BackgroundExtensive research has been conducted into the effects of feedback interventions within many areas of healthcare, but prehospital emergency care has been relatively neglected. Exploratory work suggests that enhancing feedback and follow-up to emergency medical service (EMS) staff might provide staff with closure and improve clinical performance. Our aim was to summarise the literature on the types of feedback received by EMS professionals and its effects on the quality and safety of patient care, staff well-being and professional development.MethodsA systematic review and meta-analysis, including primary research studies of any method published in peer-reviewed journals. Studies were included if they contained information on systematic feedback to emergency ambulance staff regarding their performance. Databases searched from inception were MEDLINE, Embase, AMED, PsycINFO, HMIC, CINAHL and Web of Science, with searches last updated on 2 August 2022. Study quality was appraised using the Mixed Methods Appraisal Tool. Data analysis followed a convergent integrated design involving simultaneous narrative synthesis and random effects multilevel meta-analyses.ResultsThe search strategy yielded 3183 articles, with 48 studies meeting inclusion criteria after title/abstract screening and full-text review. Interventions were categorised as audit and feedback (n=31), peer-to-peer feedback (n=3), postevent debriefing (n=2), incident-prompted feedback (n=1), patient outcome feedback (n=1) or a combination thereof (n=4). Feedback was found to have a moderate positive effect on quality of care and professional development with a pooled effect of d=0.50 (95% CI 0.34, 0.67). Feedback to EMS professionals had large effects in improving documentation (d=0.73 (0.00, 1.45)) and protocol adherence (d=0.68 (0.12, 1.24)), as well as small effects in enhancing cardiac arrest performance (d=0.46 (0.06, 0.86)), clinical decision-making (d=0.47 (0.23, 0.72)), ambulance times (d=0.43 (0.12, 0.74)) and survival rates (d=0.22 (0.11, 0.33)). The between-study heterogeneity variance was estimated at σ2=0.32 (95% CI 0.22, 0.50), with an I2value of 99% (95% CI 98%, 99%), indicating substantial statistical heterogeneity.ConclusionThis review demonstrated that the evidence base currently does not support a clear single point estimate of the pooled effect of feedback to EMS staff as a single intervention type due to study heterogeneity. Further research is needed to provide guidance and frameworks supporting better design and evaluation of feedback interventions within EMS.PROSPERO registration numberCRD42020162600.