Use of COX-2-selective inhibitors decreased and the use of generic NSAIDs increased as formularies incorporated drug tiers, according to a study in the Archives of Internal Medicine. Enrollees in three-tier plans with arthritis and gastrointestinal comorbidities were significantly less likely to use COX-2-selective inhibitors than were patients in nontiered plans.
"Previously there had been the belief that a tiered copayment arrangement affected only whether medications were given at the generic level or brand level. But this paper showed that even among brand-name drugs, when the higher cost brands are pushed to the third level, patients don't have access to them," says Becky Briesacher, PhD, the lead investigator of the study.
The investigators found that selection of generic NSAIDs and of COX-2-selective inhibitors tends to follow copayment structure, but use of brand name NSAIDs does not. Use of COX-2-selective inhibitors decreased with two-tier coverage, while generic use increased. Forty-two percent of patients in three-tier formulary coverage selected COX-2s; 56 percent selected generic NSAIDs. Branded NSAID use remained relatively stable.
Tiered formularies that have additional incentives for preferred medications could create the potential for therapeutic compromises, according to the authors.
"There's a concern that if you put medications that people need up in the third tier, they may not get them," says Briesacher.
SOURCE: THREE-TIERED COPAYMENT DRUG COVERAGE AND USE OF NONSTEROIDAL ANTI-INFLAMMATORY DRUGS. ARCH INTERN MED. 2004; 164:1679-1684.