Final answer:
Policy interventions primarily use social/public policy to influence the health of the population through government programs and regulations including welfare and healthcare financing.
Step-by-step explanation:
Policy interventions use social/public policy to affect the health of the population. Health policies, including those related to social welfare and regulation, government financing and providing healthcare, like Medicare and Medicaid, rely on this mechanism. They are a part of the broad strategy governments use to tackle various matters of concern to parts of society. Through public policy, the government engages in programs and regulatory processes that can change the health dynamics of a community or nation. Whether through removing lead from gasoline to reduce childhood lead exposure or using Medicare to aid the elderly, these social interventions are designed to have far-reaching impacts on a population's health. Policy analysts assess potential policies and predict their outcomes to aid in the creation of effective health strategies, while policy advocates work towards changing public policy based on their positions on issues.