Table 1.

Subjects selected for the project

Groups		Placebo	Ca-only	Ca + D	Total	P
Initial subjects		288	445	446	1179
Exclusion	Not finished	44	54	58	155	0.46
	Metal prostheses/implants	36	60	52	148	0.71
	Cancer	20	17	13	50	0.03
Total excluded subjects		82	117	110	309	0.52
Applied subjects		206	328	336	870	0.52

Note: There were some overlaps between different exclusion criteria.

Not finished: subjects who did not finished the 4-year trial; Metal prostheses/implants: subjects with prosthetics or pacemakers implants; Cancer: subjects suffering from cancer during the 4-year trial.

P values were calculated by χ² test to compare the difference of ineligible subjects among the three groups.