RAND Health, Skin in the Game: How Consumer-Directed Plans Affect the Cost and Use of Health Care. Key findings:

• “Families that switched from a traditional health plan to a consumer-directed health plan spent an average of 21 percent less on health care in the first year after switching than similar families remaining in traditional plans.
• Two-thirds of the savings came from initiating fewer episodes of care; one-third came from spending less per episode.
• Enrollees cut back on the use of some beneficial services, including preventive care, such as cancer screenings, even though such care was fully covered under consumer-directed plans.
• If the proportion of Americans with employer-sponsored insurance who enrolled in consumer-directed plans increased to 50 percent, annual health care costs would fall by an estimated $57 billion.”