TABLE 3.

Concordance between MALDI-TOF MS and standard identification methods^a

Match category	Result (% concordance [95% confidence interval])
	16S	Phoenix	Traditional phenotypic methods	Overall
Speciesb	263/269 (97.8% [95.2–99.2])	160/167 (95.8% [91.6–98.3])	99/101 (98.0% [93.0–99.8])	522/537 (97.2% [95.4–98.4])
Genusc	282/282 (100% [98.7–100])	166/167 (99.4% [96.6–100])	103/103 (100% [96.5–100])	551/552 (99.8% [99.0–100])
No reliable identificationd	13/16 (81.3% [54.4–96])	0/0	0/0	13/16 (81.3% [54.4–96])
Total	298	167	103	568

^aThe standard identification method had a significant effect on distribution across match categories (P = 0.0008, Fisher's exact test).

^bNumber of isolates concordant to species level with standard method identification/total number of isolates scoring ≥1.9.

^cNumber of isolates concordant to genus level with standard method identification/total number of isolates scoring ≥1.7. Isolates scoring <1.7 were considered unreliable for identification by MALDI regardless of their concordance with standard method identification.

^dNumber of isolates concordant to genus level with standard method identification/total number of isolates scoring <1.7. Isolates scoring <1.7 were considered unreliable for identification by MALDI regardless of their concordance with standard method identification.