Table 1.

Five-stage criteria for the early termination of the areca nut/betel quid cessation study known as the Betel Nut Intervention Trial.

Stage	Overall Number	Number Per Arm	Rejection Area	P-value
1	60	30	|Z| > 4.5617	0.000005
2	118	59	|Z| > 3.22564	0.0012
3	176	88	|Z| > 2.63372	0.0084
4	234	117	|Z| > 2.28087	0.0226
5	292	146	|Z| > 2.04007	0.0413