Table 3.

Relative risk of major cardiovascular outcomes by randomized intervention within subgroups in the Women’s Antioxidant Cardiovascular Study.^*

	Vitamin C				Vitamin E				Beta-carotene
Baseline Factor	Active	Placebo	RR (95% CI)	p	Active	Placebo	RR (95% CI)	p	Active	Placebo	RR (95% CI)	p
Age (years)
40-54	111	123	0.90 (0.70-1.17)	0.44	117	117	1.01 (0.78-1.30)	0.95	115	119	0.97 (0.75-1.25)	0.82
55-64	269	244	1.12 (0.94-1.33)	0.20	246	267	0.91 (0.77-1.09)	0.30	252	261	0.96 (0.81-1.15)	0.68
65+	351	352	0.99 (0.85-1.15)	0.91	345	358	0.94 (0.81-1.09)	0.39	364	339	1.08 (0.93-1.25)	0.31
Health history
Prior CVD	592	567	1.05 (0.93-1.18)	0.43	558	601	0.89 (0.79-1.00)	0.04	580	579	1.02 (0.91-1.14)	0.77
3+ risk factors	139	152	0.93 (0.74-1.16)	0.51	150	141	1.13 (0.89-1.42)	0.32	151	140	1.06 (0.84-1.34)	0.60
Smoking status
Current	139	158	0.92 (0.73-1.16)	0.48	151	146	1.05 (0.84-1.32)	0.68	152	145	1.12 (0.89-1.40)	0.34
Past or never	592	561	1.05 (0.94-1.18)	0.38	557	596	0.91 (0.81-1.02)	0.12	579	574	1.00 (0.89-1.12)	0.98
Alcohol use in past year
Never	443	442	0.97 (0.85-1.11)	0.68	427	458	0.95 (0.83-1.08)	0.43	461	424	1.08 (0.95-1.23)	0.24
Ever	288	277	1.08 (0.92-1.28)	0.35	281	284	0.94 (0.79-1.11)	0.44	270	295	0.92 (0.78-1.09)	0.35
Body mass index
<25 kg/m2	192	170	1.17 (0.95-1.44)	0.14	167	195	0.88 (0.71-1.08)	0.22	197	165	1.09 (0.88-1.34)	0.43
25-<30 kg/m2	229	225	0.98 (0.81-1.18)	0.82	233	221	0.98 (0.81-1.18)	0.81	210	244	0.89 (0.74-1.07)	0.21
30+ kg/m2	310	323	0.97 (0.83-1.14)	0.73	307	326	0.94 (0.80-1.10)	0.43	323	310	1.08 (0.93-1.27)	0.32
History of hypertension
Yes	583	591	0.98 (0.87-1.09)	0.68	570	604	0.95 (0.84-1.06)	0.35	595	579	1.01 (0.90-1.13)	0.87
No	148	128	1.21 (0.95-1.53)	0.12	138	138	0.93 (0.73-1.18)	0.54	136	140	1.03 (0.82-1.31)	0.78
Diabetes
Yes	232	235	0.96 (0.80-1.15)	0.63	222	245	0.92 (0.77-1.11)	0.38	244	223	1.09 (0.91-1.31)	0.34
No	499	484	1.04 (0.92-1.18)	0.52	486	497	0.95 (0.84-1.08)	0.45	487	496	0.99 (0.87-1.12)	0.82
Menopause and HT use
Premenopausal	26	30	0.92 (0.54-1.55)	0.74	31	25	1.26 (0.74-2.13	0.40†	24	32	0.82 (0.48-1.40)	0.47
Uncertain	77	65	1.16 (0.83-1.61)	0.39	60	82	0.70 (0.50-0.98)	0.04	74	68	1.06 (0.77-1.48)	0.71
Post, current HT	277	252	1.07 (0.90-1.27)	0.45	279	250	1.10 (0.93-1.31)	0.27	280	249	1.10 (0.92-1.30)	0.29
Post, no HT	337	359	0.96 (0.83-1.11)	0.59	328	368	0.88 (0.76-1.02)	0.08‡	338	358	0.96 (0.83-1.11)	0.60
Current multivitamin use
Yes	173	194	0.89 (0.72-1.09)	0.26	179	188	0.92 (0.75-1.13)	0.42	183	184	0.99 (0.81-1.22)	0.94
No	551	518	1.07 (0.95-1.21)	0.28	525	544	0.96 (0.85-1.08)	0.46	540	529	1.02 (0.90-1.15)	0.76

^*Abbreviations: CVD = cardiovascular disease; Vit = vitamin; Plac = placebo; RR = relative risk; CI = confidence interval; HT = hormone therapy; Post = postmenopausal. Baseline factors are defined as in Table 1.

^†P for interaction < 0.05.

^‡Among post-menopausal women, p < 0.05 for interaction comparing HT users vs. non-users.