Sofosbuvir initial therapy abandonment and manufacturer coupons in a commercially insured population

To describe rates of sofosbuvir initial medication adherence as a function of the insurer-required member cost (ie, out-of-pocket cost) and to determine how manufacturer coupons affect insurer-required member cost.

Observational cross-sectional analysis.

Administrative pharmacy claims data from 13 million commercially insured members were used to identify sofosbuvir new starts between January 2014 and September 2014. Members were categorized as either sofosbuvir initial adherence or as abandoning therapy. A multivariate logistic regression model adjusting for sociodemographic characteristics, severity of illness, and total drug costs (health insurer plus member amount) for non-sofosbuvir pharmacy claims in 2014 was used to evaluate the association between insurer-required member cost and initial medication adherence. In a sub-analysis, sofosbuvir index claims with coupon data available were analyzed to determine how coupon use impacted insurer-required member cost.

A total of 67.3% of members had a pre-coupon member cost of < $250 for their index sofosbuvir claim. Just 201 (5.0%) members were exposed to a member cost of more than $10,000. The logistic regression model demonstrated an association between member cost and abandonment starting at $2500 to < $5000 (odds ratio: 1.9; 95% CI, 1.01-3.43; P = .0393). The average member sofosbuvir index claim cost was $1349 before coupon was applied, and $28 after. Overall, coupons offset the member amounts paid by 98%: $771,593 of the $787,860 member cost requested by the insurer.

These findings indicate that a 30-day supply sofosbuvir member cost of > $2500 was associated with increased initial therapy abandonment, and that manufacturer coupons substantially reduced sofosbuvir insurer-required member cost. Insurers and policy makers should consider the impact of member cost on medication adherence and the impact coupons have on the actual member cost.