In order to further reinforce the conclusion above， subgroup analyses based on the treatment dosages was performed. An X2 test to examine the heterogeneity was performed； the results were P = 0.06(<0.10)， I2 = 59% (>50%)； P = 0.76(>0.10)， I2 = 0% (<50%) and P = 0.02 (<0.10)， I2 = 80 %(> 50%)， respectively， which indicated that there was heterogeneity. Therefore， a random-effect model was used. The results (RR= 1.26； 95%CI = 0.84 to 1.88； P= 0.27 for 0.2mg tamsulosin； RR = 1.08； 95%CI = 1.00 to 1.15； P=0.04 for 0.4mg tamsulosin； RR = 1.11； 95% CI = 0.93 to 1.33； P= 0.26 for 0.8mg tamsulosin and the total RR=1.11； 95%CI = 1.04 to 1.18) indicated that there were significant differences between the tamsulosin groups and the placebo groups for AEs. This is the first instance in which the Tamsulosin groups did less well in comparison to the placebo group (Figure 5).

    Table3 summarizes all of the reported adverse events. Regarding individual events ......