Preventing diabetes with metformin is cost saving, while lifestyle intervention is also cost effective

Lifestyle intervention is cost effective, and metformin therapy is actually cost saving in the prevention of type 2 diabetes, said William H Herman, MD, MPH. These economic data were derived from a 10-year cost analysis as a follow-up to the landmark Diabetes Prevention Program (DPP).
     The DPP showed that overweight and obese persons older than 35 years with impaired glucose tolerance who were assigned to lifestyle intervention had a 58% reduction in the development of diabetes compared with controls, and metformin was associated with a 31% reduction compared with placebo. 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, and metformin-treated patients were encouraged to continue with metformin, and follow-up continued for an additional 7 years.
     The intervention costs were calculated, and a cost-utility analysis was performed. Treatment with metformin or lifestyle intervention reduced the cost of medical care by $1700 and $2600 per person, respectively, over 10 years compared with placebo. The reduction in cost came from fewer outpatient visits, fewer hospitalizations, and reduced drug costs in the intervention groups as they forestalled or prevented incident diabetes, said Herman, Professor of Medicine and Epidemiology at the University of Michigan, Ann Arbor.
     When the reductions in costs and the costs of the interventions were factored, metformin actually saved $30 per person over the 10 years while the lifestyle intervention cost $1500 per person. The lifestyle intervention was costlier to implement owing to greater use of resources, he said.
     In the cost utility analysis, lifestyle intervention cost $12,000 per quality life-year gained, while metformin was cost saving. “Only about 1 in 10 interventions in medicine are cost-saving,” said Herman. Others are prenatal care and pediatric immunization.
     The cost per quality life-year saved with lifestyle intervention to prevent diabetes is comparable to the costs of instituting beta blockers after myocardial infarction, statins for secondary prevention of cardiac events, and antihypertensive drug treatment for persons with diastolic blood pressure greater than 105 mmHg, 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,” said Herman. “Metformin could revolutionize the way we approach diabetes prevention.” Health policy should also adopt implementation of lifestyle intervention, he said, which can be made even less expensive while preserving effectiveness with group intervention.