Accounting for restart rates in evaluating persistence with ocular hypotensives

Abstract

Purpose: Persistence with ocular hypotensive medication is important as a long-term outcome, and rates of persistence typically are low. This study assessed restart rates for 3 prostaglandin analogs by determining the percentage of patients who discontinued and then restarted therapy.

Design: Retrospective cohort study of pharmacy claims submitted to a large national administrative claims database.

Participants: In all, 4356 patients initiating prostaglandin therapy were identified.

Methods: Claims for 3 prostaglandin analogs (bimatoprost, latanoprost, travoprost [index prostaglandin]) submitted between 2001 and 2002 were analyzed. Patients were excluded if they did not have coverage in the plan for the preceding 180 days or had been prescribed any ocular prostaglandin in the prior 180 days.

Main outcome measures: Persistence was defined as neither discontinuing nor changing the index prostaglandin. The number of current users of the index prostaglandin at day 180 was the sum of patients who persisted with the index prostaglandin plus patients who restarted the index prostaglandin after a discontinuation.

Results: Of the 4356 patients initiating prostaglandin therapy, 2503 (57%) were potential current users (were still plan members and had not switched ocular hypotensive therapies after 180 days). Just over half, (1356/2503 [54%]) were current users, including 879 (35%) who persisted with their index prostaglandin and 477 (19%) who restarted their index prostaglandin. Of patients discontinuing their index prostaglandin, more than half failed to restart any topical therapy (827/1624 [51%]).

Conclusions: Previous studies showing low persistence rates for glaucoma therapy failed to evaluate restarts. Restart analyses are crucial for assessing long-term treatment of chronic diseases such as glaucoma. In general, persistence remains a challenge, and our findings demonstrate the importance of clinicians' identifying patients who are not persistent and encouraging them either to restart or to initiate treatment with an alternative therapy.