Prior healthcare utilization as a predictor of survival for medical intensive care unit patients.

Objective: To determine whether measures of inpatient care utilization from the year preceding admission to a medical intensive care unit (MICU) improve physiology-based predictions of hospital and 1-yr survival.

Design: Inception cohort study with a validation cohort.

Setting: The MICU in university-affiliated Department of Veterans Affairs Medical Center.

The Medicare-HMO revolving door--the healthy go in and the sick go out.

Background: Enrollment in Medicare health maintenance organizations (HMOs) is encouraged because of the expectation that HMOs can help slow the growth of Medicare costs. However, Medicare HMOs, which are paid 95 percent of average yearly fee-for-service Medicare expenditures, are increasingly believed to benefit from the selective enrollment of healthier Medicare recipients. Furthermore, whether sicker patients are more likely to disenroll from Medicare HMOs, thus raising average fee-for-service costs, is not clear.