Cost-effectiveness of an electronic medication ordering system (CPOE/CDSS) in hospitalized patients.

INTRODUCTION: Prescribing medication is an important aspect of almost all in-hospital treatment regimes. Besides their obviously beneficial effects, medicines can also cause adverse drug events (ADE), which increase morbidity, mortality and health care costs. Partially, these ADEs arise from medication errors, e.g. at the prescribing stage. ADEs caused by medication errors are preventable ADEs. Until now, medication ordering was primarily a paper-based process and consequently, it was error prone. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) is considered to enhance patient safety. Limited information is available on the balance between the health gains and the costs that need to be invested in order to achieve these positive effects. Aim of this study was to study the balance between the effects and costs of CPOE/CDSS compared to the traditional paper-based medication ordering. METHODS: The economic evaluation was performed alongside a clinical study (interrupted time series design) on the effectiveness of CPOE/CDSS, including a cost minimization and a cost-effectiveness analysis. Data collection took place between 2005 and 2008. Analyses were performed from a hospital perspective. The study was performed in a general teaching hospital and a University Medical Centre on general internal medicine, gastroenterology and geriatric wards. Computerized Physician Order Entry, combined with basic Clinical Decision Support System (CPOE/CDSS) was compared to a traditional paper based system. All costs of both medication ordering systems are based on resources used and time invested. Prices were expressed in Euros (price level 2009). Effectiveness outcomes were medication errors and preventable adverse drug events. RESULTS: During the paper-based prescribing period 592 patients were included, and during the CPOE/CDSS period 603. Total costs of the paper-based system and CPOE/CDSS amounted to €12.37 and €14.91 per patient/day respectively. The Incremental Cost-Effectiveness Ratio (ICER) for medication errors was 3.54 and for preventable adverse drug events 322.70, indicating the extra amount (€) that has to be invested in order to prevent one medication error or one pADE. CONCLUSIONS: CPOE with basic CDSS contributes to a decreased risk of preventable harm. Overall, the extra costs of CPOE/CDSS needed to prevent one ME or one pADE seem to be acceptable.

Medication errors: the impact of prescribing and transcribing errors on preventable harm in hospitalised patients.

BACKGROUND: Medication errors (MEs) affect patient safety to a significant extent. Because these errors can lead to preventable adverse drug events (pADEs), it is important to know what type of ME is the most prevalent cause of these pADEs. This study determined the impact of the various types of prescribing (administrative, dosing and therapeutic) and transcribing errors on pADEs in hospitalised patients. METHODS: During a 5-month period, data for patients admitted to a total of five internal medicine wards of one university and one teaching hospital in The Netherlands were prospectively collected by chart review. In each hospital, MEs were detected and classified by the same pharmacist, using the classification scheme for MEs developed by The Netherlands Association of Hospital Pharmacists. The primary outcome measure was the prevalence of pADEs during hospital stay. In consensus meetings, five pharmacists assessed the causal relationship between MEs and pADEs. The association between type of ME and pADEs was determined by a multivariate regression analysis taking into account potential confounders. RESULTS: The study included 592 hospital admissions with 7286 medication orders (MOs), of which 60% contained at least one prescribing or transcribing error. 1.4% of all MOs led to pADEs, concerning 14.8% of all admitted patients. The total number of pADEs was 103, and in 92 of these cases patients experienced temporary harm, in eight cases hospital admission was prolongued, two cases were life-threatening, and one was fatal. Therapeutic errors were most strongly associated with pADEs (OR 1.98; 95% CI 1.53 to 2.56). CONCLUSIONS: Although many prescribing and transcribing errors occur in the process of medication use of hospitalised patients, a minority lead to pADEs. In particular, therapeutic errors are the cause of these pADEs and are therefore clinically relevant. Intervention and prevention programmes should primarily focus on this type of medication error.