Misook L. Chung

Predictors of medication adherence using a multidimensional adherence model in patients with heart failure.

BACKGROUND Medication adherence in heart failure (HF) is a crucial but poorly understood phenomenon. The purpose of this study was to explore factors contributing to medication adherence in patients with HF by using the World Health Organizations multidimensional adherence model. METHODS AND RESULTS Patients (N = 134) with HF (70% were male, aged 61 +/- 12 years, 61% with New York Heart Association III/IV) were studied to determine the predictors of medication adherence derived from the multidimensional adherence model. Medication adherence was measured objectively using the medication event monitoring system for 3 months. Three indicators of adherence were assessed by the medication event monitoring system: 1) dose-count, the percentage of prescribed doses taken; 2) dose-days, the percentage of days the correct number of doses were taken; and 3) dose-time, the percentage of doses that were taken on schedule. Barriers to medication adherence, ethnicity, and perceived social support predicted dose-count (P < .001). New York Heart Association functional class, barriers to medication adherence, financial status, and perceived social support predicted dose-day (P < .001). Barriers to medication adherence and financial status predicted dose-time (P = .005). CONCLUSION A number of modifiable factors predicted medication adherence in patients with HF, providing specific targets for intervention.

Objectively Measured, but Not Self-Reported, Medication Adherence Independently Predicts Event-Free Survival in Patients With Heart Failure

OBJECTIVE Medication nonadherence is presumed to be related to poor clinical outcomes, yet this relationship rarely has been tested using objective adherence measures in patients with heart failure. Which objective indicators of medication adherence predict clinical outcomes are unknown. The study objective was to determine which indicators of medication adherence are predictors of event-free survival. METHODS Patients (N = 134) with heart failure (69% were male, aged 61 +/- 11 years, 61% with New York Heart Association class III/IV heart disease) were enrolled in this 6-month longitudinal study. Adherence was measured using two measures: 1) an objective measure, the Medication Event Monitoring System (MEMS); and 2) self-reported adherence (Medical Outcomes Studies Specific Adherence Scale). Three indicators of adherence were assessed by MEMS: 1) dose-count, percentage of prescribed doses taken; 2) dose-days, percentage of days correct number of doses taken; and 3) dose-time, percentage of doses taken on schedule. Events (emergency department visits, rehospitalization, and mortality) were obtained by patient/family interview and hospital databases. RESULTS In Cox regression, two of the three MEMS indicators, dose-count and dose-day, predicted event-free survival before and after controlling for age, gender, ejection fraction, New York Heart Association class, angiotensin-converting enzyme inhibitor use, and beta-blocker use (P = .004, P = .008, and P = .224, respectively). Self-report adherence did not predict outcomes (P = .402). CONCLUSION Dose-count and dose-day predicted event-free survival. Neither dose-time nor self-reported adherence predicted outcomes. Health care providers should assess specific behaviors related to medication taking rather than a global patient self-assessment of patient adherence.

Defining an evidence-based cutpoint for medication adherence in heart failure

BACKGROUND Despite the importance of medication adherence in heart failure, clinically relevant cutpoints for distinguishing the level of adherence associated with outcomes are unknown. OBJECTIVE The purpose of this study is to determine the cutpoint above which there is a positive relationship between level of medication adherence and event-free survival. METHODS This was a longitudinal study of 135 patients with heart failure. Medication adherence was measured using a valid and objective measure, the Medication Event Monitoring System. Two indicators of adherence were assessed by the Medication Event Monitoring System (AARDEX, Union City, CA): (1) dose count, percentage of prescribed doses taken, and (2) dose days, percentage of days the correct number of doses was 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 curves were assessed comparing event-free survival in patients divided at one-point incremental cutpoints. RESULTS Event-free survival was significantly better when the prescribed number of doses taken (dose count) or the correct dose (dose day) was > or =88%. This level was confirmed in a Cox regression model controlling for age, gender, ejection fraction, New York Heart Association, comorbidity, angiotensin-converting enzyme inhibitor use, and beta-blocker use. Receiver operating characteristic curves showed that adherence rates above 88% produced the optimal combination of sensitivity and specificity with respect to predicting better event-free survival. With 88% as the adherence cutpoint, the hazard ratio for time to first event for the nonadherent group was 2.2 by dose count (P = .021) and 3.2 by dose day (P = .002). CONCLUSION The results of this study provide clinicians and researchers with an evidence-based recommendation about the level of adherence needed to achieve optimal clinical outcomes.

Comparison of prevalence of symptoms of depression, anxiety, and hostility in elderly patients with heart failure, myocardial infarction, and a coronary artery bypass graft.

