Impact of interventions on medication adherence and blood pressure control in patients with essential hypertension: a systematic review by the ISPOR medication adherence and persistence special interest group.

OBJECTIVES: To systematically review the evidence on the impact of interventions to improve medication adherence in adults prescribed antihypertensive medications. METHODS: An electronic search was undertaken of articles published between 1979 and 2009, without language restriction, that focused on interventions to improve antihypertensive medication adherence among patients (≥18 years) with essential hypertension. Studies must have measured adherence as an outcome of the intervention. We followed standard guidelines for the conduct and reporting of the review and conducted a narrative synthesis of reported data. RESULTS: Ninety-seven articles were identified for inclusion; 35 (35 of 97, 36.1%) examined interventions to directly improve medication adherence, and the majority (58 of 97, 59.8%) were randomized controlled trials. Thirty-four (34 of 97, 35.1%) studies reported a statistically significant improvement in medication adherence. DISCUSSION/CONCLUSIONS: Interventions aimed at improving patients' knowledge of medications possess the greatest potential clinical value in improving adherence with antihypertensive therapy. However, we identified several limitations of these studies, and advise future researchers to focus on using validated adherence measures, well-designed randomized controlled trials with relevant adherence and clinical outcomes, and guidelines on the appropriate design and analysis of adherence research.

A framework for planning and critiquing medication compliance and persistence research using prospective study designs.

BACKGROUND: Medication compliance and persistence are important determinants of clinical outcomes. With the application of evidence-based therapy, it is increasingly important to ensure that studies that use compliance or persistence as a primary or secondary outcome are designed suitably and employ appropriate analyses to support the inferences made. OBJECTIVE: The aim of this work was to describe the designs of medication compliance/persistence studies and provide guidance on appropriate analyses, with the ultimate goal of helping health providers and payers of health care understand the impact of compliance and persistence on health outcomes. METHODS: MEDLINE, CINAHL, EMBASE, and all EBM Reviews databases were searched to locate key research articles about prospective medication compliance and persistence studies. Articles published between 1978 and 2008 were included in the search. Inclusion criteria included a focus on medication compliance and persistence, and prospective research designs. Articles that largely focused on retrospective study designs or were based on opinion rather than evidence were excluded. RESULTS: A systematic framework was developed that comprised a prospective checklist and a quantitative tool to assess the quality of studies. The key elements of the checklist included the following: title and abstract, introduction or background, objectives, methods and study design, statistical analysis and results, discussion, conclusions, and disclosure of conflicts of interest. For each element, examples are provided to help readers make an informed decision about the design, value, and quality of a particular prospective study. CONCLUSIONS: The checklist and quantitative tool can be used to provide objective validation of the rigor of prospective research designs. It is anticipated that future research will follow a uniform approach to presentation and evaluation of data, thereby facilitating a clear understanding of the impact of compliance and persistence on health outcomes.

Pilot study to determine the impact of a multidisciplinary educational intervention in patients hospitalized with heart failure.

BACKGROUND: Patients with heart failure (HF) face challenges complying with multidrug regimens. OBJECTIVES: To examine the impact of a compliance enhancing intervention on medication compliance and morbidity in HF. DESIGN: Patients were randomized to either usual care or an inhospital educational intervention delivered by a multidisciplinary team (Intervention). SETTING: Acute medical and surgical units at a teaching hospital. PATIENTS: One hundred thirty four patients with a clinical diagnosis of HF and a left ventricular ejection fraction of < 40% requiring long-term medical treatment. MAIN OUTCOME MEASURES: A validated HF-specific instrument provided a measure of knowledge. We characterized patients as noncompliant if pharmacy refill data suggested they had taken < or = 0.80 of their medication. We measured quality of life using the Minnesota Living with Heart Failure Questionnaire and the Short Form 36 and conducted a time to first event analysis of a composite end point including mortality, readmissions, and emergency department visits. RESULTS: The Intervention group showed higher knowledge scores at discharge and 1 year (P = .05). The risk of noncompliance in Intervention patients varied from 0.78 (95% CI 0.33-1.89) for ACE-I (13% Intervention, 17% Control) to 1.02 (0.49-2.12) for diuretics (23% Intervention, 23% Control). Quality of life improved in both groups over time; the only difference between groups favored the Intervention (Minnesota Living with Heart Failure Questionnaire, P = .04). The composite end point occurred in 67% of control and 60% of Intervention patients (hazard ratio 0.85, 95% CI 0.55-1.30). CONCLUSIONS: An inhospital educational intervention improved knowledge and, possibly, quality of life and may be useful as part of a comprehensive compliance enhancing strategy in patients with HF.

A systematic review and meta-analysis of studies comparing readmission rates and mortality rates in patients with heart failure.

BACKGROUND: Heart failure is the leading cause of hospitalization and readmission in many hospitals worldwide. We performed a meta-analysis to evaluate the effectiveness of multidisciplinary heart failure management programs on hospital admission rates. METHODS: We identified studies through an electronic search and mortality using 8 distinct methods. Eligible studies met the following criteria: (1) randomized controlled clinical trials of adult inpatients hospitalized for heart failure enrolled either at the time of discharge or within 1 week after discharge; (2) heart failure-specific patient education intervention coupled with a postdischarge follow-up assessment; and (3) unplanned readmission reported. Four reviewers independently assessed each study for eligibility and quality, achieving a weighted kappa of 0.73 for eligibility and 0.77 for quality. For each study we calculated the relative risk for readmissions and mortality for patients receiving enhanced education relative to patients receiving usual care. RESULTS: A total of 529 citation titles were identified, of which 8 randomized trials proved eligible. The pooled relative risk for hospital readmission rates using a random-effects model was 0.79 (95% confidence interval, 0.68-0.91; P<.001; heterogeneity P = .25). There was no apparent effect on mortality (relative risk, 0.98; 95% confidence interval, 0.72-1.34; P = .90; heterogeneity P = .20). Data were insufficient to meaningfully pool intervention effects on quality of life or compliance. CONCLUSION: This systematic review suggests that specific heart failure-targeted interventions significantly decrease hospital readmissions but do not affect mortality rates.