The findings showed that
• High-cost enrollees in the capped plan discontinued medication at higher rates than patients in the uncapped plan (see figure) across all the classes of drugs.
• Rates of discontinuation between the two plans diverged in the latter part of each year as more enrollees in the capped plan reached the limit. By December of each year, this divergence reached its highest level. Use of antihypertensives, antidepressants, antidiabetics, and cholesterol-lowering drugs was 15 to 28 percent lower among members of the capped plan. Reductions in use were even greater for the two classes of drugs with broadly available over-the-counter substitutes — anti-inflammatories and antiulcerants.
• The drug classes with the greatest differences in discontinuation rates were antihypertensives (22 percent compared with 14 percent under the uncapped plan) and cardiac drugs (28 percent compared with 19 percent under the uncapped plan).
• Enrollees in the $2,500-cap plan also reinitiated drug use at higher rates when benefits resumed, suggesting that decisions to discontinue were strongly influenced by the benefit limit.
A Systematic Review of the Adverse Effects of Prescription Drug Cost Sharing
Pharmacy Benefit Caps and the Chronically Ill
Source: Geoffrey F. Joyce, Dana P. Goldman, Pinar Karaca-Mandic and Yuhui Zheng Health Affairs, Vol. 26, No. 5, September 2007 (subscription required)