How do you measure trust in social institutions and health professionals? A systematic review of the literature (2012-2021)

The importance of measuring trust in health systems has been accentuated due to its correlation with important health outcomes aimed at reducing COVID-19 transmission. A systematic review published almost a decade ago identified gaps in measures including the lack of focus on trust in systems, inconsistency regarding the dimensionality of trust and need for research to strengthen the validity of measures. Given developments in our understandings of trust since its publication, we sought to identify new scales developed, existing ones adapted in response to identified gaps, and agendas for future research. Using the PRISMA approach for systematic reviews, we conducted a search in four databases. A total of 26 articles were assessed. Twelve new scales were identified, while 14 were adapted for different settings and populations. Literature continues to focus on measuring trust in health professionals rather than systems. Various shortcomings were identified, including some articles not mentioning the dimensions included in the scale and suboptimal use of validity and reliability testing and/or reporting. Moreover, a variety of terms were used for dimensions. Future research is needed to address these gaps and consequently, to understand their correlation with health behaviours and outcomes more accurately