Measuring the clinical value and impact of C.difficile POC testing in ICU and Geriatric wards

Most hospitals detect Clostridium difficile using ELISA tests; these have been recently demonstrated (WILCOX 2009) to miss up to 30% of truly infected patients, and also have a significant false-positive rate. More accurate methods such as Cytotoxin Neutralization Assay or Toxigenic culture require at least 48-72 hours to produce a result, which means a significant delay in achieving a definite diagnosis.
These weaknesses of current approaches can result in an increased risk of disease transmission, inappropriate use of antibiotics and isolation facilities, unnecessary cohorting and increase in disease severity due to the delay in taking appropriate action.
There is an urgent need for a new diagnostic algorithm, based on rapid AND accurate results.
In this study we propose to utilise the Xpert C.difficile assay in elderly care wards and ITU. We will measure the effect of real-time CDI results disease severity and other patient outcomes as well as impact on use of other hospital resources, e.g. further diagnostic testing.
The assay Xpert C.difficile provides state-of-the art golden standard sensitivity and specificity with PCR technology, exceeding the performance of most currently used tests (as demonstrated in several recent publications (Wilcox, Novak-Weekley). The assay is run on the robust GeneXpert platform, which is the only platform to date providing completely integrated sample processing and quality controls on board with test results in less than 50 minutes. The GeneXpert platform is modular and the instruments can easily be connected to Hospital and Laboratory information systems. The Xpert C.difficile test can provide users consistently with results in less than 1 hour, including a presumptive identification of the epidemic 027 strain, which enables usage 24/7 by any health care personnel.
To date no data on the benefit of real-time availability of diagnostic results for CDI exclusion or confirmation and its impact on patient management in a point-of-care setting have been published.
The objective of this study is to measure patient and overall hospital operational benefits as well as providing unique insight into disease acquisition mechanisms. The study is designed to measure the time from sample collection to result, ease of use and acceptability, patient length-of-stay and disease acquisition type (endogenous vs. transmission). The study period will necessitate 18 months of patient recruitment in order to be statistically significant.
The outcome of this study will provide valuable evidence for hospital finance managers, infection control teams, medical directors and pathology services when making decisions about the delivery of patient care. Cost-effectiveness data for patients with hospital-acquired diarrhoea in the key areas of intensive and elderly care will also be provided.