Noncompliance in Glaucoma

Noncompliance with therapy forms a major obstacle to the successful management of chronic diseases such as glaucoma, diabetes, and systemic hypertension. Studies of patients' behavior have revealed that only 25% to 59% follow their physicians' instructions,^1,2 and approximately 10% of glaucoma-related blindness may be due patients' not adhering to medical therapy.³ The reasons volunteered by patients with glaucoma for their poor compliance include forgetfulness,^1-4 inconvenience,^1,5 a daily-dose frequency,¹ difficulty obtaining a doctor's appointment,^2,4 not considering their disease to be serious,² the waiting time in the clinic,² an inability to instill eye drops,⁵ the side effects of their medications,¹ confusion regarding dosing instructions,² fear,² a lack of insurance,² “too many” medications, the cost of therapy,¹ no improvement of visual symptoms,^1,2 a lack of transportation,² and the exhaustion of their supply of medications.¹

Compounding the problem is clinicians' frequent failure to detect their patients' noncompliance or to understand how patients' perceptions and social context influence their behavior. The aim of our prospective study was to identify factors (including demographics, severity of glaucoma, types of antiglaucoma drugs, patients' psychology, socioeconomics, and physical disabilities [eg, arthritis, blindness, tremors]) that may be associated with patients' poor adherence to therapy. This information may enable clinicians to combat noncompliance and treat their patients more successfully.

METHODS AND MATERIALS
For this study, we defined noncompliance as a patient's tendency to miss two or more doses of prescribed medications per week, their voluntary admission of noncompliance, or their tendency regularly to miss follow-up visits. One hundred ten patients with primary open-angle glaucoma and ocular hypertension were enrolled at random from a university-based eye clinic and a county hospital in Dallas.

We characterized visual field defects as mild (confined to one quadrant), moderate (involving two quadrants), or severe (involving greater than or equal to three quadrants). On the day of their visit, we personally interviewed patients and administered a 36-item questionnaire. The information gathered included patients' age, race, gender, and visual acuity; the severity of their visual field defects; a history of hypertension, diabetes, and/or myopia; their average annual household income; their educational level; the glaucoma medications used; their reasons for compliance and noncompliance; their understanding of glaucomatous disease; and the level of their concern about their glaucoma. Seventy-seven of the patients complied with their medical therapy, and 33 did not. Table 1 shows the demographic features of these two groups and some relevant variables. We employed a chi-squared test to compare the features of the two groups and considered P<.05 significant.

RESULTS
Level of Education
Educational level appeared to significantly influence noncompliance. Fourteen of 19 (73.7%) noncompliant versus 20 of 52 (38.5%) compliant patients (P=.04) had a maximum education level of high school or less (n = 53 for compliant patients, n = 19 for noncompliant patients). Of patients with more than a high school education, 61.5% complied with prescribed medical therapy, as compared with 26.3% who did not (P=.04).

Level of Concern
The second main factor in patients' compliance or noncompliance with medical therapy was their level of concern about their disease. We divided subjects into five categories: 1 = appropriate (asks appropriate questions about his disease); 2 = excessive (asks too many questions, overly concerned); 3 = passive (asks few questions and expects physicians to make all medical decisions); 4 = no concern (not serious about treatment and misses many appointments); and 5 = denial (does not acknowledge having glaucomatous disease).

Thirteen (39.4%) noncompliant patients were passive as compared with 19 (24.7%) compliant patients (P=.002). Their most common reasons for missing the medications were forgetfulness (42.4%), being “too busy” (15.15%), drug side effects (12.12%), a lack of funds (9.00%), running out of the medications (9.00%), and missing appointments (3.10%). Noncompliant individuals were more likely than compliant patients to miss follow-up visits (27.3% vs 7.8%, respectively [P=.002]).

The average follow-up visits occurred 4 to 6 months apart in both groups. We determined that noncompliant patients missed 21.2 days of treatment between visits, whereas compliant patients missed 5 days. There were no differences between the two subject groups in terms of their gender, race, household income, number of prescribed medications, or basic understanding of the known risk factors for glaucoma, including elevated IOP, diabetes, hypertension, family history of glaucoma, and race.

