Gaps in treatment, treatment resumption, and cost sharing.

Objectives: To describe the rate of return to statin therapy after an observed stoppage and to examine whether patient cost sharing plays a role in the resumption of therapy. Study Design: We conducted a retrospective, observational study of a cohort of commercially insured patients with a treatment gap in statin therapy. Methods: The 2006 to 2009 prescription drug and medical claims experience of individuals aged 18 to 64 years who filled at least 2 statin prescriptions was included. Treatment gaps were defined as at least 90 days without statin medications. To analyze the association between cost sharing and filling behavior within 1 year of discontinuation we estimated an alternative-specific conditional logit model, including cost-sharing prices faced for alternatives (brand, generic, no fill). Models controlled for sociodemographic characteristics, health status, and time. Results: Nearly half (42.5%) of patients with at least a 90-day gap in statin therapy did not return to treatment within the next year. Patients discontinuing branded statins were more likely to return to treatment (61.6%) than patients discontinuing generic statins (54.4%) (P