“…Among the 15 parallel group studies, 7 studies [17][18][19]21,22,24,26 compared VBB with NVBB (n=186 for nonvasodilating β-blockers, n=209 for VBB); 2 studies 49,50 compared each 2 NVBB (atenolol versus bisoprolol); in 5 trials, β-blockers (3 NVBB 51-53 and 2 VBB 40,54 ) were compared against other antihypertensive classes; and in 1 case, a NVBB was tested against placebo. 55 Other antihypertensive drug classes were concomitantly administered in 5 studies (amlodipine, 51 hydrochlorothiazide, 23,53 lisinopril, 46 and lisinopril or losartan 22 ), whereas an add-on treatment approach with prespecified or unspecified other antihypertensive drug classes was allowed in 7 cases. 18,19,24,46,[52][53][54] In 9 studies, 18,20,23,47,48,[54][55][56] 19,21,22,24,50,51,53 ; and 1 study 26 did not report information about blindness of treatment.…”