Abstract 1729: Objectively Measured, but Not Self-Reported, Medication Adherence Independently Predicts Event-Free Survival in Patients with Heart Failure

Background: Medication nonadherence is presumed to be related to poor clinical outcomes including emergency department (ED) visits, rehospitalization and mortality, yet this relationship has not been tested using objective adherence measures in patients with heart failure (HF). Therefore, it is unknown which objective indicators of medication adherence predict clinical outcomes and how self-reported adherence measures compare to objective measures in predicting clinical outcomes. Objective: The purpose of this study was to determine which indicators of medication adherence are predictors of event-free survival in patients with HF. Methods: A total of 134 patients with HF (70% male, 61 ±12, 61% NYHA III/IV) were enrolled in this 6-month longitudinal predictive study. Medication adherence was measured using an objective measure, the Medication Event Monitoring System (MEMS) and self-reported adherence from the Medical Outcomes Studies Specific Adherence Scale. Four indicators of adherence were assessed by the MEMS: dose-count, percentage of prescribed doses taken; dose-days, percentage of days the correct number of doses taken; dose-time, percentage of doses taken on schedule; and therapeutic coverage, percentage of time therapeutic drug action maintained. Events (ED visits, rehospitalization, and mortality) were obtained by patient/family interview and hospital databases. Results: In Cox regression, three of the four MEMS indicators, dose-count, dose-day, and therapeutic coverage, predicted time to first event before and after controlling age, gender, ejection fraction, NYHA, angiotensin-converting enzyme inhibitor use, and beta-blocker use ( p = .004, .008, and < .001, respectively). Self-report medication adherence did not predict outcomes ( p = .402). Conclusions: The percentage of prescribed doses taken, percentage of days the correct number of doses taken, and overall therapeutic coverage predicted event-free survival. Neither the percentage of doses taken on schedule nor self-reported adherence predicted outcomes. Healthcare providers should assess specific behaviors related to medication taking rather than a global patient self-assessment of patient adherence.

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Abstract 2728: Nonadherence to Prescribed Medications Mediates the Link between Anxiety and Event-Free Survival in Patients with Heart Failure

Circulation ◽

10.1161/circ.118.suppl_18.s_769-d ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Marla J De Jong ◽

Debra K Moser ◽

Misook L Chung ◽

Jia-Rong Wu

Keyword(s):

Heart Failure ◽

Medication Adherence ◽

Clinical Outcomes ◽

Nyha Class ◽

Event Free Survival ◽

High Anxiety ◽

Medication Nonadherence ◽

Free Survival ◽

Clinical Events ◽

The Relationship

Anxiety has been linked to adverse outcomes for patients with cardiac disease but the mechanism for this relationship is unknown. Nonadherence to prescribed medications is common in heart disease, particularly heart failure (HF), and may mediate the relationship between anxiety and outcomes. To determine if nonadherence to prescribed medications mediates any relationship between anxiety and clinical outcomes in patients with HF. Patients (N=147; age 61±11 yrs, 44% female, 59% NYHA class III/IV) with chronic HF were followed 389±324 days for clinical events (composite of death, emergency department visit, or hospitalization). Patients completed the anxiety subscale of the Brief Symptom Inventory at baseline. Objective evidence of medication adherence was measured with the Medication Event Monitoring System. Survival and regression analyses were used to test whether medication nonadherence mediated any association between anxiety and outcomes. Patients with highest anxiety had shorter event-free survival than patients with lower anxiety (Fig. ). After adjusting for age, gender, and NYHA class in Cox regression, high anxiety predicted (OR 2.4; p=.001) clinical events. Anxiety predicted medication doses taken (p=.01) and days correct doses taken (p=.008). Medication doses taken (p=.01) and days dose taken (p=.008) also predicted clinical outcomes. Medication nonadherence mediated the relationship between high anxiety and worse outcomes. This is the first study to show that medication nonadherence links anxiety and clinical outcomes. Interventions that decrease anxiety may improve both medication adherence and outcomes.

