borderline significantP = 0.05
The test for subgroup differences was borderline significant, P = 0.05, I 2 = 0%.
The test for subgroup differences was borderline significant, P = 0.05, I 2 = 0%.
Trials using more than 500 μg per day of selenium showed a trend towards a lower mortality (RR = 0.80, 95% CI 0.63 to 1.02, P = 0.07) whereas trials using doses lower than 500 μg had no effect on mortality (RR 0.94, 95% CI 0.67 to 1.33, P = 0.75).