Analytical approach:
The analysis was based on a decision tree model populated with data derived from a single study. A short-term horizon was considered. The perspective was that of the intensive care unit.
Effectiveness data:
Clinical data were taken from the Dressing Study, a prospective randomised controlled trial that was carried out in seven intensive care units (two medical, two surgical and three medical-surgical units) in three university and two general hospitals in France. This study compared seven- or three-day CHGIS versus seven- or three-day standard dressing. In total 1,636 patients were enrolled and followed until intensive care unit discharge. The risk of major catheter-related infections (MCRIs) was the key input of the model. Bootstrapping was used to estimate confidence intervals (CIs) around expected MCRI rates.
Monetary benefit and utility valuations:
Not considered.
Measure of benefit:
No summary benefit measure was used. Rate of MCRI was the primary outcome.
Cost data:
The economic analysis was carried out alongside the clinical trial using a micro-costing approach that included the main cost categories: dressing (time per dressing, number of nurses and materials), treatment of contact dermatitis caused by CHGIS, diagnosis of catheter colonisation, treatment of MCRIs and additional length of stay. Resource quantities were taken directly from the Dressing Study. Unit costs were taken from selected participating hospitals. Costs were estimated in Euros then converted to and expressed in USA dollars ($). The price year was 2007.
Analysis of uncertainty:
One- and two-way sensitivity analyses were carried out to identify parameters that effected total costs such as MCRI rate, cost of MCRI and prevention effect of the CHGIS dressing.