Meta-Analysis: Methods for Diagnosing Intravascular Device–Related Bloodstream Infection

15 March 2005 | Volume 142 Issue 6 | Pages 451-466

Background: No consensus exists on the best methods for diagnosis of intravascular device (IVD)–related bloodstream infection.

Purpose: To identify the most accurate methods for diagnosis of IVD-related bloodstream infection.

Data Sources: 51 English-language studies published from 1966 to 31 July 2004.

Study Selection: Studies of diagnostic tests for IVD-related bloodstream infection that described a reference standard and provided sufficient data to calculate sensitivity and specificity.

Data Extraction: Study quality, diagnostic tests examined, patient characteristics, prevalence, sensitivity, and specificity.

Data Synthesis: Pooled sensitivity and specificity were calculated for 8 diagnostic methods. Summary measures of accuracy were Q* (the upper leftmost point on the summary receiver-operating characteristic curve) and mean D (a log odds ratio). Subgroup analyses were used to assess heterogeneity. Overall, the most accurate test was paired quantitative blood culture (Q* = 0.94 [95% CI, 0.88 to 1.0]), followed by IVD-drawn qualitative blood culture (Q* = 0.89 [CI, 0.79 to 0.99]) and the acridine orange leukocyte cytospin test (Q* = 0.89 [CI, 0.79 to 0.91]). The most accurate catheter segment culture test was quantitative culture (Q* = 0.87 [CI, 0.81 to 0.93]), followed by semi-quantitative culture (Q* = 0.84 [CI, 0.80 to 0.88]). Significant heterogeneity in pooled sensitivity and specificity was observed across all test categories.

Limitations: The limited number of studies of some of the diagnostic methods precludes precise estimates of accuracy.

Conclusions: Paired quantitative blood culture is the most accurate test for diagnosis of IVD-related bloodstream infection. However, most other methods studied showed acceptable sensitivity and specificity (both >0.75) and negative predictive value (>99%). The positive predictive value of all tests increased greatly with high pretest clinical probability. Catheters should not be cultured routinely but rather only if IVD-related bloodstream infection is suspected clinically.

Editors' Notes Context Several methods exist for diagnosing intravascular device–related bloodstream infection. Contribution This meta-analysis summarized data from 51 studies for 8 diagnostic methods. Paired quantitative cultures drawn concomitantly from a peripheral vein and the suspected catheter appeared most accurate, but several methods, including quantitative and semi-quantitative catheter segment cultures, acridine orange leukocyte cytospin tests, and quantitative blood cultures drawn through the catheter, had reasonable accuracy. Cautions Studies used different diagnostic reference standards. Some methods were evaluated in few studies. –The Editors

 

Author and Article Information

From University of Wisconsin Medical School, Madison, Wisconsin.

Presented in part at the 43rd Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, Illinois, 14–17 September 2003.

Grant Support: By an unrestricted gift for research from the Oscar Rennebohm Foundation of Madison, Wisconsin.

Potential Financial Conflicts of Interest: Grants received: D.G. Maki (Johnson & Johnson, Inc., and Becton Dickinson).

Requests for Single Reprints: Dennis G. Maki, MD, H5/574, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792; e-mail, dgmaki{at}facstaff.wisc.edu.

Current Author Addresses: Dr. Safdar: H4/572, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792.

Dr. Fine: K6/420, Clinical Sciences Center, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792.

Dr. Maki: H5/574, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792.