“…Systematic review and other overviews have tried to compile existing clinical evidence on the effects of combination therapy [4][5][6][7][8][9][10][11][12]. In general, meta-analyses of observational studies have shown a benefit for combination therapy [8,11], whilst those including randomised controlled trials (RCTs) have not [4][5][6][7]9,10,12]. These reviews approached the question from different perspectives, each addressing a specific clinical scenario [Gram-negative bacteraemia, febrile neutropenia, empirical treatment of sepsis, endocarditis, ventilator-associated pneumonia, cystic fibrosis (CF)], with different study designs, different definitions of combination therapy and different outcomes.…”