Predicting Adherence With the Glaucoma Treatment Compliance Assessment Tool.

PRéCIS:: Univariate and multivariable models using the Glaucoma Treatment Compliance Assessment Tool (GTCAT) statements identified multiple, patient-specific factors associated with adherence that could be used to inform personalized interventions to optimize glaucoma adherence. PURPOSE: The purpose of this study was to determine the health behavior factors related to glaucoma adherence in patients with self-reported poor adherence. METHODS: A research coordinator used the Chang Adherence Measure and the Morisky Medication Adherence Scale to identify subjects with poor self-reported glaucoma medication adherence and enrolled them in a 3-month study to electronically monitor medication adherence. At enrollment, the coordinator administered the GTCAT. We calculated the percentage of prescribed doses taken over a 3-month period using an electronic dose monitor (AdhereTech). We used Rasch analysis, and univariate and multivariable regression to determine the GTCAT statements that predicted electronically monitored adherence. RESULTS: The mean adherence was 73.8% (SD=21.04%, range: 13% to 100%). Rasch analysis showed that the GTCAT had a good overall fit and no differential bias (Anderson likelihood ratio test >0.05). Multiple GTCAT statements were associated with adherence, which represented increased knowledge, increased cues-to-action, decreased barriers, less depression, and increased self-efficacy (P<0.09 for each). The full GTCAT or a subset of statements had a high association with adherence (R range: 0.44 to 0.51, P<0.005 for all). The GTCAT identified >50% of patients who wanted more education about glaucoma; >68% who did not use reminders; and >40% who reported having difficulty using the eye drops. CONCLUSIONS: The GTCAT identified multiple factors associated with adherence. Clinicians and researchers could use this tool to identify specific barriers to adherence and develop potential interventions to improve adherence.

Characteristics Associated with Adherence to Annual Dilated Eye Examinations among US Patients with Diagnosed Diabetes.

PURPOSE: To identify the characteristics that are associated with adherence to annual diabetic eye exams and patient awareness of retinopathy using a nationally representative sample from the United States. DESIGN: Cross-sectional, secondary analysis. PARTICIPANTS: National Health and Nutrition Examination Survey (NHANES) participants from 2005 to 2016 aged 20 years and older with diabetes mellitus. METHODS: The NHANES collected surveys every 2 years from 2005 to 2016, which contained demographic information, clinical information, and time to last dilated eye exam. From 2005 to 2008, retinal photographs were taken of all participants older than 40 years of age. We used univariate and multivariable logistic regression to determine the demographic and clinical factors associated with adherence to annual diabetic eye examinations and those associated with correctly reporting their retinopathy status. MAIN OUTCOME MEASURE: Factors associated with adherence defined as having an eye exam within the preceding 12 or 24 months. RESULTS: From 2005 to 2016, NHANES surveyed 4072 individuals who represent 20 million Americans aged 20 years and older with self-report of diabetes. By using the adherence definitions of 12 and 24 months, 63.4% and 78.7%, respectively, were adherent to diabetic eye examinations. The nonadherence rates of 36.6% and 21.3% for this national estimate did not change from 2005 to 2016 (P = 0.7, logistic regression). Insurance status, age, education, income, cholesterol levels, duration of diabetes, and self-reported retinopathy were all significantly associated with adherence with both definitions (all P < 0.05, logistic regression). Insurance status had the highest predictive value, with 76% of Americans on combination private-public insurance adherent compared with 36% of uninsured. Most Americans with retinopathy incorrectly denied having the diagnosis (2 727 144/3 896 093 or 70%). CONCLUSIONS: Multiple variables were associated with nonadherence to eye exams, with insurance status having the strongest association. Adherence with annual eye exams has not improved over the past decade. The majority of patients with retinopathy are unaware of this diagnosis, including the majority of those with a dilated funduscopic examination in the past year. Further improvements in education and adherence may reduce the visual morbidity caused by diabetes.

Psychometric Properties of the Reduced Version of the Glaucoma Treatment Compliance Assessment Tool (GTCAT).

PURPOSE: To measure the psychometric properties of a reduced, 27-statement version of the Glaucoma Treatment Compliance Assessment Tool (GTCAT). METHODS: We administered the GTCAT to 183 participants who were using a single bottle of an ocular hypotensive agent, and objectively measured adherence with Medication Event Monitoring System devices over 60 days. Adherence was the number of days with correctly timed bottle openings divided by the total number of study days. Using the 47-statement GTCAT, we created a reduced GTCAT by removing statements that: (1) did not load using Principal Components Analysis (PCA); (2) did not have a univariable association with adherence; or (3) were highly correlated (.75 or higher) with another statement. We assessed the construct validity of the remaining statements using PCA and assessed the predictive validity using multiple logistic regression analysis. RESULTS: We removed 20 statements because they did not appear in the PCA analysis; were not predictive of adherence; and/or had high correlation. PCA of the reduced GTCAT (27 statements) extracted 5 components of the Health Belief Model (knowledge, susceptibility, cues-to-action, self-efficacy, and barriers). Multiple regression showed that the 27 statements predicted adherence (Rsq = .11, p = .03). CONCLUSIONS: The reduced version of the GTCAT is associated with adherence, which suggests that after external validation, future glaucoma medication adherence studies could use the reduced version to efficiently measure health behaviors and determine the benefit of the GTCAT to develop personalized interventions in glaucoma adherence.

