Strength of recommendation
A: Based on a well-done meta-analyses
Khan N, McAlister FA. Re-examining the efficacy of beta-blockers for the treatment of hypertension: a meta-analysis. CMAJ 2006; 174:1737– 1742.1
Wiysonge CS, Bradley H, Mayosi BM, et al. Beta-blockers for hypertension. Cochrane Database Syst Rev 2007; (1):CD002003.