DISCUSSION
Although noncompliance is a serious problem in glaucoma management, we as a field lack a standard definition for this term.^1-6 Investigators have assessed noncompliance by directly asking patients about their nonadherence to therapy,¹ calculating the number of missed follow-up visits per year,² employing devices that check the number of times a bottle is opened,⁴ or determining which prescriptions were unfilled.⁷ When defining noncompliance, we took into account whether patients missed two or more of their prescribed doses per week,⁸ voluntarily admitted their nonadherence to therapy, and/or had an erratic history of keeping follow-up visits. Our aim was to maximize our detection of noncompliant individuals.

The two most significant factors associated with noncompliance were a lower level of education (less than or equal to that of high school) and a passive attitude about the disease. It could be argued that lower levels of education result in lower-paying jobs and an inability to pay for expensive drug therapy. Another issue is that patients who have a high school education or less may find it difficult to understand the implications of their glaucoma for themselves and their families.

As in other studies,^1-3,7,9,10 we found that noncompliant patients were more likely than compliant patients to miss follow-up visits (27.3% vs 7.8%, P=.002).

CONCLUSION
Addressing the serious problem of noncompliance entails better educating patients and tailoring their therapy. Not all compliant patients follow instructions all the time, and not all noncompliant patients consistently fail to follow instructions. Physicians should question their patients at every visit about whether they have experienced drug side effects, undergone changes in their general health, or have concerns about their glaucoma and therapy. If drug costs are an issue, prescribing a less expensive agent is advisable, particularly for patients with a maximum educational level of high school or less. These individuals may be embarrassed to acknowledge problems with the costs of their treatment or poor comprehension of their disease. By spending time with patients to discover and discuss their concerns, physicians may achieve far better rates of compliance.

This study was supported in part by an unrestricted research grant from Research to Prevent Blindness, Inc., in New York.

Karanjit S. Kooner, MD, MBA, is an associate professor at the Department of Ophthalmology, UT Southwestern Medical Center. Dr. Kooner may be reached at (214) 648-4733; kjkooner@yahoo.com.

Joel Aronowicz, MD, is a glaucoma fellow at the Department of Ophthalmology, UT Southwestern Medical Center. Dr. Aronowicz may be reached at joel.aronowicz@utsouthwestern.edu.

1. Patel SG, Spaeth GL. Compliance in patients prescribed eye drops for glaucoma. Ophth Surg. 1995;26:233-236.
2. Kosoko O, Quigley HA, Vitale S, et al. Risk factors for noncompliance with glaucoma follow-up visits in a resident's eye clinic. Ophthalmology. 1998;105:2105-2111.
3. Ashburn F, Goldberg I, Kass M. Compliance with ocular therapy. Surv Ophthalmol. 1980;24:237-246.
4. Taylor SA, Galbraith SM, Mills RP. Causes of non-compliance with drug regimen in glaucoma patients: a qualitative study. J Ocul Pharmacol Ther. 2002;18:401-409.
5. Winfield AJ, Jessiman D, Williams A, et al. A study of the causes of non-compliance by patients prescribed eyedrops. Br J Ophthalmol. 1990;74:477-480.
6. Kass MA, Meltzer DW, Gordon MO. The compliance factor. In: Drance SM, Neufeld AH, eds. Glaucoma: Applied Pharmacology in Medical Treatment. Orlando, Florida: Grune & Stratton; 1984:537-568.
7. Gurwitz JH, Yeomans SM, Glynn RJ, et al. Patient noncompliance in the managed care setting. Med Care. 1998;36:357-369.
8. Konstas AGP, Maskaleris G, Gratsonidis S. Compliance and viewpoint of glaucoma patients in Greece. Eye. 2000;14:752-756.
9. Gurvitz JH, Glynn RJ, Monane M, et al. Treatment for glaucoma: adherence by the elderly. Am J Public Health. 1993;83:711-716.
10. Lee MD, Fechtner FR, Fiscella RG, et al. Emerging perspectives on glaucoma: highlights of a round table discussion. Am J Ophthalmol. 2000;130(suppl):1-11.