Carolyn W. Madden

Modeling risk using generalized linear models

Traditionally, linear regression has been the technique of choice for predicting medical risk. This paper presents a new approach to modeling the second part of two-part models utilizing extensions of the generalized linear model. The primary method of estimation for this model is maximum likelihood. This method as well as the generalizations quasi-likelihood and extended quasi-likelihood are discussed. An example using medical expense data from Washington State employees is used to illustrate the methods. The model includes demographic variables as well as an Ambulatory. Care Group variable to account for prior health status.

Vertical structures and control in health care markets: a conceptual framework and empirical review.

Dr. Conrad is Professor, Department of Health Services, and Director, Graduate Program in Health Services Administration, Department of Health Services, School of Public Health and Community Medicine, University of Washington, Seattle, WA. Dr. Mick is Associate Professor and Head, Division of Health, Finance and Management, Department of Health Policy and Management, School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, MD. Dr. Madden is Associate Professor, Graduate Program in Health Services Administration and Director, Health Policy Analysis Program, Department of Health Services, School of Public Health and Community Medicine, University of Washington. Dr. Hoare is Assistant Professor, Graduate Program in Health Services Administration, Department of Health Services, School of Public Health and Community Medicine, University of Washington. ~

WHO ENROLLED IN A STATE PROGRAM FOR THE UNINSURED : WAS THERE ADVERSE SELECTION ?

Managed care plans may hesitate to participate in programs for uninsured persons because they fear adverse selection, whereby only the sickest people or highest users would choose to join the program. We studied this issue in Washington States Basic Health Flan, a demonstration program that provides subsidized health insurance for families earning less than 200% of the poverty level. We interviewed people in three counties who enrolled in the program, and compared them to people in the same counties who were eligible but did not enroll. There were substantial differences between enrollees and eligibles in education, age, income, employment, race, and insurance status. In spite of these demographic and access differences, health status was remarkably similar for enrollees and eligibles, with the few significant differences favoring the enrollees. In addition, previous and subsequent use of health services was similar or lower for enrollees. The results for health status and utilization were similar across the three counties, even though the counties and the providers were quite different. We conclude that there is no evidence of adverse selection. This is welcome news for the health plans, but suggests that the BHP may not have reached those most in need of insurance.

Will uninsured people volunteer for voluntary health insurance? Experience from Washington State.

OBJECTIVES In national and local discussions of health care reform, there is disagreement about whether a national health insurance plan should be mandatory or voluntary. This study describes characteristics of low- income people who were more likely or less likely to be covered by a voluntary plan. METHODS Survey data were available from an evaluation of Washington States Basic Health Plan, which offered subsidized health insurance to low-income residents. For those subjects who were eligible and uninsured at baseline, those who joined were compared with those who did not join on a variety of demographic and health-related characteristics. RESULTS There were substantial differences between those who did and did not join the Basic Health Plan. Those who did not enroll were generally less well-off, with less education, lower income, and worse health. Many had never had health insurance. CONCLUSIONS If health care reform results in a voluntary plan, additional measures may be needed to ensure that less advantaged citizens have adequate access to health care.

Voluntary Public Health Insurance for Low-Income Families: The Decision to Enroll

A dominant issue in the health reform debate is whether insurance coverage should be voluntary or mandatory. Clearly, the factors that determine who will seek voluntary coverage are relevant to this policy issue. This article uses experience from Washington States Basic Health Plan to examine the enrollment choices of low-income families in a state-subsidized voluntary insurance plan offered through managed care organizations. We hypothesize that the decision to enroll, which encompasses the decisions to purchase insurance coverage and to select a particular plan, is influenced by four factors: the familys financial vulnerability, their risk perception, the price of coverage, and the transition costs of enrolling. Our enrollment model is supported by the data and has important implications for the design of voluntary programs. Families who choose to enroll are more likely to have a female head of household, young children, and a family member who has a part-time job and some college education. Higher premiums and availability of other insurance coverage decrease the probability of enrolling.

Washington State's Basic Health Plan: choices and challenges.

The current turbulence characterizing the health sector has engendered a limited number of state-level experiments to provide health services for the nations 37 million uninsured. The issues and challenges generated by each programs design and implementation vary. By examining the experience of one such state program, the Washington Basic Health Plan, in some detail, this paper contributes to the policy debate regarding the possible range of solutions available to address the issue of “the uninsured.” By analyzing the array of design choices available at the time the program was enacted, and why certain options were chosen rather than others, this paper points to the complex interaction of political dynamics, public policy development, and program implementation.