To address this question, Bates and colleagues developed a CER study that compared the effectiveness of CPOE alone with CPOE plus a team intervention. The study, conducted within six units at Brigham and Women’s Hospital in Boston, Mass., used a pre/post design that compared rates of medication errors prior to CPOE adoption with the error rate during the ten months following CPOE adoption. Data were collected in the pre-CPOE period in six units of the hospital; the same six units were used in the post-CPOE period, along with two additional units included to increase study power.
While most CER studies of medications or devices have compared these items to one another, this study compared two quality improvement interventions (CPOE and CPOE plus a team-based intervention). In the CPOE intervention, physicians could select from a menu of medications defined by the hospital formulary, with default dose and dose ranges provided for each, as well as automatic checking for common drug allergies and drug-drug interactions. The CPOE application was developed in-house and was embedded in the existing hospital information system. The team intervention centered on pharmacy-specific process changes, including changing the role of the pharmacist, standardizing labeling of intravenous bags, and implementing a pharmacy communication log so that the nursing staff could better communicate with the pharmacy staff.
The primary study outcome was the rate of unintercepted serious medication errors (preventable and unintercepted potential adverse drug events [ADEs]). Secondary study outcomes included the numbers of errors in each stage (ordering, transcription, administration, and dispensing of drugs) and also within specific categories targeted by the interventions (wrong dose, errors in concentration of intravenous solutions, etc.). Case finding was accomplished by reporting of incidents by nurses and pharmacists, solicitation of incidents by a study investigator interacting with staff, and patient chart reviews by a study investigator.