Raising copayments in tiered prescription drug plans increases the likelihood that patients will stop taking prescribed medications, according to a recent study published in the New England Journal of Medicine. The study followed two employers as they changed their prescription coverage plans in 2000. Employer A switched from a plan without tiers to a three-tier plan. The new health plan also increased all copayments for medications. Employer B switched employees from a two-tier to a three-tier formulary and increased copayments for the third tier only. The researchers identified two comparison groups with plans similar to those of employers A and B; these groups were not affected by the policy changes. This controlled for trends in drug utilization that were unrelated to formulary changes.
More patients in the Employer A group stopped taking their medications than in the comparison group. Switching to lower-tiered alternatives was also more prevalent in Employer A's population than in the comparison group.
"All the evidence is not in yet," says Richard G. Frank, PhD, in the department of health care policy at Harvard Medical School, a coinvestigator on the study. "But no clinician has told me there's a whole lot of difference between switching from one PPI to another. What is troubling is when patients stop taking their medication."
Employer B's members were more likely to switch from a nonpreferred brand to a less expensive brand or generic. Employees in this plan did not show a significant change in compliance or spending.
SOURCE: THE EFFECT OF INCENTIVE-BASED FORMULARIES ON PRESCRIPTION DRUG UTILIZATION AND SPENDING. DEPARTMENT OF HEALTH CARE POLICY, HARVARD MEDICAL SCHOOL