Twenty-nine studies (n=7,827) were included in the review. Sample sizes ranged from 30 to 1,065 (n=1,053 was stated in the text). Jadad quality scores ranged from 3 to 5 points: nine studies scored 5 points, 10 scored 4 points and 10 scored 3 points.
Safety (25 studies, 26 study arms):
Where reported, between zero and 16% of patients in the treatment group withdrew (5.8% to 38% discontinued) and between zero and 11.1% in the placebo group withdrew (5.1% to 46% discontinued).
Compared with placebo, A1B use was associated with a statistically significant increase in the development of a vascular-related event (OR 2.54, 95% CI 2.00 to 3.24; 26 study arms); statistical heterogeneity could not be ruled out.
Subgroup analyses according to A1B type showed a significant increase in the development of a vascular-related event for alfuzosin (OR 1.66, 95% CI 1.17 to 2.36; four study arms), terazosin (OR 3.71, 95% CI 2.48 to 5.53; seven study arms), doxazosin (OR 3.32, 95% CI 2.10 to 5.23; six study arms) and doxazosin GITS (OR 3.86, 95% CI 1.86 to 8.02; two study arms). No significant difference in development of a vascular-related event was reported for tamsulosin (OR 1.42, 95% CI 0.99 to 2.05; seven study arms). Subgroup analyses showed no evidence of significant statistical heterogeneity with the exception of the studies that assessed doxazosin.
Efficacy (26 studies):
Compared with placebo, A1Bs significantly increased Qmax (WMD 1.32mL/min, 95% CI 1.07 to1.57) and decreased AUA-SI/IPSS (WMD -1.92, 95% CI -2.71 to -1.14). Subgroup analyses were reported in the review.
There was no evidence of publication bias.