TABLE 3.
Subgroup analyses of the effect of beta-carotene on total mortality.
| Subgroup title | No. of trials | No. of participants | I2 (%) | Risk ratio (95% CI) | P-value |
| Overall | 31 | 216,734 | 42.0 | 1.02 (0.98, 1.05) | 0.3 |
| No of participants | |||||
| ≥1,000 <1,000 |
15 16 |
212,980 3,754 |
58.0 4.0 |
1.02 (0.98, 1.05) 0.93 (0.83, 1.04) |
0.1 0.2 |
| No of events | |||||
| ≥100 <100 |
16 15 |
211,899 4,835 |
55.0 15.0 |
1.02 (0.99, 1.05) 0.88 (0.71, 1.09) |
0.2 0.3 |
| Age (years) | |||||
| ≥65 <65 |
11 20 |
12,879 203,855 |
0.0 56.0 |
1.00 (0.94, 1.07) 1.02 (0.98, 1.06) |
0.9 0.3 |
| Gender | |||||
| Women Men Women and men |
2 3 26 |
48,047 65,845 102,842 |
9.0 73.0 39.0 |
0.92 (0.72, 1.17) 1.01 (0.95, 1.08) 1.02 (0.97, 1.06) |
0.5 0.8 0.5 |
| Daily dose equivalent (mg) | |||||
| ≥ 20 < 20 |
15 16 |
155,812 60,922 |
55.0 0.0 |
1.02 (0.97, 1.08) 1.01 (0.99, 1.02) |
0.5 0.4 |
| Follow up | |||||
| At least 4 years Less than 4 years |
16 15 |
171,578 45,156 |
57.0 2.0 |
1.02 (0.98, 1.06) 0.94 (0.85, 1.04) |
0.3 0.2 |
| Intervention | |||||
| Beta carotene alone Combined |
4 27 |
2,343 214,391 |
0.0 47.0 |
0.96 (0.79, 1.16) 1.02 (0.98, 1.05) |
0.6 0.3 |
| Participant health status | |||||
| Healthy Unhealthy |
5 26 |
89,921 126,813 |
19.0 42.0 |
0.97 (0.91, 1.04) 1.03 (0.99, 1.07) |
0.4 0.1 |
| Control group | |||||
| Placebo No intervention |
30 1 |
216,520 214 |
43 - |
1.02 (0.99, 1.05) 0.63 (0.29, 1.39) |
0.3 0.25 |