Treatment with metformin and diet and lifestyle modifications both are cost-effective means of decreasing diabetes risk and improving quality of life.
Presenting a cost-utility analysis and other findings from research conducted through the NIH-sponsored Diabetes Prevention Program (DPP) at a press briefing at the ADA 71st Annual Scientific Sessions, William H. Herman, MD, MPH, reported that lifestyle intervention and metformin treatment are cost-effective methods for preventing type 2 diabetes (T2D) in patients at high risk.
The DPP was a randomized controlled trial that followed 3,234 high-risk participants assigned to one of three groups. The lifestyle intervention group received training in diet, exercise, and behavior modification. The metformin group received 850 mg/bid, and a third group received placebo. The metformin and placebo groups also received information about diet and exercise, but did not receive motivational counseling. After seven years of follow up, participants were given the option of participating in a diabetic prevention outcomes study. Together, researchers collected data spanning 10 years.
“A cost-utility analysis was conducted in part because of skepticism in the community that diabetes interventions were too expensive,” said Herman. The basic idea of the analysis was to determine costs associated with improving quality of life. In cost-utility analyses, the health outcome is described in terms of quality-adjusted life-years (QALY’s), which measure length of life adjusted for quality of life. A “health utility score” is assigned to quality of life that reflects the desirability of the outcome based on the societal preference for various health states. For example, perfect health would be rated 1.0 and death would be rated 0.0. A year of life for someone with diabetes, for example, may have a health utility score of 0.7.
Quality of life in study participants was improved with both lifestyle and metformin interventions compared to placebo. However, the costs (eg, direct medical) associated with the lifestyle intervention were $1500 more per participant compared to placebo over the 10 years of the study. This can be translated to a cost of $12,000 per QALY gained. In contrast, total direct costs associated with metformin were $30 less than placebo. Although the lifestyle intervention was associated with a higher cost, “it was ultimately more cost effective than placebo because the latter resulted in higher costs later on,” explained Herman. Specifically, the lifestyle intervention reduced the cost of medical care over 10 years by $2600. Metformin reduced costs by $1700.
In addition to improving quality of life, both interventions resulted in a reduction in development of T2D. Lifestyle intervention resulted in a 58% reduction and metformin resulted in a 31% reduction. “It is likely that the lifestyle intervention over a longer timeframe will have additional benefits in terms of lipid levels, cardiovascular fitness, quality of life, and other factors,” said Herman.
The goal is not necessarily to avoid paying for interventions, but rather determining “is this a good investment, a good value for your money?” When considering the improvements in quality of life and reductions in development of diabetes, Herman is convinced this is the case. He also pointed out that the “investment” of lifestyle intervention is on par with other widely accepted interventions such as using beta blockers after myocardial infarction, antihypertensive therapy, and statins for secondary prevention of cardiovascular disease. Herman said that he hopes to see changes in health care policies that encourage fewer costs associated with interventions. Regardless, both metformin and lifestyle interventions ultimately saved money and improved quality of life, “so they should both be widely accepted,” Herman said.