BackgroundPatient advisory councils are a way for healthcare organizations to promote patient engagement. Despite mandates to implement patient advisory councils through programs like the Patient-Centered Medical Home (PCMH), there is a paucity of data measuring the impact of patients functioning in advisory roles. Our objective is to investigate whether patient engagement in patient advisory councils is linked to improvements in clinical quality, patient safety or patient satisfaction.MethodsWe searched PubMed, SCOPUS, CINAHL and Google Scholar for English language publications between November 2002 to August 2015, using a combination of “patient advisor” and “care outcomes” search terms. Article selection utilized dual screening facilitated by DistillerSR software, with group discussion to resolve discordance. Observational studies, randomized controlled trials, and case studies were included that described patients serving in an advisory role where primary outcomes were mentioned. Reference lists of included studies and grey literature searches were conducted. Qualitative thematic analysis was performed to synthesize results.ResultsDatabase searching yielded 639 articles total after removing duplicates, with 129 articles meeting full text inclusion criteria. 32 articles were identified for final review, 16 of which were case studies. Advisory roles included patient advisory councils, ad-hoc patient committees, community advisory councils, experience-based co-design, and other. Four practice-based studies from one research group, involving community advisors in the design of public health interventions, found improved clinical outcomes. No prospective experimental studies assessed the impact of patient advisors on patient safety or patient satisfaction. One cluster-randomized RCT showed that patient advisors helped health care planning efforts identify priorities more aligned with the PCMH. Ten case studies reported anecdotal benefit to individual patient advisors.ConclusionFive included studies demonstrate promising methods for evaluating patient engagement in healthcare delivery and describe impacts on clinical outcomes and priority setting. Based on the case studies found, patient advisors tend to contribute to patient-facing services that may affect clinical care but are not easily evaluated. As clinics and hospitals implement patient advisory councils, rigorous evaluation of their programs is needed to support the expansion of system-level patient engagement.Trial registrationThis systematic review was registered in the PROSPERO database of the University of York Centre for Reviews and Dissemination (ID: 2015:CRD42015030020).Electronic supplementary materialThe online version of this article (10.1186/s12913-017-2630-4) contains supplementary material, which is available to authorized users.