LONG BEACH, CALIF. — Modest reductions in medication copayments can encourage patients with diabetes to fill their prescriptions and use their drugs, according to researchers at the University of Michigan.
As part of the Michigan Healthy Communities Initiative, the university chose to test a concept called “value-based benefit design.” According to this concept, cost sharing is based not just on the acquisition cost of medication, but also on the likelihood of benefit, Dr. William Herman explained at a diabetes meeting sponsored by the Centers for Disease Control and Prevention. The greater the benefit to the patient, the lower would be his or her copayment.
“Value-based benefit design provides a financial incentive, therefore, to targeted patients to use therapies from which they are most likely to benefit,” said Dr. Herman of the university, in Ann Arbor.
To test this concept, 1,777 university employees and dependents with diabetes were identified and offered copayment reductions on antihyperglycemics, antihypertensives, antihyperlipidemics, and antidepressants.
The price of tier 1 generic medications was reduced 100%, from $7 to zero; the price of tier 2 preferred brand medications was reduced 50%, from $14 to $7; and the price of tier 3 nonpreferred brand medications was reduced 25%, from $24 to $18.
As a control group, investigators identified 3,273 patients with diabetes from the same health plan but with employers other than the University of Michigan. These patients were not offered this reduction in copayments.
Over a 2-year period, patients in the intervention group filled significantly more prescriptions in all medication groups than did those in the control group. For example, there was a 3% absolute increase in filled metformin prescriptions and a 5% absolute increase in filled statin prescriptions.
The investigators measured adherence using a metric called the medication possession ratio (MPR), defined as the amount of medication filled divided by the amount needed to fill to take as prescribed.
Investigators saw a statistically significant 7% absolute increase in MPR for ACE inhibitors and angiotensin II receptor blockers. There was also a 4% absolute increase in the MPR for statins, but that did not reach statistical significance. There were no significant changes in MPR for metformin or SSRIs.
The investigators were concerned that reductions in copayments across the board might encourage use of the more expensive tier 2 and tier 3 medications, but that did not happen. Use of tier 2 medications actually decreased from about 30% to about 15% of all claims, while the use of generic medications increased from 65% to 80%.
In all, the health system granted copayment relief for 86,655 claims, at a cost of $869,767 over 2 years. Antihypertensives represented 36% of this, antihyperglycemics represented 35%, antihyperlipidemics 19%, and antidepressants 10%.
Almost three-quarters (74%) of the copayment relief went for tier 1 medications; 21% went to tier 2 and 5% to tier 3.
“We concluded that value-based benefit design is a useful adjunct to interventions designed to increase patient initiation of and adherence to evidence-based medications,” Dr. Herman said.
Dr. Herman did not report any conflicts of interest related to his presentation. Dr. Herman is the Stefan S. Fajans/GlaxoSmithKline Professor of Diabetes at the University of Michigan.
Use of more expensive tier 2 medications actually decreased from 30% to 15% of all claims. DR. HERMAN