Pilot Study of Disenrollment Among HMO Patients with Cancer

Background

HMO disenrollment among cancer patients during the five years after initial diagnosis is of interest for several reasons. As the Cancer Research Network (CRN) designs survivorship and quality of care studies, we need to know disenrollment rates and the characteristics of cancer patients who disenroll in order to determine sample sizes and assess potential biases. This pilot study was designed to provide CRN investigators with information to support future proposals to study patterns and quality of care and survivorship issues, allow assessment of the feasibility of establishing on-going tracking of disenrollment patterns among enrollees with cancer, and contribute to the development of subsequent proposals that directly address reasons for disenrollment.

Study Aims

1. At each participating site, determine the yearly rates of disenrollment among cancer patients for all causes and for reasons other than death during the first and up to five years following diagnosis, and identify variation in rates across years of diagnosis.
2. Determine yearly disenrollment rates for all causes and for reasons other than death during the first and up to five years following diagnosis specifically for breast, prostate, lung, and colon cancers for each site, and assess cross-CRN site variation in these rates. For lung cancer, the focus was on disenrollment during the first two years after diagnosis, while for breast, prostate, and colon cancers disenrollment was followed for the full five years.
3. Determine yearly disenrollment rates for all causes and for reasons other than death during the first and up to five years following diagnosis specifically for breast, prostate, lung, and colon cancers combining all sites. As in aim 2, the focus among enrollees with lung cancer was on the first two years after diagnosis, while for breast, prostate, and colon cancers disenrollment was followed for the full five years.
4. Assess the relationship between disenrollment for reasons other than death during the first year after diagnosis and the following characteristics of cancer patients: age, gender, race, type of cancer, cancer stage, year of diagnosis, CRN site, insurance type at the time of diagnosis, and length of enrollment prior to diagnosis.

Methods

This pilot project was primarily a descriptive cohort study, assessing the yearly disenrollment rates among enrollees of the five plans who were diagnosed with cancer between January 1, 1993 and December 31, 1998 through follow-up periods of up to five years. Two forms of disenrollment were evaluated- all cause and for any cause other than death. Key data elements pertaining to the cancer and the enrollment status were collected on over 130,000 enrollees. During the study, several tools were developed that will be of utility for subsequent CRN studies, including standardized data dictionaries, variable definitions, response categories, and specific data testing programs.

Significance

Disenrollment for reasons other than death has broader implications since it may serve as a marker for problems with access to care and patients' perceptions of quality or of loss of insurance coverage, issues that are of particular concern for patients with life-threatening or chronic illnesses.

Project Status

This project was funded as an administrative supplement to the CRN. The project leader was Terry Field, DSc, from the Meyers Primary Care Institute of the University of Massachusetts / Fallon Healthcare System. Results from the study are pending publication in the Journal of the National Cancer Institute.