Table 2. Results by Laboratory and agreement relative to CDC expected results.

Laboratory	Missing	Inconclusive	a	b	c	d	Sensitivity	Specificity	Concordance	Kappa
L01	0	0	8	0	3	9	0.73	1.00	0.85	0.71
L06	0	0	9	5	2	4	0.82	0.44	0.65	0.27
L07	0	2	9	0	1	8	0.90	1.00	0.94	0.73
L08	0	2	6	0	5	7	0.55	1.00	0.72	0.38
L09	1	0	4	0	6	9	0.40	1.00	0.68	0.39
L10	0	0	10	0	1	9	0.91	1.00	0.95	0.90
L11	0	0	7	0	4	9	0.64	1.00	0.80	0.61
L12	0	1	6	0	4	9	0.60	1.00	0.79	0.54
L13	0	1	11	0	0	8	1.00	1.00	1.00	0.90
L14	0	1	7	0	3	9	0.70	1.00	0.84	0.63
L15	0	0	9	0	2	9	0.82	1.00	0.90	0.80
L16	0	1	8	0	2	9	0.80	1.00	0.89	0.72
L17	2	0	8	2	3	5	0.73	0.71	0.72	0.43
L18	0	0	8	2	3	7	0.73	0.78	0.75	0.50
L20	0	1	11	2	0	6	1.00	0.75	0.89	0.70
L21	3	7	4	2	0	4	1.00	0.67	0.80	0.25
L22	0	1	7	0	3	9	0.70	1.00	0.84	0.63
L23	0	0	5	0	6	9	0.45	1.00	0.70	0.43
L24	0	2	10	0	1	7	0.91	1.00	0.94	0.72
L25	4	0	4	3	5	4	0.44	0.57	0.50	0.02
L27	0	0	11	0	0	9	1.00	1.00	1.00	1.00
L28	0	0	10	7	1	2	0.91	0.22	0.60	0.14
L29	0	2	7	0	3	8	0.70	1.00	0.83	0.55

Missing: Samples with no result due to shipping and/or receiving error–excluded from analysis.

Inconclusive: Samples with inconclusive result as classified by laboratory, unable to determine a positive or negative results. Excluded from the sensitivity and specificity calculations, but included in the kappa calculations.

a: True Positive

b: False Positive

c: False Negative

d: True Negative

Concordance: percent of laboratory results in agreement the CDC

Kappa: Cohen's kappa coefficient measures inter-rater agreement considering agreement occurring by chance.