The Impact of an Infectious Diseases Specialist-Directed Computerized Physician Order Entry Antimicrobial Stewardship Program Targeting Linezolid Use

Abstract

To the Editor—The utilization of various antimicrobial stewardship program (ASP) strategies such as prior authorization, prescriber feedback and education, and antibiotic order forms have demonstrated favorable impacts on antibiotic utilization in academic settings.1-4 To facilitate the implementation of ASPs, institutions have designed computer systems allowing physician/provider order entry (CPOE). CPOE allows direct entry of medical orders by authorized healthcare providers; this has the benefit of reducing errors by minimizing the ambiguity of handwritten orders, with greater benefits seen with the combination of CPOE and clinical decision support tools.5 In order to assess the potential impact of physician intervention on our community hospital–based, pharmacy-directed ASP, we undertook a prospective evaluation of linezolid use following the addition of an infectious diseases (ID) physician to the program. The subsequent addition of a customized CPOE-ASP order entry template incorporating a linezolid decision algorithm provided an opportunity to monitor its potential additional impact over the subsequent 16 months. In our 214-bed suburban nonacademic hospital, linezolid use was measured during a 32-month period from January 2008 to September 2010. The utilization formula combined a standardized defined daily dose (DDD) of 1,200 mg as recommended by the World Health Organization with hospital pharmacy purchasing data and hospital patient-days (PTD) to calculate a monthly DDD per 1,000 PTD. Prior to implementation of the CPOE-ASP, a primary intervention consisting of ID physician educational activities represented the only new intervention that had the potential for impacting linezolid use. Shortly prior to implementation of the CPOE system, linezolid usage guidelines based on Food and Drug Administration–approved indications6 along with additional evidence-based recommendations approved by a local committee of clinical pharmacists and ID specialists were developed specifically for our CPOE system. Recommendations regarding alternative antibiotics with their dosages and rationale for use as well as hyperlinked references were included in the order entry form. All providers ordering antibiotics were identified and educated on the CPOE system and the antibiotic guidelines. In addition, a linezolid utilization audit was performed over two 5-month periods during the preintervention and CPOE-ASP periods by clinical pharmacists to determine whether linezolid orders reflected institution-approved indications. The pharmacy provided information on the direct cost of linezolid during the periods studied. Baseline linezolid use over the 7 months prior to ID physician leadership involvement in the hospital’s ASP averaged 44 DDD/1,000 PTD (Figure 1). Following ID physician involvement in the program and education of the medical staff, over a 9-month period linezolid use fell to 28 DDD/1,000 PTD (, Student t test). A further decrease to a mean of 7 DDD/1,000 PTD was realized and sustained over a subsequent 16-month period following CPOE implementation in the setting of ongoing physician involvement ( from baseline, Student t test). Examination of the proportion of nonappropriate linezolid use by the pharmacist-based audit confirmed a significant decrease in linezolid orders that deviated from institutional guidelines from 77% (26 of 34 orders) to 11% (1 of 13 orders; , Fisher exact test).