Trust and mistrust shape how people engage with health organizations, influencing cooperation, compliance, and institutional legitimacy. While trust supports collective action, mistrust can reflect rational responses to inequity or institutional failure. Yet evidence on how these constructs are defined, measured, and addressed remains fragmented. This review synthesizes two decades of research to clarify definitions, determinants, measurement tools, and interventions related to trust and mistrust in health organizations. PRISMA guidelines were followed and the protocol was registered at PROSPERO registry for systematic reviews. We searched PubMed, Scopus, Web of Science and PsycINFO from inception to October 2025 for studies on trust or mistrust directed at health organizations. Eligible studies examined conceptualisations, determinants, instruments, and interventions. Two reviewers independently screened, extracted data, and appraised study quality (KMET, JBI). We included 149 studies from 52 countries (2003–2025); 71.8% came from high-income settings, and 92.6% were empirical, predominantly cross-sectional (55.7%). Trust was defined in 91.3% of studies; mistrust was conceptualized as a distinct construct shaped by structural, historical, and social inequities, rather than simply the absence of trust. Determinants clustered at individual, organizational, and systemic levels. Across quantitative studies, organizational characteristics constituted approximately two-thirds of all statistically tested predictors of trust, particularly transparent communication (42.3%), competence and service quality (38.3%), and perceived fairness (18.1%). Individual factors were key drivers of mistrust, while systemic factors were shaped by governance quality, corruption, and broader issues of equity. Only 29.5% of studies used validated instruments (14 distinct scales), mostly developed and applied in U.S. settings, with limited cross-cultural validation. Thirty-seven intervention studies (24.8%) evaluated strategies across five domains; community engagement and governance reforms showed the most consistent improvements in trust-related indicators, but evidence was largely short-term and rarely linked to behavioural or system-level outcomes. Trust functions as both a determinant and an indicator of equitable health-system performance. Progress requires validated, culturally adaptable measures and interventions that address the structural and historical roots of mistrust, especially among marginalized groups. Sustained investment in transparent governance, participatory communication, fair service delivery, and responsible digital infrastructures is essential to building trusted and resilient health organizations. Prospero Protocol number CRD420251155996.
Pelizzari et al. (Fri,) studied this question.