of ADEs.