Do HMOs make a difference? Introduction.

Abstract

The study presented in this and the following five papers analyzes how health maintenance organizations (HMOs) affect privately insured individuals' access to health care, use of services, and assessments of care. Using a common data source and methodology, the study examines differences in a broad range of measures between HMOs and other types of insurance, controlling for health status and an extensive set of other individual characteristics and market location. HMO/non-HMO differences also are examined across population subgroups defined by health status, income, race, and age. Data come from the Community Tracking Study Household Survey, a recent, large national survey. Findings show that a person's type of health insurance coverage has little effect on the likelihood of unmet or delayed needs for medical care in the aggregate, but the types of access problems faced by HMO and non-HMO enrollees differ. HMO enrollees are less likely to face financial barriers to care, but more likely to face barriers related to the organization of care delivery. HMO enrollees use more ambulatory and preventive care, but results show no differences in hospital, surgery, and emergency room use. Compared with other types of insurance, physician visits under HMOs are more likely to be to primary care physicians than to specialists. Finally, across nearly all measures of patients' satisfaction, ratings of their last doctor's visit, and trust in their physicians, HMO enrollees' assessments of care are lower than those of people not in HMOs. Across all measures, the study finds few subgroup differences.