Reducing vancomycin use utilizing a computer guideline: results of a randomized controlled trial

Abstract

Background: Vancomycin-resistant enterococci represent an increasingly important cause of nosocomial infections. Minimizing vancomycin use represents a key strategy in preventing the spread of these infections.

Objective: To determine whether a structured ordering intervention using computerized physician order entry that requires use of a guideline could reduce intravenous vancomycin use.

Design: Randomized controlled trial assessing frequency and duration of vancomycin therapy by physicians.

Participants and setting: Three hundred ninety-six physicians and 1,798 patients in a tertiary-care teaching hospital.

Intervention: Computer screen displaying, at the time of physician order entry, an adaptation of the Centers for Disease Control and Prevention guidelines for appropriate vancomycin use.

Main outcome measures: The frequency of initiation and renewal of vancomycin therapy as well the duration of therapy prescribed on a per prescriber basis.

Results: Compared with the control group, intervention physicians wrote 32 percent fewer orders (11.3 versus 16.7 orders per physician; P = 0.04) and had 28 percent fewer patients for whom they either initiated or renewed an order for vancomycin (7.4 versus 10.3 orders per physician; P = 0.02). In addition, the duration of vancomycin therapy attributable to physicians in the intervention group was 36 percent lower than the duration of therapy prescribed by control physicians (26.5 versus 41.2 days; P = 0.05). Analysis of pharmacy data confirmed a decrease in the overall hospital use of intravenous vancomycin during the study period.

Conclusion: Implementation of a computerized guideline using physician order entry decreased vancomycin use. Computerized guidelines represent a promising tool for changing prescribing practices.

Figure 1

The intervention screen for initial vancomycin orders as it appeared to physicians in the intervention group during the study period.

Figure 2

The computer screen for renewal of vancomycin orders as it appeared to physicians in the intervention group of the study.

Figure 3

The variation in the monthly percentage of patients in the hospital on vancomycin. The values on the vertical axis were obtained by dividing the number of patients on vancomycin each month by the number of patients in the hospital that month and multiplying by 100 to yield percentages. The vertical line between the months of May and July on the horizontal axis marks the beginning of the study period. Piecewise linear regression revealed that both the slope and vertical intercept changed significantly (P = 0.04 and P = 0.01, respectively) after the intervention.

Figure 4

The amount of vancomycin dispensed per month. The values on the vertical axis were obtained by dividing the number of grams of vancomycin dispensed each month by the number of hospitalized patients that month. The horizontal axis shows the calendar months. Again, the vertical line between May and July corresponds to the beginning of the study period. While the amount of vancomycin dispensed each month can be seen to decrease steadily over time, this decrease was not significantly affected by the intervention.