2.50
Hdl Handle:
http://hdl.handle.net/10755/160210
Type:
Presentation
Title:
Diagnostic Validity of Semi-Quantitative Swab Cultures
Abstract:
Diagnostic Validity of Semi-Quantitative Swab Cultures
Conference Sponsor:Midwest Nursing Research Society
Conference Year:2007
Author:Gardner, Sue, PhD, RN
P.I. Institution Name:The University of Iowa
Contact Address:College of Nursing, 320 NB, Iowa City, IA, 52242, USA
Co-Authors:R.A. Frantz and H. Park, College of Nursing, The University of Iowa, Iowa City, IA; S. Gardner, S.L. Hillis, and M. Scherubel, Center for Research in the Implementation of Innovative Strategies in Practice (CRIISP), Iowa City VA Medical Center, Iowa City
Swab cultures of wounds are noninvasive and most laboratories are capable of semi-quantitatively processing these specimens. The purpose of this study was to examine the diagnostic validity of semi-quantitative swab cultures obtained using Levine's technique and to compare semi-quantitative and quantitative swab cultures. Two swab specimens were obtained from a sample of chronic wounds using Levine's technique. One was processed using quantitative laboratory procedures and the other using semi-quantitative laboratory procedures. The diagnostic validity of the findings from each swab culture process was determined by associating the culture findings of each with quantitative tissue cultures (reference standard). A receiver operating characteristic (ROC) curve was used to evaluate the accuracy of both the quantitative and semi-quantitative swab cultures. The area under the ROC curve (AUC) provides a summary measure of accuracy. Recovery of specific organisms was compared between the tissue and swab specimens to evaluate concordance. Forty-four subjects participated in the study. The AUC of the semi-quantitative swab culture was not significantly higher than the diagonal chance line of .50 suggesting a non-informative test. The AUC for quantitative swab cultures was .821. The AUC of the quantitative swab culture was significantly higher than the diagonal chance line of 0.5. In addition, it was significantly higher than the AUC of the semi-quantitative swab culture (p = 0.0128). The mean concordance of semi-quantitative cultures in recovering all organisms was only 57%. The mean concordance of quantitative swab cultures in recovering all organisms was 72%, substantially higher than the mean concordance of semi-quantitative swabs. The findings of this study suggest that swab specimens processed using semi-quantitative processes do not provide culture findings that correlate well with culture findings from tissue specimens. The implication of this finding is that semi-quantitative swab cultures may provide meaningless information from which to guide wound care decisions. More meaningful information can be obtained from swab specimens if they are quantitatively processed in the laboratory.
Repository Posting Date:
26-Oct-2011
Date of Publication:
17-Oct-2011
Sponsors:
Midwest Nursing Research Society

Full metadata record

DC FieldValue Language
dc.typePresentationen_GB
dc.titleDiagnostic Validity of Semi-Quantitative Swab Culturesen_GB
dc.identifier.urihttp://hdl.handle.net/10755/160210-
dc.description.abstract<table><tr><td colspan="2" class="item-title">Diagnostic Validity of Semi-Quantitative Swab Cultures</td></tr><tr class="item-sponsor"><td class="label">Conference Sponsor:</td><td class="value">Midwest Nursing Research Society</td></tr><tr class="item-year"><td class="label">Conference Year:</td><td class="value">2007</td></tr><tr class="item-author"><td class="label">Author:</td><td class="value">Gardner, Sue, PhD, RN</td></tr><tr class="item-institute"><td class="label">P.I. Institution Name:</td><td class="value">The University of Iowa</td></tr><tr class="item-address"><td class="label">Contact Address:</td><td class="value">College of Nursing, 320 NB, Iowa City, IA, 52242, USA</td></tr><tr class="item-email"><td class="label">Email:</td><td class="value">sue-gardner@uiowa.edu</td></tr><tr class="item-co-authors"><td class="label">Co-Authors:</td><td class="value">R.A. Frantz and H. Park, College of Nursing, The University of Iowa, Iowa City, IA; S. Gardner, S.L. Hillis, and M. Scherubel, Center for Research in the Implementation of Innovative Strategies in Practice (CRIISP), Iowa City VA Medical Center, Iowa City</td></tr><tr><td colspan="2" class="item-abstract">Swab cultures of wounds are noninvasive and most laboratories are capable of semi-quantitatively processing these specimens. The purpose of this study was to examine the diagnostic validity of semi-quantitative swab cultures obtained using Levine's technique and to compare semi-quantitative and quantitative swab cultures. Two swab specimens were obtained from a sample of chronic wounds using Levine's technique. One was processed using quantitative laboratory procedures and the other using semi-quantitative laboratory procedures. The diagnostic validity of the findings from each swab culture process was determined by associating the culture findings of each with quantitative tissue cultures (reference standard). A receiver operating characteristic (ROC) curve was used to evaluate the accuracy of both the quantitative and semi-quantitative swab cultures. The area under the ROC curve (AUC) provides a summary measure of accuracy. Recovery of specific organisms was compared between the tissue and swab specimens to evaluate concordance. Forty-four subjects participated in the study. The AUC of the semi-quantitative swab culture was not significantly higher than the diagonal chance line of .50 suggesting a non-informative test. The AUC for quantitative swab cultures was .821. The AUC of the quantitative swab culture was significantly higher than the diagonal chance line of 0.5. In addition, it was significantly higher than the AUC of the semi-quantitative swab culture (p = 0.0128). The mean concordance of semi-quantitative cultures in recovering all organisms was only 57%. The mean concordance of quantitative swab cultures in recovering all organisms was 72%, substantially higher than the mean concordance of semi-quantitative swabs. The findings of this study suggest that swab specimens processed using semi-quantitative processes do not provide culture findings that correlate well with culture findings from tissue specimens. The implication of this finding is that semi-quantitative swab cultures may provide meaningless information from which to guide wound care decisions. More meaningful information can be obtained from swab specimens if they are quantitatively processed in the laboratory.</td></tr></table>en_GB
dc.date.available2011-10-26T22:43:44Z-
dc.date.issued2011-10-17en_GB
dc.date.accessioned2011-10-26T22:43:44Z-
dc.description.sponsorshipMidwest Nursing Research Societyen_GB
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