Meta Analysis
 Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection: A meta-analysis
This review may be edited
Summary
Posted By: Sharon McKinley
E-Mail: sharon.mckinley@uts.edu.au
Posted Date: 9 May 2001
Title: Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection: A meta-analysis
Authors: Veenstra DL. Saint S. Saha S. Lumley T. Sullivan SD.
Reference: JAMA. 281(3):261-7, 1999
Link: Click here for a direct link to the paper. A password may be required for access to fulltext.
Abstract: Context: Central venous catheters impregnated with chlorhexidine and silver sulfadiazine have recently been introduced for the prevention of catheter-related infections. However, there remains some uncertainty regarding the efficacy of these catheters because of conflicting reports in the literature.
Objective: To evaluate the efficacy of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in the prevention of catheter-related bloodstream infection.
Data Sources: Studies identified from a computerized search of the MEDLINE database from January 1966 to January 1998, reference lists of identified articles, and queries of principal investigators and the catheter manufacturer.
Study Selection: Randomized trials comparing chlorhexidine-silver sulfadiazine-impregnated central venous catheters with nonimpregnated catheters were included. The outcomes assessed were catheter colonization and catheter-related bloodstream infection confirmed by catheter culture.
Data Extraction: Twelve studies met the inclusion criteria for catheter colonization and included a total of 2611 catheters. Eleven studies with a total of 2603 catheters met the inclusion criteria for catheter-related bloodstream infection. Most patients in these studies were from groups considered to be at high risk for catheter-related infections. Summary statistics were calculated using Mantel-Haenszel methods under a fixed-effects model.
Data Synthesis: The summary odds ratio for catheter colonization was 0.44 (95% confidence interval [CI], 0.36-0.54; P<.001), indicating a significant decrease in catheter colonization associated with impregnated catheters. The studies examining the outcome of primary interest, catheter-related bloodstream infection, had a summary odds ratio of 0.56 (95% CI, 0.37-0.84; P=.005).
Conclusions: Central venous catheters impregnated with a combination of chlorhexidine and silver sulfadiazine appear to be effective in reducing the incidence of both catheter colonization and catheter-related bloodstream infection in patients at high risk for catheter-related infections.
 
Are the Results Valid?
1. Did the overview address a focused clinical question?
Yes. Efficacy of chlorhexidine and silver sulphardiazine impregnated catheters (AICs) in preventing central venous catheter (CVC) colonization and catheter-related blood stream infection (CR-BSI).
2. Were the criteria used to select articles for inclusion appropriate?

Mostly. Randomized controlled trials (RCTs) of AICs vs nonimpregnated catheters (NICs)

- that had sufficient data to calculate the size of the effect of AICs in reducing colonization and CR-BSI compared to NICs (effect size - ES)

- in which the author subsequently gave required information that was not included in the original report

- in which quasi-randomisation was used (e.g. by last digit of medical record number)
3. Is it unlikely that important, relevant studies were missed?
Yes. But four studies published only as abstracts have been included ? with additional information provided by their authors. When unpublished data is presented, it may be even more important to undertake an explict validity appraisal.
4. Was the validity of the included studies appraised?
This is not explicitly stated and appears to be questionable. Three studies with quasi-randomisation were included, as were two with the patient numbers (as distinct from catheter numbers) not reported. It is reported that patient eligibility and study dropouts were adequately described in only seven of the 12 and 11 studies in the analyses of the two outcomes. Even in those the reader does not know if all the patients were accounted for at the conclusion of the studies. Care was taken to include only studies with like and acceptable definitions of the two outcome measures.
5. Were assessments of studies reproducible?
Yes. Abstracting was done independently by two authors, one of whom was blinded to publication details etc, and the third author resolved any discrepancies.
6. Were the results similar from study to study?
Not for the colonization outcome. This is somewhat evident from the Peto chart, and the test for heterogeneity is significant, even after the study that contributed most to the heterogeneity was taken out. For CR-BSI the effects are all in the same direction and not greatly scattered on the Peto chart, and the p value in the test for heterogeneity was high (0.81), suggesting heterogeneity was unlikely.
What are the Results?
1. What are the overall results of the overview?

Patients who had AICs had less risk of catheter colonization (0.44) and less bloodstream infection (0.56) than those who had the standard catheter. The significance of these findings persisted even when studies with important design flaws were controlled for in the analyses (more than one catheter per patient) or removed from the analyses (quasi-randomization), and when studies that used only triple lumen catheters were analysed. For CR-BSI (if my calculations are right):


OR = 0.59 (?? as diff from article)
RR = 0.59
RR reduction = 0.41
ARR = .021
NNT = 48
2. How precise were the results?
The 95% confidence intervals are 0.36-0.54 for colonization and 0.37-0.84 for CR-BSI.
Will the Results Help Me In Caring For My Patients?
1. Can the results be applied to my patient care
Possibly. Four of the studies in the CR-BSI analysis were in ICU patients and used mainly triple-lumen catheters. We mostly do not know what sort of ICU patients they were--diagnoses, severity of illness etc. The questionable validity of some of included studies is cause for reservation.
2. Were all clinically important outcomes considered?
No--only colonization of catheter and bloodstream infection. However the same group have published an analysis of the effects of AICs on death and costs in: Veenstra DL. Saint S. Sullivan SD. Cost-effectiveness of antiseptic-impregnated central venous catheters for the prevention of catheter-related bloodstream infection. JAMA. 282(6):554-60, 1999 Aug 11.
3. Are the benefits worth the harms and costs?
If my calculations are in the right ballpark, use of the AIC in about 50 patients would prevent one CVC-related bloodstream infection. There were no adverse effects reported from the use of the intervention catheter, and the risk of other CVC-related adverse events should not have changed. So risk of additional harm appears to be minimal. We cannot determine the benefits-costs question from this article. The authors argue that 3-7% of CVCs in ICU patients lead to CR-BSI, and that this has an attributable mortality of 10-35% and associated costs of US$30,000 per episode in the US system. On that basis one could argue that the benefits are worth the costs of the catheters, but we should look at their costs and mortality analysis and do the calculations based on our own CR-BSI incidence and costs data.

What other people had to say about:
Efficacy of antiseptic-impregnated central venous catheters in preventing catheter-related bloodstream infection: A meta-analysis

Add Your Comment
[ Back ]

Any questions or comments please contact Gordon S. Doig
Implemented and designed by John Soer and Gordon Doig
Page last modified on Friday August 10, 2001
www.EvidenceBased.net
  THIS IS A SPACE MESSAGE. THIS IS STILL THE BEST METHOD TO SPACE A TABLE FOR NETSCAPE AND INTERNET EXPLORER. IF YOU SEE THIS MESSAGE CONTACT WEBADMIN@EvidenceBased.net