Glaucoma medication persistence with a fixed combination versus multiple bottles

Abstract

Objective:

To determine if prescribing combination therapy versus two or three separate bottles results in greater persistence among patients with glaucoma.

Methods:

Using a retail pharmacy claims database, three glaucoma patient cohorts were defined and followed for 12 months (January 2004 through December 2004). Patients in cohort 1 had a prescription for a single fixed-combination therapy during the month of January 2004. Cohort 2 consisted of patients with prescriptions for a β-blocker and one other glaucoma product in the same month. Cohort 3 comprised patients with prescriptions filled for three different glaucoma therapies during the first month. A fixed-combination formulation may have been included in cohorts 2 and 3 as well, but was counted as a single bottle. Persistence rate, defined as the percentage of patients who did not discontinue their medication over the 12-month period, was calculated.

Results:

Cohort 1 (one bottle; n = 14 742) was more persistent than cohort 2 (two bottles; n = 18 411), with 35.3% vs. 27.2% of patients remaining on therapy at the end of the study period (p < 0.0001). Cohort 3 (n = 4826), with three separate bottles per patient, had the lowest percentage remaining on therapy (23.9%; p < 0.0001).

Conclusion:

Analyses of pharmacy database data are limited by the possibilities of misidentifying newly treated patients or misclassifying added versus switched medications. As the number of separate products used for glaucoma therapy increases, patient persistence decreases. A management regimen requiring as few products as possible may enhance glaucoma patient persistence.

Key words: :

• Combination drug therapy
• Drug combinations
• Patient compliance

Transparency

Declaration of funding

This study was sponsored by Allergan, Inc., Irvine, CA, USA.

Declaration of financial/other relationships

J.H., E.J.D. and J.G.W. have disclosed that they are employees of Allergan, and A.G. has disclosed that she was a paid consultant. E.H. has disclosed that she has received honoraria for speaking and has participated in clinical trials funded by Allergan. She also has disclosed that she is a paid consultant for Pfizer, Allergan and Alcon.

Some peer reviewers receive honoraria from CMRO for their review work. Peer reviewer 1 of this paper has disclosed that he/she has served as advisor for Glaukos Corporation, Laguna Hills, CA, USA. The other reviewer has no relevant financial relationships.

Acknowledgment

The authors have disclosed that they had no outside editorial assistance in preparing this manuscript.

Preliminary reports of this study were presented at the annual meeting of the American Glaucoma Society, March 1–4, 2007, San Francisco, CA, USA; at the 8th annual meeting of the European Glaucoma Society, June 1–6, 2008, Berlin, Germany; and at the World Ophthalmology Congress, June 28 – July 2, 2008, Hong Kong, China.