San Diego, CA—Lifestyle intervention is cost-effective and metformin therapy is cost-saving in the prevention of type 2 diabetes in persons at high risk for developing the disease, said William H. Herman, MD, MPH, Professor of Medicine and Epidemiology, University of Michigan, Ann Arbor, at the 71st Scientific Sessions of the American Diabetes Association. These economic findings were derived from a 10-year cost analysis as a follow-up to the landmark Diabetes Prevention Program (DPP).
The National Institutes of Health–sponsored DPP showed that overweight and obese persons older than 35 years with impaired glucose tolerance who were assigned to intensive lifestyle intervention had a 58% reduction in the development of diabetes compared with placebo controls, and metformin was associated with a 31% reduction. The randomized portion of the study was stopped after 3 years, because of the effectiveness of the lifestyle intervention, and all participants were offered a less intensive lifestyle intervention. Those assigned to metformin were encouraged to continue with the drug. Follow-up of the groups continued for an additional 7 years. During the extended follow-up, the effectiveness of both treatments diminished: over the entire 10 years, intensive lifestyle intervention was associated with a 34% reduction in the development of diabetes, and metformin was associated with an 18% reduction.
The intervention costs were calculated, and a cost-utility analysis was performed. Compared with placebo over 10 years, treatment with metformin reduced the cost of medical care by $1700 per person, and intensive lifestyle intervention reduced it by $2600 per person. The reduction in cost came from fewer outpatient visits, fewer hospitalizations, and lower drug costs in the intervention groups as they forestalled or prevented incident diabetes, Dr Herman said.
When the reductions in costs and the costs of the interventions were factored, metformin saved $30 per person over the 20 years, whereas intensive lifestyle intervention cost $1500 per person. The lifestyle intervention was costlier to implement, because of greater use of resources, Dr Herman said, but it improved quality of life more than either metformin or placebo.
In the cost-utility analysis, lifestyle intervention cost $12,000 per quality-adjusted life-year gained, whereas metformin was cost-saving. “Only about 1 in 10 interventions in medicine are cost-saving,” he said.
Examples of other cost-saving interventions include prenatal care and pediatric immunization. “This puts metformin in the same category as these types of interventions,” he said.
The cost per quality-adjusted life-year saved with intensive lifestyle intervention to prevent diabetes is comparable to the costs of instituting beta-blocker therapy after myocardial infarction, statin therapy for secondary prevention of cardiac events, and antihypertensive drug treatment for persons with diastolic blood pressure >105 mm Hg, all of which are accepted as cost-effective interventions, he added.
“The message is very straightforward with metformin—less money was spent and people felt better with metformin,” Dr Herman said. “Metformin could revolutionize the way we approach diabetes prevention.” Health policy should also adopt the implementation of lifestyle intervention, he said, which can be made even less expensive while preserving effectiveness with group intervention.