OBJECTIVE This study sought to compare the prevalence of anxiety, depression, and hostility among 3 clinically diverse elderly cardiac patient cohorts and a reference group of healthy elders. METHODS This was a multicenter, comparative study. A total of 1167 individuals participated: 260 healthy elders, and 907 elderly cardiac patients who were at least 3 months past a hospitalization (478 heart-failure patients, 298 postmyocardial infarction patients, and 131 postcoronary artery bypass graft patients). Symptoms of anxiety, depression, and hostility were measured using the Multiple Affect Adjective Checklist. RESULTS The prevalence of anxiety, depression, and hostility was higher in patients in each of the cardiac patient groups than in the group of healthy elders. Almost three quarters of patients with heart failure reported experiencing symptoms of depression, and the heart-failure group manifested the greatest percentage of patients with depressive symptoms. CONCLUSIONS The high levels of emotional distress common in cardiac patients are not a function of aging, because healthy elders exhibit low levels of anxiety, depression, and hostility.

Gender differences in and factors related to self-care behaviors: A cross-sectional, correlational study of patients with heart failure

BACKGROUND Although self-care may reduce exacerbations of heart failure, reported rates of effective self-care in patients with heart failure are low. Modifiable factors, including psychosocial status, knowledge, and physical factors, are thought to influence heart failure self-care, but little is known about their combined impact on self-care. OBJECTIVES The objective of this study was to identify factors related to self-care behaviors in patients with heart failure. DESIGN A cross-sectional, correlational study design was used. PARTICIPANTS AND SETTINGS One hundred twenty-two patients (77 men and 45 women, mean age 60+/-12 years old, 66% New York Heart Association functional class III/IV) were recruited from the outpatient clinics of an academic medical center and two community hospitals. METHODS Data on self-care behaviors (Self-Care of Heart Failure Index), depressive symptoms, perceived control, self-care confidence, knowledge, functional status, and social support were collected. Factors related to self-care were examined using hierarchical multiple regression. RESULTS Mean self-care behavior scores were less than 70 indicating the majority of men and women with HF did not consistently engage in self-care behaviors. Higher self-care confidence and perceived control and better heart failure management knowledge were associated with better self-care (r2=.25, p<.001). Higher perceived control and better knowledge were related to better self-care behaviors in men (r2=.18, p=.001), while higher self-care confidence and poorer functional status were related to better self-care behaviors in women (r2=.35, p<.001). CONCLUSION This study demonstrates the substantial impact of modifiable factors such as confidence in ones self-care abilities, perceived control, and knowledge on self-care behaviors. This study demonstrates that there are gender differences in factors affecting self-care, even though at baseline men and women have similar knowledge levels, physical, psychological, and behavioral status. Effective interventions focusing on modifiable factors and the unique characteristics of men and women should be provided to improve self-care behaviors in patients with heart failure.

A text messaging intervention to promote medication adherence for patients with coronary heart disease: A randomized controlled trial

OBJECTIVE Pharmacologic treatment for secondary prevention of coronary heart disease (CHD) is critical to prevent adverse clinical outcomes. In a randomized controlled trial, we compared antiplatelet and statin adherence among patients with CHD who received: (1) text messages (TM) for medication reminders and education, (2) educational TM only, or (3) No TM. METHODS A mobile health intervention delivered customized TM for 30 days. We assessed and analyzed medication adherence with electronic monitoring devices [Medication Event Monitoring System (MEMS)] by one-way ANOVA and Welch tests, two-way TM response rates by t-tests, and self-reported adherence (Morisky Medication Adherence Scale) by Repeated Measures ANOVA. RESULTS Among 90 patients (76% male, mean age 59.2 years), MEMS revealed patients who received TM for antiplatelets had a higher percentage of correct doses taken (p=0.02), percentage number of doses taken (p=0.01), and percentage of prescribed doses taken on schedule (p=0.01). TM response rates were higher for antiplatelets than statins (p=0.005). Self-reported adherence revealed no significant differences among groups. CONCLUSION TM increased adherence to antiplatelet therapy demonstrated by MEMS and TM responses. PRACTICE IMPLICATIONS Feasibility and high satisfaction were established. Mobile health interventions show promise in promoting medication adherence.

Three Gram Sodium Intake is Associated With Longer Event-Free Survival Only in Patients With Advanced Heart Failure

BACKGROUND There is limited evidence to support the recommendation that patients with heart failure (HF) restrict sodium intake. The purpose of this study was to compare differences in cardiac event-free survival between patients with sodium intake above and below 3 g. METHODS A total of 302 patients with HF (67% male, 62 ± 12 years, 54% New York Heart Association [NYHA] Class III/IV, ejection fraction 34 ± 14%) collected a 24-hour urine sodium (UNa) to indicate sodium intake. Patients were divided into 2 groups using a 3-g UNa cutpoint and stratified by NYHA Class (I/II vs. III/IV). Event-free survival for 12 months was determined by patient or family interviews and medical record review. Differences in cardiac event-free survival were determined by Kaplan-Meier survival curve with log-rank test and Cox hazard regression. RESULTS The Cox regression hazard ratio for 24-hour UNa ≥ 3 g in NYHA Class I/II was 0.44 (95% confidence interval [CI] = 0.20-0.97) and 2.54 (95% CI = 1.10-5.84) for NYHA III/IV after controlling for age, gender, HF etiology, body mass index, ejection fraction, and total comorbidity score. CONCLUSIONS These data suggest that 3 g dietary sodium restriction may be most appropriate for patients in NYHA functional Classes III and IV.