Psychometric Properties of the Glaucoma Treatment Compliance Assessment Tool (GTCAT) in a Brazilian Population.

PURPOSE: To determine the psychometric properties of a reduced version of the Glaucoma Treatment Compliance Assessment Tool (GTCAT), which was translated to Brazilian Portuguese. PATIENTS AND METHODS: We translated into Portuguese the GTCAT using validated techniques and administered it to a group of glaucoma patients using at least 1 ocular hypotensive eye drop medication. We used principal components analysis to determine construct validity, Rasch analysis, and Cronbach α for internal consistency reliability, frequency analysis for floor and ceiling effects, and Spearman ρ for test-retest reliability. RESULTS: We included 76 glaucoma patients. Principal component analysis loaded 14 questions into 7 components that were consistent with the Health Belief Model. The components were related to "barriers due to lack of drops," "self-efficacy," "experience of negative effects of the disease," "well-being," "general glaucoma knowledge," "glaucoma symptoms," and "cues-to-action." No statements had floor or ceiling effects, and all statements had acceptable test-retest reliability. Components had internal consistency Cronbach α reliability between 0.125 and 0.794. and average Spearman ρ reliability was 0.73, ranging from 0.44 to 1.00. According to Rasch analysis, the mean (±SD) of the person measures was 0.24±0.15 logits, person separation index was 0.58, and person reliability 0.25. CONCLUSIONS: The Portuguese-translated version of the GTCAT showed acceptable psychometric properties. With further refinement, clinicians and researchers could use it to better investigate glaucoma adherence issues in the Brazilian population.

Psychometric properties of the Glaucoma Treatment Compliance Assessment Tool in a multicenter trial.

PURPOSE: To assess the psychometric properties of a new version of the Glaucoma Treatment Compliance Assessment Tool, a survey evaluating health behavior and glaucoma adherence using constructs from the Health Belief Model. DESIGN: Psychometric analysis. METHODS: We administered the 47-statement Glaucoma Treatment Compliance Assessment Tool to 201 participants who were using a single bottle of an ocular hypotensive agent, and objectively measured adherence with medication event monitoring system devices over 60 days. Adherence was the percentage of days with correctly timed bottle openings. We used principal components analysis to determine construct validity, Cronbach's alpha for internal consistency reliability, frequency analysis for floor and ceiling effects, and Spearman rho for test-retest reliability. We determined predictive validity using univariate and multiple regression. RESULTS: The mean (±SD, range) adherence percentage was 79.9% (±18.5%, 20.3%-100.0%). Principal component analysis loaded 24 questions into 6 components that were consistent with the Health Belief Model. All 6 components had Cronbach's alpha reliability between 0.601 and 0.797. No statements had floor or ceiling effects, and all statements had acceptable test-retest reliability. Multiple regression analysis showed 4 Health Belief Model statements, white race, older age, and married marital status to be associated with higher adherence (adjusted R(2) = 0.27, P < .001). CONCLUSIONS: The newest version of the Glaucoma Treatment Compliance Assessment Tool showed acceptable psychometric properties. With further refinement, clinicians and researchers could use it to examine factors related to adherence and measure improvement in adherence with a change in health behavior attitudes.

Ocular hypertension: an approach to assessment and management.

Ocular hypertension is a common and important problem seen by eye care providers. This review presents a practical approach to individuals with ocular hypertension. It describes the common functional and structural investigations used in evaluation, as well as the advantages and disadvantages of each test. This review also discusses several landmark studies on ocular hypertension and provides a practical guide to the management of this problem.

Assessment of the reliability of standard automated perimetry in regions of glaucomatous damage.

PURPOSE: Visual field testing uses high-contrast stimuli in areas of severe visual field loss. However, retinal ganglion cells saturate with high-contrast stimuli, suggesting that the probability of detecting perimetric stimuli may not increase indefinitely as contrast increases. Driven by this concept, this study examines the lower limit of perimetric sensitivity for reliable testing by standard automated perimetry. DESIGN: Evaluation of a diagnostic test. PARTICIPANTS: A total of 34 participants with moderate to severe glaucoma; mean deviation at their last clinic visit averaged -10.90 dB (range, -20.94 to -3.38 dB). A total of 75 of the 136 locations tested had a perimetric sensitivity of ≤ 19 dB. METHODS: Frequency-of-seeing curves were constructed at 4 nonadjacent visual field locations by the Method of Constant Stimuli (MOCS), using 35 stimulus presentations at each of 7 contrasts. Locations were chosen a priori and included at least 2 with glaucomatous damage but a sensitivity of ≥ 6 dB. Cumulative Gaussian curves were fit to the data, first assuming a 5% false-negative rate and subsequently allowing the asymptotic maximum response probability to be a free parameter. MAIN OUTCOME MEASURES: The strength of the relation (R(2)) between perimetric sensitivity (mean of last 2 clinic visits) and MOCS sensitivity (from the experiment) for all locations with perimetric sensitivity within ± 4 dB of each selected value, at 0.5 dB intervals. RESULTS: Bins centered at sensitivities ≥ 19 dB always had R(2) >0.1. All bins centered at sensitivities ≤ 15 dB had R(2) <0.1, an indication that sensitivities are unreliable. No consistent conclusions could be drawn between 15 and 19 dB. At 57 of the 81 locations with perimetric sensitivity <19 dB, including 49 of the 63 locations ≤ 15 dB, the fitted asymptotic maximum response probability was <80%, consistent with the hypothesis of response saturation. At 29 of these locations the asymptotic maximum was <50%, and so contrast sensitivity (50% response rate) is undefined. CONCLUSIONS: Clinical visual field testing may be unreliable when visual field locations have sensitivity below approximately 15 to 19 dB because of a reduction in the asymptotic maximum response probability. Researchers and clinicians may have difficulty detecting worsening sensitivity in these visual field locations, and this difficulty may occur commonly in patients with glaucoma with moderate to severe glaucomatous visual field loss.

