Health-Related Quality of Life Is a Mediator of the Relationship Between Medication Adherence and Cardiac Event-Free Survival in Patients with Heart Failure

https://doi.org/10.1016/j.cardfail.2021.03.004Get rights and content

Abstract

Background

Health-related quality of life (HRQOL) is an important patient-reported outcome that is related to medication adherence, hospitalization and death. The nature of the relationships among medication adherence, HRQOL, and hospitalization and death is unknown. We sought to determine the relationships among medication adherence, HRQOL, and cardiac event-free survival in patients with heart failure.

Methods and Results

We enrolled 218 patients with heart failure. Patients’ medication adherence was measured objectively using the Medication Event Monitoring System. HRQOL was assessed using the Minnesota Living with Heart Failure Questionnaire. Patients were followed for up to 3.5 years to collect hospitalization and mortality data. Mediation analysis was used to determine the nature of the relationships among the variables. Patients with better medication adherence had better HRQOL (P = .014). Medication adherence and HRQOL were associated with cardiac event-free survival (both P < .05). Patients with medication nonadherence were 1.86 times more likely to experience a cardiac event than those with better medication adherence (P = .038). Medication adherence was not associated with cardiac event-free survival after entering HRQOL in the model (P = .118), indicating mediation by HRQOL of the relationship between medication adherence and cardiac event-free survival.

Conclusions

HRQOL mediated the relationship between medication adherence and cardiac event-free survival. It is important to assess medication adherence and HRQOL regularly and develop interventions to improve medication adherence and HRQOL to decrease hospitalization and mortality in patients with heart failure.

Section snippets

Study Design

This was a prospective, observational study. To increase sample size, we used data from 2 prospective, longitudinal studies in this secondary data analysis.18,25 Both studies explored the relationships among psychosocial and behavioral factors and outcomes (eg, HRQOL and event-free survival).26,33 The inclusion and exclusion criteria and the measures of medication adherence, HRQOL, and cardiac events were the same in both studies.26,33 In this study, we explored the relationship among

Patient Characteristics

A total of 218 patients with HF and complete MEMS data were included in the analysis (Table 1). There were no differences in sample characteristics between the 232 patients in the original studies and the 218 patients in this study. The mean age and standard deviation of the patients was 60 ± 12 years. The majority of patients were taking a beta-blocker (91%) and angiotensin-converting enzyme inhibitor (71%). There were 82 patients in study 1 and 136 patients in study 2. The percentage of

Discussion

In this study, we explored the relationships among medication adherence, HRQOL, and cardiac event-free survival in patients with HF. We found that medication adherence and HRQOL both independently were associated with cardiac event-free survival in patients with HF. We previously reported that medication nonadherence was associated with higher risk of cardiac events.26,36 Patients with nonadherence to prescribed medications had 2.2 times the risk of experiencing a cardiac event than those with

Limitations

First, although medication adherence measured by the MEMS is a gold standard, there is no guarantee that patients take their medication each time they open the medication cap. However, the MEMS is the most commonly used objective measure of adherence and is considered to be the reference measure of medication adherence in the research settings.55

Second, medication adherence was measured in different duration of 2 studies. The difference in duration may have a potential influence on the recorded

Conclusions

Better medication adherence is associated with better HRQOL. HRQOL mediated the relationship between medication adherence and cardiac event-free survival. Both medication adherence and HRQOL independently and in combination were associated with cardiac event-free survival in this sample. Medication adherence and patient HRQOL are important on patient health outcomes. Regular assessment and interventions to improve medication adherence and HRQOL are needed for better clinical outcomes.

Disclosures

The authors have nothing to disclose.

References (55)

  • PA Heidenreich et al.

    Health status identifies heart failure outpatients at risk for hospitalization or death

    J Am Coll Cardiol

    (2006)
  • ML Chung et al.

    Patients differ in their ability to self-monitor adherence to a low-sodium diet versus medication

    J Card Fail

    (2008)
  • JR Wu et al.

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

    Am Heart J

    (2009)
  • DK Moser et al.

    Improvement in health-related quality of life after hospitalization predicts event-free survival in patients with advanced heart failure

    J Card Fail

    (2009)
  • H Faller et al.

    Is health-related quality of life an independent predictor of survival in patients with chronic heart failure?

    J Psychosom Res

    (2007)
  • SS Virani et al.

    Heart disease and stroke statistics-2020 update: a report from the American Heart Association

    Circulation

    (2020)
  • JR Wu et al.

    Health-related quality of life, functional status, and cardiac event-free survival in patients with heart failure

    J Cardiovasc Nurs

    (2016)
  • JR Wu et al.

    Dietary vitamin C deficiency is associated with health-related quality of life and cardiac event-free survival in adults with heart failure

    J Cardiovasc Nurs

    (2019)
  • MH Chin et al.

    Factors contributing to the hospitalization of patients with congestive heart failure

    Am J Public Health

    (1997)
  • MA Chui et al.

    Association between adherence to diuretic therapy and health care utilization in patients with heart failure

    Pharmacotherapy

    (2003)
  • MB Happ et al.

    Factors contributing to rehospitalization of elderly patients with heart failure

    J Cardiovasc Nurs

    (1997)
  • PP Joshi et al.

    Factors precipitating congestive heart failure–role of patient non-compliance

    J Assoc Physicians India

    (1999)
  • H Li et al.

    Post-acute home care and hospital readmission of elderly patients with congestive heart failure

    Health Soc Work

    (2004)
  • T Miura et al.

    Effect of digoxin noncompliance on hospitalization and mortality in patients with heart failure in long-term therapy: a prospective cohort study

    Eur J Clin Pharmacol

    (2001)
  • WY Lam et al.

    Medication adherence measures: an overview

    Biomed Res Int

    (2015)
  • MJ Stirratt et al.

    Self-report measures of medication adherence behavior: recommendations on optimal use

    Transl Behav Med

    (2015)
  • LG Park et al.

    Electronic measurement of medication adherence

    West J Nurs Res

    (2015)
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    Supported by funding from the Philips Medical-American Association of Critical Care Nurses Outcomes Grant, American Heart Association Great River Affiliate Post-doctoral Fellowship to Jia-Rong Wu and by funding from the National Institute of Nursing Research (NINR): K23NR014489 (J. Wu, PI), University of Kentucky Clinical and Translational Science Center (M01RR02602). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

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