Background Poor translation of clinical practice guidelines (CPGs) into clinical practice is a barrier to the provision of consistent and high-quality evidence-based care. The objective was to systematically review the roles and effectiveness of knowledge brokers (KBs) for translating CPGs in health-related settings.

Methods MEDLINE, Embase, PsycINFO and CINAHL Plus were searched from 2014 to June 2022. Randomised controlled trials (RCTs), controlled and uncontrolled preintervention and postintervention studies involving KBs, either alone or as part of a multicomponent intervention, that reported quantitative postintervention changes in guideline implementation in a healthcare setting were included. A KB was defined as an intermediary who facilitated knowledge translation by acting in at least two of the following core roles: knowledge manager, linkage agent or capacity builder. Specific activities undertaken by KBs were deductively coded to the three core roles, then common activities were inductively grouped. Screening, data extraction, quality assessment and coding were performed independently by two authors.

Results 16 studies comprising 6 RCTs, 8 uncontrolled precomparisons–postcomparisons, 1 controlled precomparison–postcomparison and 1 interrupted time series were included. 14 studies (88%) were conducted in hospital settings. Knowledge manager roles included creating and distributing guideline material. Linkage agent roles involved engaging with internal and external stakeholders. Capacity builder roles involved audit and feedback and educating staff. KBs improved guideline adherence in 10 studies (63%), had mixed impact in 2 studies (13%) and no impact in 4 studies (25%). Half of the RCTs showed KBs had no impact on guideline adherence. KBs acted as knowledge managers in 15 (94%) studies, linkage agents in 11 (69%) studies and capacity builders in all studies.

Conclusion Knowledge manager and capacity builder roles were more frequently studied than linkage agent roles. KBs had mixed impact on translating CPGs into practice. Further RCTs, including those in non-hospital settings, are required.

PROSPERO registration number CRD42022340365.