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. 2017 Oct 24;55(11):3258–3266. doi: 10.1128/JCM.00911-17

TABLE 1.

Performance of the BD Max xEBP by specimen origin

Organism and specimen type BD Max xEBP performance characteristic compared to the reference methodc,g
No. of specimens with result:
 PPA (95% CI) NPA (95% CI) Kappaf (95% CI)
True pos False neg False pos True neg Totalb
Vibrio
    Prospective fresh 0 0 1 837 838 No data 99.9 (99.3–100)
    Prospective frozen 2 0 6 1,380 1,388 100 (32.4–100) 99.6 (99.1–99.8)
    Retrospectivea 4 0 1 61 66 100 (51.0–100) 98.4 (91.4–99.7)
    Contrived 96 0 0 288 384 100 (95.2–100) 100 (98.4–100)
    Total 102 0 8 2,566 2,676 100 (96.4–100) 99.7 (99.4–99.8) 0.96 (0.93–0.99)
Plesiomonas shigelloides
    Prospective fresh 0 0 0 834 834 No data 100 (99.5–100)
    Prospective frozen 0 0 3 1,384 1,387 No data 99.8 (99.4–99.9)
    Retrospectivea 7 0 1 84 92 100 (64.6–100) 98.8 (93.6–99.8)
    Contrived 96 0 1d 287 384 100 (96.2–100) 99.7 (98.1–99.9)
    Total 103 0 5 2,589 2,697 100 (96.4–100) 99.8 (99.5–99.9) 0.98 (0.95–1)
Yersinia enterocolitica
    Prospective fresh 0 0 0 823 823 No data 100 (99.5–100)
    Prospective frozen 0 0 1 1,381 1,382 No data 99.9 (99.6–100)
    Retrospectivea 9 0 0 79 88 100 (70.1–100) 100 (95.4–100)
    Contrived 95 1e 0 287 384 99.0 (94.3–99.8) 99.7 (97.8–99.9)
    Total 104 1 1 2,570 2,676 99.0 (94.8–99.8) 99.96 (99.8–1) 0.99 (0.98–1)
ETEC
    Prospective fresh 9 0 0 821 830 100 (70.1–100) 100 (99.5–100)
    Prospective frozen 17 0 4 1,345 1,366 100 (81.6–100) 99.7 (99.2–99.9)
    Retrospectivea 14 1 1 54 70 93.3 (70.2–98.8) 98.2 (90.4–99.7)
    Total 40 1 5 2,220 2,266 97.6 (87.4–99.6) 99.8 (99.5–99.9) 0.93 (0.87–0.99)
a

Results of all retrospective samples were confirmed by alternate PCR and bidirectional sequencing prior to testing with the BD Max xEBP.

b

Number of specimens varies by target due to differences in compliance with study protocol and unresolved results.

c

Abbreviations: pos, positive; neg, negative; PPA, positive percent agreement; NPA, negative percent agreement; CI, confidence interval.

d

One false-positive result occurred initially for P. shigelloides from an unpreserved specimen at 4 times the LoD but was found negative upon repeat testing from the SBT.

e

One false-negative result was observed for Y. enterocolitica among a Cary-Blair-preserved specimen at 4 times the LoD but was positive upon repeat testing from the SBT.

f

Kappa coefficient, correlation of BD Max result with reference methods.

g

Reference methods were standard culture techniques and/or alternate PCR followed by sequencing.