People's trust in the health system plays a role in explaining one's access to and utilization of medical care, adherence to medications, continuity of care, and even self-reported health status. Yet it is not easy to find trust measures and understand what they are measuring. A systematic review of scales and indices identified 45 measures of trust within the health system with an average of 12 questions each, which quantified levels of trust among various relationships across the health system.