Review: Medication adherence may reduce mortality and morbidity
ACP J Club. 1998 Mar-April; 128:53. doi:10.7326/ACPJC-1998-128-2-053
McDermott MM, Schmitt B, Wallner E. Impact of medication nonadherence on coronary heart disease outcomes: a critical review. Arch Intern Med. 1997 Sep 22;157:1921-9.
To determine whether adherence to medication reduces mortality, morbidity, hospitalization, and restenosis in patients with or at risk for coronary artery disease or congestive heart failure.
Studies were identified with MEDLINE searches (1966 to May 1996) using the terms coronary disease; heart failure, congestive; patient compliance; patient readmission; patient dropouts; cooperative behavior; treatment refusal; patient education; treatment outcome; diabetes; hypertension; compliance; noncompliance; and hypercholesterolemia. Bibliographies of relevant papers were checked, and experts were contacted.
Studies were selected if they reported original research relating medication adherence with the specific outcomes of new cardiovascular events; if they documented progression of atherosclerosis, hospitalizations, or survival; and if patients had or were at risk for coronary artery disease (diabetes, hypertension, or hypercholesterolemia) or congestive heart failure.
A second reviewer extracted and checked data on study design and quality; patient characteristics; and outcomes and their assessment, including blinding, adherence, and results.
289 articles were identified, 179 were chosen for full assessment, and 20 met inclusion criteria. 4 of 6 studies that assessed mortality as a separate outcome showed that medication adherence was associated with a reduction in mortality rates. 3 of 6 studies that assessed hospitalization rates showed that medication adherence was associated with decreased hospitalization; 1 study had insufficient power to show an association. 3 of 6 studies of coronary heart disease events or signs and symptoms of congestive heart failure showed an association between improved outcomes and compliance. Restenosis was assessed in 2 studies, and neither showed an association between adherence and outcomes. 2 of 3 studies showed that adherence with placebo was associated with lower mortality rates.
Adherence with medication may reduce mortality and morbidity in patients with or at risk for coronary artery disease or congestive heart failure.
Source of funding: No external funding.
For article reprint: Dr. M.M. McDermott, 303 East Ohio Street, Suite 300, Chicago, IL 60611, USA. FAX 312-908-0951. E-mail MDM608@lulu.acns.nwu.edu.
The systematic review by McDermott and colleagues provides good news: better outcomes for patients at cardiovascular risk when they adhere to prescribed regimens for reducing risk factors and improving cardiovascular function.
A simple relation is not always found between taking a pill this week and blocking pathophysiologic events in the future. For at least some cardiotropic medications, such as β-blockers, withdrawal phenomena or rebound effects may occur with intermittent compliance. Moreover, the finding of improved outcomes associated with compliance with placebo suggests that the benefits are at least partly mediated by patients attempting to cope and not just by pharmacologic effects.
Clinicians, who often despair of effective interventions to change patient behavior, may feel frustrated. Although offering the promise of improved outcomes, the review gives little guidance about how to improve adherence. Indeed, the past compliance literature has focused more on documenting the problem of nonadherence than on showing feasible and effective remediation. Several promising strategies to enhance compliance that are now emerging include the use of telephone contacts between scheduled visits (1), computer-based and telephone-mediated monitoring of patients (2), and nurse-mediated and protocol-supported programs (3).
Other exciting work has used electronic monitoring of medication-taking behavior to evaluate, treat, and overcome triggers and patterns of nonadherence (4). These developments will permit exploration beyond pill counts, clinician opinion, and patient self-report. The good news is getting better.
Peter Rudd, MD
Stanford University Medical CenterStanford, California, USA
2. Friedman RH, Kazis LE, Jette A, et al. A telecommunications system for monitoring and counseling patients with hypertension. Impact on medication adherence and blood pressure control. Am J Hypertens. 1996;9:285-92.
4. Cramer JA. Identifying and improving compliance patterns: a composite plan for health care providers. In: Cramer JA, Spilker B, eds. Patient Compliance in Medical Practice and Clinical Trials. New York: Raven Press; 1991: 387-92.