Final answer:
The Healthcare Effectiveness Data and Information Set (HEDIS) is primarily used by health maintenance organizations (HMOs) to measure their performance in providing healthcare services.
Step-by-step explanation:
The Healthcare Effectiveness Data and Information Set (HEDIS) is a tool used by most health maintenance organizations (HMOs) and PPO plans to measure performance on important dimensions of care and service. HMOs provide healthcare that receives a fixed amount per person enrolled in the plan, which is a shift from the traditional fee-for-service basis that was more common in the past. This system intends to reduce the moral hazard by incentivizing providers to offer efficient care while managing the resources among patients.