Table 2.

Estimated power to detect multivitamin effects on CD4 count change over 18 months of follow-up (n=400)

Mean difference in CD4 change (δ, in cells/mm3)	Standard deviation of CD4 counts at baseline and follow-up (σ1= σ2, in cells/mm3)		Correlation of CD4 counts between baseline and follow-up (ρ)
		0.5	0.6	0.7
40	175	58	68	80
	225	39	47	59
50	175	77	86	94
	225	56	66	78
60	175	90	95	99
	225	72	81	90
70	175	97	99	>99
	225	84	91	97