Table 1.

Comparison of the number of patient contacts identified by a tag-based real-time locating system within the vicinity of the NCID and the TraceTogether app on iPhones and Android phones.

Phone type and physician number		RTLSa	TraceTogetherb	RTLS+TraceTogether	RTLS or TraceTogether	Sensitivity of RTLSc (%)	Sensitivity of TraceTogetherd (%)
iPhones
	1	65	0	0	65	100	0
	2	52	0	0	52	100	0
	3	2	0	0	2	100	0
	4	70	0	0	70	100	0
	5	59	4	1	64	93.8	7.8
	6	9	3	0	12	75	25
	7	14	0	0	14	100	0
	8	18	2	0	20	90	10
	9	59	0	0	59	100	0
	10	14	0	0	14	100	0
	Total	362	9	1	372	97.6	2.7e
Android phones
	11	83	1	2	86	98.8	3.5
	12	61	0	0	61	100	0
	13	11	0	1	12	100	8.3
	14	78	5	2	85	94.1	8.2
	15	12	0	0	12	100	0
	16	80	12	6	98	87.8	18.4
	17	43	2	0	45	95.6	4.4
	18	42	10	3	55	81.8	23.6
	Total	410	30	14	454	93.4	9.7e
iPhone+Android Phone
	Total	772	39	15	826	95.3	6.5

^aRTLS: real-time locating system.

^bTraceTogether-only data includes contacts that were concurrently detected by the TraceTogether app and the NCID location-based RTLS to ensure that the encounters were within NCID’s vicinity.

^cRTLS sensitivity = (number of contacts detected by RTLS + (RTLS+TraceTogether))/(number of contacts detected RTLS or TraceTogether).

^dTraceTogether sensitivity = (number of contacts detected by TraceTogether + (RTLS+TraceTogether))/(number of contacts detected by RTLS or TraceTogether).

^eP<.001 when the sensitivity of TraceTogether was compared between Android phones and iPhones.