Doelmatigheid en kosten-effectiviteit van sneldiagnostiek voor dragerschap van methicilline-resistente Staphylococcus aureus (MRSA). (Health care efficciency and cost-efficacy of rapid diagnostic testing of methicillin-resistant Staphylococcus aureus)

. objective(s) / research question(s): Prevalence of MRSA infections has remained extremely low in Dutch health care settings due to a nationally implemented Search & Destroy (S&D) policy (1). Cornerstone of S&D is to actively trace potential carriers of MRSA through surveillance; to treat suspected or identified carriers, while hospitalized, in strict isolation; to screen all contact patients and health care workers in case of an unexpected finding of MRSA-colonization; to close a ward for new admission when a subsequent unexpected MRSA-carrier is found; and to only reopen the ward when remaining patients (and health care workers) are prove MRSA free by screening (2). Screening is based upon classical laboratory culture results, which carry an unavoidable delay of >3 days to exclude carriership. On average the delay is 5 days (3) Yet, ±95% of all patients suspected of MRSA-colonization eventually appear not to be colonized. For a large Dutch hospital (UMC Utrecht, 900 beds) this implicated strict isolation of 145 patients for a total of 552 days, in 2004. Projected to The Netherlands, the policy affects ±7500 patients with 30.000 isolationdays per year (assuming a mean of 500 beds for 100 hopspitals). Though succesful, the S&D policy has several disadvantages: Necessary measures are costly (estimated 270kE/year in the UMC Utrecht (4))and they decrease quality of care and patient satisfaction (5). Most importantly, though, is that patient care in single rooms with barrier precautions increases the work load for nurses, which reduces admission capacity. Moreover, a formal cost-effectiveness analysis of S&D has never been performed (6). With yearly increasing numbers of patients suspected of MRSA-colonization, the S&D policy puts more and more constraints on our health care system. It is now possible, with a recently developed MRSA-specific PCR-technique (7), to determine carriership within a few hours. In this proposal we will determine the costs and efficacy of rapid testing of MRSA-carriership by means of PCR added to the currently practiced S&D policy. . study design: Multicenter, experimental study using historical controles (before-after study). . study population(s)/ datasets: All patients admitted to any of the participating hospitals that fullfill the current criteria for screening of MRSA-carriership. . intervention: In addition to the standard set of microbiological cultures, MRSA-PCR will be performed upon nasal swabs (and other relevant material if indicated) and will be analyzed immediately (<24 hours). Infection prevention measures will be based upon immediate PCR-results. Thus, strict isolation treatment will be abandoned when MRSA-PCR results are negative for MRSA. . outcome measures: Number of days of patient isolation and all costs associated with S&D policy. Prior to the intervention, daily costs of strict patient isolation will be determined. In addition, quality of life and patient satisfaction will be determined. . power/data analysis: Based on the current mean number of isolation days of 6 ±4 (MRSA-carriers are included in this number) 84 patients per study group are needed to demonstrate a reduction to an average of 4 patient days (alfa=0.05, beta=0.1). . economic evaluation: Initially, a simple cost-minimisation analysis will be performed, using all relevant data. The analysis will focus on isolation days, labortory tests and associated costs of personel. Material and laboratory costs are relatively simple to determine. Daily costs of treatment in isolation, however, are unknown and will be determined prospectively, prior to the intervention. Costs associated with an outbreak will have to be taken into account. In a decision model the likelihood of an MRSA-outbreak in case of false-negative PCR-results will be incorporated (based on retrospectively and prospectively collected data) and the associated costs for control will be predicted. Both for the setting when PCR-results are added to culture results, as well as for the hypothetical situation that only PCR-reulst are obtained. . time schedule: 1-6 months: preparation intervention and determining daily isolation costs 7-19 months: intervention 19-24 months: analysis