Evaluating health service outcomes of public involvement in health service design in high-income countries: a systematic review

BACKGROUND: Internationally, it is expected that health services will involve the public in health service design. Evaluation of public involvement has typically focused on the process and experiences for participants. Less is known about outcomes for health services. The aim of this systematic review was to a) identify and synthesise what is known about health service outcomes of public involvement and b) document how outcomes were evaluated. METHODS: Searches were undertaken in MEDLINE, EMBASE, The Cochrane Library, PsycINFO, Web of Science, and CINAHL for studies that reported health service outcomes from public involvement in health service design. The review was limited to high-income countries and studies in English. Study quality was assessed using the Mixed Methods Appraisal Tool and critical appraisal guidelines for assessing the quality and impact of user involvement in health research. Content analysis was used to determine the outcomes of public involvement in health service design and how outcomes were evaluated. RESULTS: A total of 93 articles were included. The majority were published in the last 5 years, were qualitative, and were located in the United Kingdom. A range of health service outcomes (discrete products, improvements to health services and system/policy level changes) were reported at various levels (service level, across services, and across organisations). However, evaluations of outcomes were reported in less than half of studies. In studies where outcomes were evaluated, a range of methods were used; most frequent were mixed methods. The quality of study design and reporting was inconsistent. CONCLUSION: When reporting public involvement in health service design authors outline a range of outcomes for health services, but it is challenging to determine the extent of outcomes due to inadequate descriptions of study design and poor reporting. There is an urgent need for evaluations, including longitudinal study designs and cost-benefit analyses, to fully understand outcomes from public involvement in health service design. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-021-06319-1.