Psychometrics of a new questionnaire to assess glaucoma adherence: the Glaucoma Treatment Compliance Assessment Tool (an American Ophthalmological Society thesis).

PURPOSE: To report the psychometrics of the Glaucoma Treatment Compliance Assessment Tool (GTCAT), a new questionnaire designed to assess adherence with glaucoma therapy. METHODS: We developed the questionnaire according to the constructs of the Health Belief Model. We evaluated the questionnaire using data from a cross-sectional study with focus groups (n = 20) and a prospective observational case series (n=58). Principal components analysis provided assessment of construct validity. We repeated the questionnaire after 3 months for test-retest reliability. We evaluated predictive validity using an electronic dosing monitor as an objective measure of adherence. RESULTS: Focus group participants provided 931 statements related to adherence, of which 88.7% (826/931) could be categorized into the constructs of the Health Belief Model. Perceived barriers accounted for 31% (288/931) of statements, cues-to-action 14% (131/931), susceptibility 12% (116/931), benefits 12% (115/931), severity 10% (91/931), and self-efficacy 9% (85/931). The principal components analysis explained 77% of the variance with five components representing Health Belief Model constructs. Reliability analyses showed acceptable Cronbach's alphas (>.70) for four of the seven components (severity, susceptibility, barriers [eye drop administration], and barriers [discomfort]). Predictive validity was high, with several Health Belief Model questions significantly associated (P <.05) with adherence and a correlation coefficient (R (2)) of .40. Test-retest reliability was 90%. CONCLUSION: The GTCAT shows excellent repeatability, content, construct, and predictive validity for glaucoma adherence. A multisite trial is needed to determine whether the results can be generalized and whether the questionnaire accurately measures the effect of interventions to increase adherence.

Determinants of medication adherence to topical glaucoma therapy.

INTRODUCTION/PURPOSE: To determine the associations between medical, demographic, socioeconomic, and ocular factors and adherence to topical glaucoma ocular hypotensive therapy. METHODS: One hundred sixteen patients with ocular hypertension or open-angle glaucoma from 2 tertiary glaucoma services participated in this prospective study. Adherence to ocular hypotensive therapy was measured using an electronic dose monitor (Travatan Dosing Aid, Alcon Laboratories Inc., Fort Worth, TX) and collected data at 3 months after enrollment. We used 3 different definitions of adherence: 1) Definition 1: the proportion of days taking the prescribed number of drops within 3 hours of the prescribed dosing time; 2) Definition 2: the proportion of days taking any drops within 3 hours of the prescribed dosing time; and 3) Definition 3: the proportion of days taking any drops within 6 hours of the prescribed dosing time. Univariate and multivariate models were used to determine the association between the 3 adherence definitions, medical, demographic, socioeconomic, and ocular factors at 3-month follow-up. The main outcome measures for this study were risk factors for poor objective medication adherence. RESULTS: Adherence, using Definition 1, Definition 2, and Definition 3, was 64%, 75%, and 80%, respectively. Age, total number of other eye diseases, and race were significantly associated with full treatment adherence (Definition 1), with race alone significantly predicting 11% of full treatment adherence. For Definition 2, age, income, level of education, and total number of eye diseases were significantly associated with partial adherence (3 h), again race alone significantly predicted 15% of partial adherence (any drops within 3 h). For Definition 3, race, income, level of education, and total number of other eye diseases significantly predicted partial adherence (any drops within 6 h), both race and income predicted 19% of partial treatment adherence. Significant differences for adherence rates between patients of European descent and those of African descent were found for all 3 definitions with those who were less adherent more likely to be of African descent. CONCLUSIONS: Electronic dose monitors provide important information regarding adherence to topical ocular hypotensive medications in glaucoma patients. Electronic dose monitors show low adherence in a significant number of participants. Future studies are needed to determine the reasons for these differences in health behaviors related to glaucoma treatment, which should guide treatment of poor adherence with glaucoma therapy.