“…RCTs (both cluster 11−17 and individual patient 18−21 designs), as well as prospective 22−31 and retrospective 32−39 studies have investigated the impact of guideline adherence on financial costs 11,12,14,16,17,19,22,24−28,30−40 and patient outcomes. 12,13,15,18,20,21,23,24,29,[33][34][35]37,41 Retrospective studies have shown lower costs 32−36,38−40 when guidelines are followed. Prospective non-randomised studies 22,[24][25][26][27][28]30,31 are less consistent, yet appear dependent on the modality of intervention examined.…”