Elsevier

Ophthalmology

Volume 116, Issue 2, February 2009, Pages 191-199
Ophthalmology

Original article
Adherence with Topical Glaucoma Medication Monitored Electronically: The Travatan Dosing Aid Study

Presented at: American Glaucoma Society Annual Meeting, March 2008, Washington, DC
https://doi.org/10.1016/j.ophtha.2008.09.004Get rights and content

Purpose

To assess patient adherence and behaviors with topical once-daily therapy for glaucoma.

Design

Prospective, observational cohort study.

Participants

One hundred ninety-six patients with glaucoma who were being treated with a prostaglandin analog in 1 or both eyes at the Scheie or Wilmer Eye Institutes between August 2006 and June 2007.

Methods

Detailed medical history was obtained from each patient. All subjects used the Travatan Dosing Aid (DA; Alcon, Fort Worth, TX) to administer travoprost as prescribed. Devices were collected at 3 months and the data of drop usage was downloaded using software provided with the dosing aid. Data were analyzed for the 8-week period starting 2 weeks after the enrollment visit and ending 2 weeks before the 3-month visit.

Main Outcome Measures

Assessment of adherence and patterns of drop usage as indicated by the DA.

Results

A total of 282 subjects consented to be in the study and 86 (30%) withdrew before study completion or had device errors, leaving 196 subjects (70%) with evaluable data at 3 months. The overall mean (±standard deviation) adherence rate was 0.71 (±0.24), ranging from 0.02 to 0.97. One hundred nine of these patients (55.6%) took greater than 75% of the expected doses. Those with adherence of less than 50% of expected doses showed substantially increased dose taking immediately after the office visit and just before the return visit at 3 months (P = 0.03). The mean adherence rate estimates of the physician and patient self-report were 0.77 and 0.95, respectively. The agreement between the physician assessment and DA-recorded adherence rate showed poor correlation for individual cases (intraclass correlation coefficient, 0.09; 95% confidence interval, 0.00–0.19).

Conclusions

Nearly 45% of patients using an electronic monitoring device who knew they were being monitored and were provided free medication used their drops less than 75% of the time. Patients reported far higher medication use than their actual behavior. The ability of the physician to identify which persons are poorly adherent from their self-report or from other subjective clues is poor.

Financial Disclosure(s)

Proprietary or commercial disclosure may be found after the references.

Section snippets

Study Organization

The study protocol had 2 phases: phase 1 was a prospective, observational cohort study of patient adherence to travoprost therapy when using the DA to administer drops (described in this article); phase 2 was a randomized, controlled trial to improve adherence for those found to have low adherence in phase 1 (subject of a subsequent report). Patients were recruited from the Glaucoma Services of the Wilmer Eye Institute and the Scheie Eye Institute. Institutional review boards at both centers

Results

Study recruitment began in August 2006 and ended in June 2007. A total of 282 patients were identified between the 2 sites; 86 (30%) withdrew before 3 months, leaving 196 subjects (70%) with complete data on drop-taking behavior at 3 months. The reasons why 30% of patients did not complete the study included: side effects (n = 33/86 [38%]), use of travoprost without the DA device (n = 15/86 [17%]), lost to follow-up (n = 12/86 [14%]), patient report that DA device interferes with using drops (n

Discussion

It has been hypothesized and reported that medication adherence would be improved by a simpler drug regimen.25, 26, 27, 28, 29 By contrast, the authors found that once-daily prostaglandin adherence was not substantially better than previously reported drop taking with β-blockers twice daily or pilocarpine 4 times daily.13, 14 After 3 months of electronic monitoring with the DA, the mean adherence rate for travoprost was 71% in the current cohort of patients. Kass et al13, 14 used an electronic

Acknowledgments

The authors thank Sameer Ahmed, MD, who helped with patient recruitment; Lei Zhang, MS, and Maureen Maguire, PhD, who contributed statistical assistance; and Stacy Boxley, COA, and Vanessa Kellner, BA, who provided patient enrollment and protocol support.

References (39)

  • D. De Amici et al.

    Impact of the Hawthorne effect in a longitudinal clinical study: the case of anesthesia

    Control Clin Trials

    (2000)
  • M.A. Kass et al.

    Can ophthalmologists correctly identify patients defaulting from pilocarpine therapy?

    Am J Ophthalmol

    (1986)
  • The Advanced Glaucoma Intervention Study (AGIS): 7The relationship between control of intraocular pressure and visual field deterioration

    Am J Ophthalmol

    (2000)
  • A. Heijl et al.

    Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial

    Arch Ophthalmol

    (2002)
  • D.R. Anderson

    Collaborative normal tension glaucoma study

    Curr Opin Ophthalmol

    (2003)
  • M.A. Kass et al.

    The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma

    Arch Ophthalmol

    (2002)
  • The Glaucoma Laser Trial (GLT) and Glaucoma Laser Trial follow-up study: 7Results

    Am J Ophthalmol

    (1995)
  • D.S. Friedman et al.

    Using pharmacy claims data to study adherence to glaucoma medications: methodology and findings of the Glaucoma Adherence and Persistency Study (GAPS)

    Invest Ophthalmol Vis Sci

    (2007)
  • B.L. Nordstrom et al.

    Persistence and adherence with topical glaucoma therapy

    Am J Ophthalmol

    (2005)
  • Cited by (0)

    Manuscript no. 2008-469.

    Available online: December 12, 2008.

    Financial Disclosure(s): The author(s) have made the following disclosure(s):

    David S. Friedman - Consultant, Honoraria, Research Support - Alcon.

    Harry A. Quigley - Consultant, Honoraria, Research Support - Alcon.

    No conflicting relationship exists for any other authors.

    Supported in part by the National Institutes of Health, Bethesda, Maryland (PHS research grants nos.: EY01765 [Core Facility Grant, Wilmer Institute], NIH K12 EY015398 [Dr Okeke]); a grant from The Paul & Evanina Bell Mackall Foundation Trust, New York, NY (Dr Okeke); and by an unrestricted gift from Alcon, Inc., Fort Worth, Texas.

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