Abstract
BACKGROUND: Co-design is increasingly employed in healthcare to develop interventions that reflect the needs and preferences of patients and families. In paediatric settings, actively involving parents and guardians is particularly critical due to their central role in care delivery and decision-making. Despite growing interest in co-design, its implementation and impact in paediatric healthcare—especially in relation to parental engagement—remain inconsistently reported. This systematic review examines the use of co-design methodologies involving parents and guardians in developing paediatric healthcare interventions. METHODS: This review was conducted using Joanna Briggs Institute (JBI) methodology and was registered with PROSPERO (CRD42024550366). Seven databases (Medline, Embase, Global Health, CINAHL, PsycINFO, Cochrane, Web of Science) were searched for studies published from January 2000 to June 2025. Eligible studies employed co-design methods to develop paediatric healthcare interventions involving parents or guardians. Two reviewers independently screened records, extracted data on study characteristics, co-design methods, participants, intervention focus, and outcomes, and appraised quality using a customised JBI checklist. Findings were synthesised narratively to identify key themes. RESULTS: The search retrieved 12,574 citations. Seventy studies met the inclusion criteria, representing diverse designs including Participatory Action Research, Experience-Based Co-Design, Human-Centred Design, and mixed-methods. Across studies, 53,676 participants contributed, including parents/guardians, children, healthcare providers (clinicians, nurses), carers, and hospital policy makers. Interventions frequently addressed digital tools, communication, health education, and psychosocial supports. Outcomes were predominantly qualitative, reporting improved acceptability, usability, feasibility, and early implementation success. Reported challenges included power imbalances and scalability concerns, with limited explicit reporting on diversity, outcome consistency, or sustainability. CONCLUSION: Co-design with parents in paediatric healthcare supports the development of contextually relevant and acceptable interventions, with evidence of improved relevance, cultural alignment, and satisfaction in a subset of studies. However, reporting on outcome measurement remains inconsistent, and evidence on long-term sustainability and scale is limited. Future research should prioritise inclusive recruitment strategies, robust outcome evaluation (including economic analyses), and integration of co-designed interventions into routine clinical practice. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-025-13495-x.