Clinical Investigation
Impact of Medication Nonadherence on Hospitalizations and Mortality in Heart Failure

https://doi.org/10.1016/j.cardfail.2011.04.011Get rights and content

Abstract

Background

Limited literature exists on the association between medication adherence and outcomes among patients with heart failure.

Methods and Results

We conducted a retrospective longitudinal cohort study of 557 patients with heart failure with reduced ejection fraction (HFrEF) (defined by EF <50%) in a large health maintenance organization. We used multivariable Cox proportional hazards models to assess the relationship between adherence (with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, β-blockers, and aldosterone antagonists) and the primary outcome of all-cause mortality plus cardiovascular hospitalizations. Mean follow-up time was 1.1 years. Nonadherence (defined as <80% adherence) was associated with a statistically significant increase in the primary outcome in the cohort overall (hazard ratio 2.07, 95% confidence interval 1.62–2.64; P < .0001). This association remained significant when all 3 classes of heart failure medications and the components of the composite end point were considered separately and when the adherence threshold was varied to 70% or 90%.

Conclusions

Medication nonadherence was associated with an increased risk of all-cause mortality and cardiovascular hospitalizations in a community heart failure population. Further research is needed to define systems of care that optimize adherence among patients with heart failure.

Section snippets

Study Population

We conducted a retrospective longitudinal cohort study of members of Kaiser Permanente Colorado (KPCO) with heart failure. KPCO is a nonprofit managed care organization that provides health care services to >450,000 members in the Denver metropolitan area. We identified patients with a primary hospital discharge diagnosis of heart failure (index hospitalization) between January 1, 2001, and December 31, 2006. We included only patients with a primary discharge diagnosis of heart failure, given

Results

The final cohort consisted of 557 patients (Fig. 1). Excluded patients were older, were more likely to be female, and had a higher incidence of depression, chronic obstructive pulmonary disease, stroke, and hypertension. Included patients were more likely to have coronary artery disease and a higher hematocrit at baseline.

Mean follow-up was 1.1 years. Adherent and nonadherent patients are compared in Table 1. As has been shown in hypertension,23 adherent and nonadherent patients could not be

Discussion

In this community-based cohort of patients with HFrEF, medication nonadherence was common and was associated with a significantly higher risk of all-cause mortality or cardiovascular hospitalization. This association was consistent across individual outcomes, definitions of adherence, and classes of heart failure medications. When adherence was defined using only the first 3 months after the index hospitalization, there was no association with the primary outcome.

Adherence to β-blockers was

Conclusions and Implications

We found that nonadherence to evidence-based pharmacotherapies was associated with an increased risk of all-cause mortality or cardiovascular hospitalization in a community-based cohort of patients with HFrEF. There may be significant benefits on mortality and readmission rates from the development of systems of care that improve adherence.

Disclosure

Dr. Ho is a consultant for Wellpoint.

References (33)

  • P.M. Ho et al.

    Effect of medication nonadherence on hospitalization and mortality among patients with diabetes mellitus

    Arch Intern Med

    (2006)
  • P.M. Ho et al.

    Impact of medication therapy discontinuation on mortality after myocardial infarction

    Arch Intern Med

    (2006)
  • J.N. Rasmussen et al.

    Relationship between adherence to evidence-based pharmacotherapy and long-term mortality after acute myocardial infarction

    JAMA

    (2007)
  • J.A. Cramer

    Consequences of intermittent treatment for hypertension: The case for medication compliance and persistence

    Am J Manag Care

    (1998)
  • F.A. Masoudi et al.

    The complexity and cost of drug regimens of older patients hospitalized with heart failure in the United States, 1998-2001

    Arch Intern Med

    (2005)
  • G.H. Gislason et al.

    Persistent use of evidence-based pharmacotherapy in heart failure is associated with improved outcomes

    Circulation

    (2007)
  • Cited by (209)

    • Medication adherence in adults after hospitalization for heart failure: A cross-sectional study

      2024, International Journal of Cardiology: Cardiovascular Risk and Prevention
    View all citing articles on Scopus

    See page 668 for disclosure information.

    View full text