Glaucoma Medication Reminders May Improve Adherence

Laird Harrison

September 04, 2015

Patients with glaucoma have better medication adherence when they have more eye care appointments and lower drug copayments, a new study shows.

The findings suggest ways healthcare providers could improve adherence to glaucoma prescriptions, Paula Anne Newman-Casey, MD, told Medscape Medical News.

"If we can increase people's contact with the healthcare system in new ways — it doesn't necessarily have to be with the doctor, it could be a health educator — we could impact the disease," she said.

Dr Newman-Casey, an assistant professor at the University of Michigan Department of Ophthalmology and Visual Sciences in Ann Arbor, and colleagues published their findings online August 24 in Ophthalmology.

Previous studies have suggested that 30% to 80% of people with glaucoma do not take their medications as prescribed, but it is difficult for physicians to tell which patients are taking the drugs and which are not. Patients often overestimate the amount they are taking and tend to take the medications just before seeing their physicians.

To get a better idea of which patients are most likely to miss doses, Dr Newman-Casey and colleagues analyzed data from Clinformatics DataMart, a database from a large managed care network. The database included procedures, office visits, prescriptions filled, and sociodemographics for 15,914,449 eye care beneficiaries throughout the United States.

The researchers focused on 1234 patients who were at least 40 years old and who were newly diagnosed and treated for open-angle glaucoma.

They measured adherence by dividing the number of days the patients had the correct amount of medication on hand by the number of days in the study period. The researchers identified five patterns of adherence: persistently good adherence, persistently moderate adherence, declining adherence, persistently very poor adherence, and never adherent.

The researchers calculated patterns during the first year and patterns over the course of 4 years.

Table. Patient Adherence

Adherence Year 1, % Year 4, %
Never adherent 7.5 15.6
Persistently very poor adherence 14.9 23.4
Declining adherence 9.5 9.1
Persistently moderate adherence 48.1 37.0
Persistently good adherence 20.0 15.0

They found that 49.7% of patients stayed in the same group for all 4 years.

Of those in the persistently good group during the first year, 93.9% stayed in that group or dropped to the persistently moderate group. Of those in the persistently moderate group, 63.4% remained in that group or improved to the persistently good group. And of those in the declining group, 94.9% went to the persistently very poor group.

In addition, 89.5% of those in the never-adherent or persistently very poor groups stayed in one of those groups.

The researchers next analyzed what factors correlated to the different types of adherence. Nonwhite people were 40% less likely to maintain good adherence, which was statistically significant (P = .02). In the 1-year analysis, patients in the persistently good adherence group were more likely to be older, to be white, and to have a higher first medication copayment cost (P < 0.05 for all comparisons). Patients in the never-adherent and declining adherence groups were more likely to report lower annual income (<$60,000) and get their prescriptions from a store pharmacy instead of mail-order or both mail-order and pharmacy (P < 0.02). These same sociodemographic characteristics were still significant in the 4-year analysis.

Those who made three visits to an eye care provider in the first year of follow-up were 1.8 times more likely to adhere than those who made fewer visits, and those who paid more for their prescriptions were less likely to adhere: Each additional dollar of copayment for an index prescription fill was correlated to a drop of 0.06% in the amount of time the patients had the correct prescription in their possession over the following 3 years. For example, a patient who paid $54 had the correct prescription on hand 2.9% less 3 years later than a patient who paid $6.

Healthcare providers cannot do much to affect the race or wealth of their patients, said Dr Newman-Casey, but they might be able to influence some of the other factors that affect adherence.

"We could increase people's contact with the healthcare system by embracing more team-based care, where the physician works with health educators to make sure patients really understand their disease," she said.

She suggested that glaucoma care might follow a model such as that used in diabetes: Both are diseases in which the patient is typically not bothered by symptoms, she pointed out. "Glaucoma is a similarly insidious condition, and we need a similar model of care," she said.

Also, physicians could consider cost, she suggested. "Physicians should consider whether a less expensive alternative is available for their patients, like a generic medication," she said. "Bringing up cost may be an embarrassing topic for patients, so it is important for physicians to bring it up as a possible issue."

Finally, she said, better use of electronic health records might allow physicians to see which patients are filling their prescriptions, which would allow the physicians to troubleshoot problems. Although some patients might see this as an invasion of privacy, she said, others assume physicians already have this information.

Susan J. Blalock, PhD, told Medscape Medical News that reasons for nonadherence might change over time. For example, someone might become ill and have difficulty taking a medication, said Dr Blalock, a professor of pharmacy at the University of North Carolina at Chapel Hill who has researched glaucoma medication adherence.

However, she agreed that physicians can help their patients better by taking the cost of prescriptions into consideration. "This is a very good suggestion," she said. "There is a whole literature on cost-related nonadherence."

This study was funded by American Glaucoma Society Mentoring for Advancement of Physician-Scientists, the National Eye Institute Michigan Vision Clinician-Scientist Development Program, and Research to Prevent Blindness. One coauthor was a past consultant for Genentech, Novartis, and the Centers for Disease Control and has stock in Pfizer, Merck, GlaxoSmithKline, Medco Health Solutions, and Vital Springs Health Technologies. The other authors and Dr Blalock have disclosed no relevant financial relationships.

Ophthalmology. Published online August 24, 2015. Abstract


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