. 2003 Apr;185(8):2555–2562. doi: 10.1128/JB.185.8.2555-2562.2003

TABLE 3.

Discrimination analysis of isolates with one to four bands by IS6110 and spoligotyping

No. of IS6110 bands	No. of bands		Degree of clustering^a	D(IS)^b	D(SP)^c	D(IS-SP)	Expected D(IS-SP)^c
No. of IS6110 bands	Total	Clustered	Degree of clustering^a	D(IS)^b	D(SP)^c	D(IS-SP)	Expected D(IS-SP)^c
1	131	131	97.7	0.434	0.938	0.940	0.965
2	92	82	83.7	0.419	0.885	0.894	0.933
3	59	49	67.8	0.877	0.889	0.928	0.986
4	55	40	61.8	0.786	0.911	0.947	0.981
Total	337	302	82.2	0.863	0.955	0.980	0.994

Degree of clustering was calculated as 100 × [(number of clustered isolates) − (number of clusters)]/total number of isolates.

D(IS), D(SP), and D(IS-SP) are discrimination indices for IS6110 typing, spoligotyping, and combined IS6110 and spoligotyping data, respectively.

The expected value of D(IS-SP), if the two tests were independent, was calculated as 1 − {[1 − D(IS)][1 − D(SP)]}.