Consumer cost sharing and use of biopharmaceuticals for rheumatoid arthritis

To evaluate the effect of consumer cost sharing on use of physician-administered and patient self-administered specialty drugs for rheumatoid arthritis.

Multivariate statistical analysis of probability and use of physician-administered specialty drugs, patient self-injected specialty drugs, non-biologic disease-modifying anti-rheumatic drugs, and symptom relief drugs. Analyses were conducted for patients enrolling in preferred provider organization (PPO) plans and health maintenance organization (HMO) plans with different cost-sharing requirements, adjusted for patient demographics, health status, and geographical location.

Professional, facility, and pharmaceutical claims for beneficiaries of CalPERS, the public employee insurance purchasing alliance in California, for 2008-2009. Consumer cost-sharing requirements were obtained for each type of drug and service for each type of insurance plan.

PPO insurance enrollees face substantially higher cost sharing for physician-administered specialty drugs, compared with HMO enrollees in CalPERS. PPO patients with rheumatoid arthritis are only half as likely as HMO enrollees to choose a physician-administered specialty drug (4.2% vs 9.3%) (P ≤.05), and use 25% less of the drugs if they use any ($10,356 vs $13,678) (P ≤.05). They are 30% more likely to use a self-administered specialty drug than are HMO enrollees (29.3% vs 22.1%) (P ≤.05), and use 35% more of the drugs if any ($16,015 vs $12,378) (P ≤.05).

Consumer cost sharing reduces the use of physician-administered specialty drugs for rheumatoid arthritis. The higher use of patient self-administered specialty drugs suggests that the disincentives for use of physician-administered drugs were offset by an increased incentive to use self-administered drugs.