Three-Year Study of One Employer with CDHC, PPO, and HMO

In a study of one self-insured employer with 20,000 employees, the researchers compared almost 3,700 "contracts" (each single employee or family coverage was considered a contract) for plan years 2000, 2001, and 2002, covering groups enrolled in an HMO or PPO for all three years and a group enrolled in an HMO or PPO in 2000 and then enrolled in a consumer-driven health care plan in 2001 and 2002. The researchers found those enrolling in the consumer-driven health care plan tended to be wealthier than enrollees in the other groups, with little difference in age and in number of enrollees among the groups.

The consumer-driven health care group began the period with fewer significant medical diagnoses than the PPO or HMO groups. Yet the consumer-driven group's diagnoses by the end of the year equaled or exceeded the HMO group, but remained less than that of the PPO group. Over the period, the consumer-driven health care enrollees had lower total expenditures than the PPO enrollees, but more than the HMO enrollees. Total hospital and doctor costs were significantly higher for the consumer-driven health care group than the HMO or PPO group, but drug costs for the consumer-driven group were significantly lower. The consumer-driven health care group also experienced a significant increase in hospital admissions, even though that plan provided no-cost preventive services.

This study's researchers feared the consumer-driven health care plan design skewed enrollee behavior because there was no copayment after the deductible was met each year. The researchers theorized this plan design may have encouraged the consumer-driven health care members to consume the medical accounts, but warned the data were too limited to support such a conclusion. The researchers cautioned their study had three limitations—it covered only one employer, some consumer-driven health care participants may have had "pent up" demand for health services, and the data systems of the three plan alternatives were not consistent, which could have skewed reporting of usage.

On balance these studies provide fairly divergent outcomes, making it impossible to conclude that the plans are guaranteed to succeed or to fail. But certainly, the plan designs indicate that plan design is important, regardless of the consumer-driven focus.