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Medication Adherence, Depressive Symptoms, and Cardiac Event–Free Survival in Patients With Heart Failure

Journal of Cardiac Failure ◽

10.1016/j.cardfail.2013.03.010 ◽

2013 ◽

Vol 19 (5) ◽

pp. 317-324 ◽

Cited By ~ 35

Author(s):

Jia-Rong Wu ◽

Terry A. Lennie ◽

Rebecca L. Dekker ◽

Martha J. Biddle ◽

Debra K. Moser

Keyword(s):

Heart Failure ◽

Depressive Symptoms ◽

Medication Adherence ◽

Cardiac Event ◽

Event Free Survival ◽

Free Survival ◽

Patients With Heart Failure

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Medication Adherence Mediates the Relationship between Ethnicity and Event-Free Survival in Patients with Heart Failure

Journal of Cardiac Failure ◽

10.1016/j.cardfail.2008.06.267 ◽

2008 ◽

Vol 14 (6) ◽

pp. S95-S96

Author(s):

Jia-Rong Wu ◽

Debra K. Moser ◽

Terry A. Lennie ◽

Misook L. Chung ◽

Marla J. De Jong

Keyword(s):

Heart Failure ◽

Medication Adherence ◽

Event Free Survival ◽

Free Survival ◽

Patients With Heart Failure ◽

The Relationship

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Abstract 5961: Defining An Evidence-Based Cutpoint for Medication Adherence in Heart Failure

Circulation ◽

10.1161/circ.118.suppl_18.s_1039-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Jia-Rong Wu ◽

Terry A Lennie ◽

Marla J De Jong ◽

Mary Kay Rayens ◽

Misook L Chung ◽

...

Keyword(s):

Heart Failure ◽

Medication Adherence ◽

Cox Regression ◽

Enzyme Inhibitor ◽

Roc Curves ◽

Evidence Based ◽

List Type ◽

Medication Regimen ◽

Event Free Survival ◽

Free Survival

Patients with heart failure (HF) are required to take multiple medications. Long-term adherence to the HF medication regimen is necessary in order to achieve better patient outcomes. Despite the importance of adherence, clinically relevant cutpoints for distinguishing the level of adherence associated with outcomes are unknown. The purpose of this study was to use outcomes (i.e., event-free) as a criterion to determine the level of medication adherence required to achieve the best clinical outcomes. The specific aim was to determine the cutpoint above which there is a positive relationship between level of medication adherence and outcomes. This was a longitudinal study of 135 patients with HF. Medication adherence was measured using a valid and objective measure, the Medication Event Monitoring System (MEMS). Two indicators of adherence were assessed by the MEMS: dose-count, percentage of prescribed doses taken and dose-days, percentage of days correct number of doses taken. Patients were followed up to 3.5 years to collect data on outcomes. A series of Kaplan-Meier plots with log-rank tests, Cox-survival analyses, and receiver operating characteristic (ROC) curves were assessed comparing event-free survival in patients divided at one point incremental cutpoints. Event-free survival was significantly better when the prescribed number of doses taken [dose-count] or the correct dose [dose-day]) was ≥ 88%. This level was confirmed in a Cox regression model controlling for age, gender, ejection fraction, NYHA, comorbidity, angiotensin-converting enzyme inhibitor use, and beta-blocker use. ROC curves showed that adherence rates above 88 – 89% produced the optimal combination of sensitivity and specificity with respect to predicting better event-free survival. With this as the adherence cutpoint, patients in the nonadherent group were 2.2 times (by dose-count) to 3.2 times (by dose-day) more likely to experience a first event ( p = .021 and .002, respectively), compared to patients in the adherent group. The results of this study provide clinicians and researchers with an evidence-based recommendation about the level of adherence needed to achieve the best outcomes.

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