In 2003 investigators at New England Medical Center Hospitals, Boston, collected four-year follow-up data from a cohort of Medicare beneficiaries under study since 1998 to examine differences in health outcomes related to physical and mental health and death for beneficiaries enrolled in traditional fee-for-service Medicare versus those enrolled in Medicare HMOs.
While many studies have examined performance differences between traditional fee-for-service Medicare and Medicare HMOs, results have been inconclusive.
Researchers reported findings in a December 2004 report to the federal Agency for Healthcare Research and Quality entitled Comparing Four-Year Health Outcomes Among Elderly Adults in Traditional (FFS) Medicare and Medicare HMOs.
There were no statistically significant differences in outcomes relating to physical and mental health or death after four years between elderly individuals enrolled in traditional fee-for-service Medicare and those enrolled in Medicare HMOs, after accounting for population differences.
Analysis of those who changed Medicare systems during the study period ("switchers") supported previous research findings that sicker patients are more likely to choose fee-for-service plans while healthier individuals tend to choose HMOs.
The addition of Medicaid coverage had a slight, but not statistically significant, favorable impact on physical health outcomes.