Table 1.

Disease risk probability and detection: Group size at level 1 and potential grouping at level 2.

Disease risk %	Sample size at level 1	Prob for 2nd positive	Group # at level 2	Minimum size independent detection %	Minimum size dependent detection %	Sample size %	Total dependent detection %
10	6	0.111111	2	50	25	75	50
9	7	0.098901	3	33	22	56	67
8	8	0.086957	4	25	19	44	75
7	9	0.075269	5	20	16	36	80
6	10	0.06383	6	17	14	31	83
5	13	0.052632	7	14	12	27	86
4	16	0.041667	8	13	11	23	88
3	22	0.030928	9	11	10	21	89
2	33	0.020408	10	10	9	19	90
1	66	0.010101	11	9	8	17	91
0.9	74	0.009082	12	8	8	16	92
0.8	83	0.008065	13	8	7	15	92
0.7	95	0.007049	14	7	7	14	93
0.6	111	0.006036	15	7	6	13	93
0.5	134	0.005025	16	6	6	12	94
0.4	167	0.004016	17	6	6	11	94
0.3	223	0.003009	18	6	5	11	94
0.2	335	0.002004	19	5	5	10	95
0.1	671	0.001001	20	5	5	10	95
0.09	745	0.000901	20	5	5	10	95
0.05	1000	0.0005	20	5	5	10	95
0.01	1000	0.0001	20	5	5	10	95