Effects of bloodletting
Two trials reported the efficacy rate comparing bloodletting in the auricle to ADs, and meta-analysis from these two trials showed that there is no statistical difference between the groups in efficacy rate (RR, 0.65; 95% CI, 0.28–1.51, p=0.32; I2=0%). One trial compared bloodletting in the auricle to no intervention, and found the efficacy rate in the experimental group significantly higher than that in the control group (n=59 out of 61 patients; RR, 5.1; 95% CI 1.05–24.71; p=0.04), and also found a significant difference between the two groups in lowering both SBP (n=61 patients; MD, −8.77; 95% CI –10.20– −7.34, p<0.00001) and DBP (n=61 patients; MD, −5.50; 95% CI –7.24– −3.76, p<0.00001). As for the comparison of bloodletting in the auricle plus ADs versus ADs alone, three trials reported the efficacy rate, and two of them found a statistical difference between groups, one69 compared bloodletting in the auricle plus ADs to felodipine extended-release tablet or irbesartan alone (n=156 out of 178 patients; RR, 1.37; 95% CI, 1.21–1.55, p<0.00001); one study67 used nifedipine in the control group (n=57 out of 60 patients; RR, 1.21; 95% CI, 1.05–1.40, p=0.009). One trial used amlodipine besylate tablets in the control group and did not find a statistical difference between groups.68