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11
Performance characteristics.
Clinical Performance
The performance characteristics of the DiagCORE Respiratory Panel 2 assay were assessed in a
multicenter clinical trial. Both the performance of the universal transport medium of
nasopharyngeal swab specimen (´UTM´), and of a dry nasopharyngeal swab specimen
(FLOQSwabs, Copan ref 503CS01) (´SWAB´) were assessed. In the latter case, a swab is directly
entered in the DiagCORE cartridge after collection avoiding the transfer into a liquid medium. This
testing approach may greatly support safe and error-free sample managment, especially at the
point of care settting.
The study was designed as observational, prospective-retrospective, using left-over samples
obtained from subjects with signs and symptoms of an acute respiratory infection. Participating
sites were asked to test fresh and/or frozen clinical samples, according to a
protocol and
site/specific instructions.
Three (3) hospital laboratories, located in Copenhagen (Denmark), Bonn, (Germany) and Paris,
(France) participated in the study. Samples tested by the DiagCORE Respiratory Panel 2 were
compared with the results of the standard of care (SOC) method(s) at the sites, as wells as with a
range of validated and commercially available molecular methods. This approach provided
results for pathogens not detected by SOC and/or allowed for final discrepancy resolution of
discordant results. As such the DiagCORE Respiratory Panel 2 assay results were compared against
Filmarray Respiratory Panel 1.7 & 2 and the Allplex Respiratory Panel assay.
A total of 578 clinical UTM patient samples were enrolled into the study. One (1) sample was
excluded from the analysis due to the sample being misplaced between DiagCORE and
comparator testing. Seven (7) of 577 samples failed initial testing, resulting in a first testing success
rate of 98.8%. The failure rate includes the failure rate of the internal control, which was 0.17%
(1/577). Two (2) samples could not be retested due to insufficient remaining specimen volume. The
sample that showed an initial internal control failure was successful upon retesting.
Fifteen (15) pathogen results could not be resolved because there was no SOC result (10 results) or
no resolution method result available (5 results). This resulted in the loss of 2 samples, the remaining
unresolvable results were in samples with multiple pathogens detected (coinfection samples).
Clinical sensitivity or Positive Percent Agreement (PPA) was calculated as 100% x (TP / TP + FN). True
positive (TP) indicates that both the DiagCORE Respiratory Panel 2 and comparator(s) methods
had a positive result for the organism, and false negative (FN) indicates that the DiagCORE
Respiratory Panel 2 result was negative while the comparator resolution methods results were
positive. Specificity or Negative Percent Agreement (NPA) was calculated as 100% x (TN / TN + FP).
True negative (TN) indicates that both the DiagCORE Respiratory Panel 2 and the comparator
method had negative results, and a false positive (FP) indicates that the DiagCORE Respiratory
Panel 2 result was positive but the comparator methods results were negative. For the calculation
of the clincial specificity of the individual pathogens the total available results were used, with the
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DiagCORE Respiratory Panel 2 Instructions for Use
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