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Glaucoma Factors Influencing Glaucoma Treatment Adherence Anand Mantravadi, 1 MD and Leslie Jay Katz, MD 2 1. Assistant Professor, Jefferson Medical College, Philadelphia, US; 2. Professor, Jefferson Medical College and Director, Glaucoma Service, Wills Eye Institute, Philadelphia, US Abstract Despite the availability of effective medical therapies, poor adherence to glaucoma medications is a significant challenge in the management of the disease. The basis for non-adherence is probably a complex interplay of many potential causes that can vary between different patient populations. Studies vary in the way adherence is measured, in the root causes of non-adherence, and in the possible ways to improve it. However, the overarching commonalities of these studies is the underlying reality that poor adherence is a major problem affecting the quality of glaucoma care. Awareness and detection of non-adherence by clinicians is also problematic. Adherence is often inaccurately thought of as a responsibility that rests entirely with the patient. However, identifying potential barriers to adherence, and implementing techniques and strategies to overcome these barriers, can begin to set the stage for improvement. Keywords Adherence, persistence, glaucoma, medications Disclosure: The authors have no proprietary or commercial interests in the topic. Anand Mantravadi, MD, has served as a consultant for Glaukos Co and as a speaker for Allergan. Leslie Jay Katz, MD, has served as a consultant and/or speaker for Glaukos Co., Allergan, and Alcon. Received: August 8, 2011 Accepted: December 8, 2011 Citation: US Ophthalmic Review, 2012;5(2):88–90 Correspondence: Leslie Jay Katz, MD, Wills Eye Institute, 840 Walnut Street, Suite 1110, Philadelphia, PA 19107, US. E: In the treatment of any chronic disease, even the most effective medical therapies cannot achieve optimal success without patients’ co-operation with their prescribed regimens. Patient behaviors, outlooks, and circumstances that lead them to not take prescribed medications are still poorly understood. Such behaviors are probably the result of a complex interplay of many factors that are not easily generalized. What has been commonly referred to as patient compliance can be more accurately described as adherence—the degree to which a patient follows the instructions to take a prescribed treatment during a defined period of time. 1 Persistence represents a measure of the time until the patient first discontinues a medication. 1 Patient adherence and persistence represent a pervasive problem in the care of patients with glaucoma. Although glaucoma is a major cause of blindness worldwide, the typical course of the disease—a chronic process that is initially asymptomatic—appears to set the stage for suboptimal patient adherence and persistence. Patients with glaucoma are largely not reminded by the disease process itself of the importance of taking medications as prescribed. Indeed, in the care of patients with glaucoma, adherence and persistence rates are not as good as one would hope. And poor adherence to medications can lead to worsening disease. 2,3 Moreover, ophthalmologists are not great detectors of non-adherence, with one large study finding that approximately one-fifth of patients had non-adherence undetectable by their physician. 4,5 Thus, non-adherence represents a major obstacle in the effective treatment of this sight-threatening condition. An emerging body of evidence examining factors that influence adherence is providing greater insight into the complexities surrounding why patients 88 have difficulty with adhering to glaucoma therapy and why doctors are poor at detecting this. In this article, we review methods of measuring adherence and persistence, and discuss some of the predominant barriers to adherence and possible strategies to improve it. Measuring Adherence and Persistence How does one really know whether a patient is taking a medication as prescribed? Detection of adherence in the clinical setting most commonly uses patient self-reporting in some form or another. When determining adherence in larger cohorts, self-reporting through interviews or questionnaires is a simple method, but also one that has several weaknesses. Self-reports are affected by selection bias and recall bias, and will reflect only the patients who submit to them. 2 Those who fail to attend follow-up appointments are excluded from such measurements. 2 Several studies have found that patients tend to overestimate their own adherence to treatment. 2,6–9 Rates of adherence across a variety of studies using self-reported figures range from 24 to 98  %. 2 This broad range—from dismally low to unexpectedly high adherence—reflects the probable inaccuracies of self-reporting in determining adherence rates. Electronic measurements of adherence, which use a device to count the drops coming out of the bottle, might circumvent recall bias but cannot certify whether or not a drop was actually instilled into a patient’s eye. 2 For most glaucoma medications, electronic devices are not readily available, and rates gleaned from studies using electronic measures thus have limited value in determining adherence rates in a broader sense. © TOUCH BRIEFINGS 2012