Heart Failure Self-care in Developed and Developing Countries

BACKGROUND Heart failure (HF) self-care is poor in developed countries like the United States, but little is known about self-care in developing countries. METHODS AND RESULTS A total of 2082 adults from 2 developed (United States and Australia) and 2 developing countries (Thailand and Mexico) were studied in a descriptive, comparative study. Self-care was measured using the Self-Care of HF Index, which provided scores on self-care maintenance, management, and confidence. Data were analyzed using regression analysis after demographic (age, gender, education), clinical (functional status, experience with the diagnosis, comorbid conditions), and setting of enrollment (hospital or clinic) differences were controlled. When adequate self-care was defined as a standardized score >or=70%, self-care was inadequate in most scales in most groups. Self-care maintenance was highest in the Australian sample and lowest in the Thai sample (P < .001). Self-care management was highest in the US sample and lowest in the Thai sample (P < .001). Self-care confidence was highest in the Mexican sample and lowest in the Thai sample (P < .001). Determinants differed for the three types of self-care (eg, experience with HF was associated only with self-care maintenance). CONCLUSION Interventions aimed at improving self-care are greatly needed in both the developed and the developing countries studied.

Anxiety is Not Manifested by Elevated Heart Rate and Blood Pressure in Acutely Ill Cardiac Patients

Background: Accurate assessment of anxiety in cardiac patients is important because anxiety is associated with adverse outcomes. Clinicians often use heart rate and blood pressure as indicators of anxiety; however, little is known about whether these measures accurately reflect anxiety in acutely ill patients. Aims: The purpose of this study was to determine whether heart rate and blood pressure were related to level of anxiety in patients with chronic advanced heart failure (HF), patients with acute myocardial infarction (AMI), and healthy individuals. Methods and Results: In this descriptive, correlational study, anxiety, heart rate, and blood pressure were measured at the same time in three groups of individuals: (1) 54 patients hospitalized for AMI; (2) 32 patients with chronic advanced HF; and (3) 31 healthy individuals. State anxiety was measured using the anxiety subscale of the Brief Symptom Inventory. Heart rate and blood pressure data were collected immediately prior to the anxiety assessment. Data were collected in the outpatient setting for patients with HF and healthy individuals. For patients with AMI, data were collected a mean of 48±33 h after admission. There were no correlations between anxiety and heart rate or diastolic blood pressure. Higher anxiety was associated with lower systolic blood pressure in patients with AMI (r=−0.23, P<0.05) and in healthy individuals (r=−0.27, P<0.05). Conclusion: Elevated heart rate and blood pressure do not accurately reflect level of anxiety as reported by patients with HF or AMI and healthy individuals, and thus cannot be used to assess anxiety in acutely ill patients. Clinicians who use changes in heart rate or blood pressure as indicators of anxiety may fail to recognize and treat anxiety, placing their patients at high risk for both immediate and long-term complications.

Marital Status as an Independent Predictor of Event-Free Survival of Patients With Heart Failure

BACKGROUND Depressive symptoms are a well-known predictor of mortality in patients with heart failure, and positive spousal support is associated with improved outcomes in these patients. However, in the context of depressive symptoms, the effect on survival of having a spouse is unknown. OBJECTIVE To determine the effect of marital status on event-free survival in patients with heart failure who did or did not have depressive symptoms. METHODS Depressive symptoms were assessed by using the Beck Depression Inventory-II in patients with heart failure who were followed-up for up to 4 years to collect data on mortality and hospitalizations. Patients were grouped according to the presence and absence of depressive symptoms by using the standard cutoff score of 14 on the Beck Depression Inventory-II. Kaplan-Meier and Cox regression analyses were used to compare event-free survival for married and nonmarried patients who were stratified according to the presence or absence of depressive symptoms. RESULTS Of 166 patients, 56% were married, and 33% had depressive symptoms. Levels of depressive symptoms were similar between married and nonmarried patients (10.9 vs 12.1; P = .39). Married patients experienced longer event-free survival than did nonmarried patients (P = .009), even with stratification according to depressive symptoms (P = .01). CONCLUSIONS Patients with a spouse had longer event-free survival than nonmarried patients did, even in the context of depressive symptoms.