Assessment of adherence to medication in patients after myocardial infarction treated with percutaneous coronary intervention. Is there a place for newself-reported questionnaires?

INTRODUCTION

Non-adherence to medication regimen after myocardial infarction (MI) leads to increased morbidity and mortality and generates additional cost to the healthcare system.

OBJECTIVES

The aim of this systematic review was to critically discuss assessment methods of adherence to medication in patients after myocardial infarction treated with percutaneous coronary intervention and the possible application of a new self-reported questionnaire.

METHODS

A systematic investigation of all published literature was conducted to minimize the risk of bias. A database search (PubMed, CENTRAL and Google Scholar databases) from January 1998 through December 2017.

RESULTS

Adequate assessment of patient adherence to treatment is necessary to understand the potential for adverse outcomes. Methods developed for adherence evaluation are classified as subjective and objective or as direct and indirect. Direct, objective measures reflect pharmacokinetics and include measurement of the drug or its metabolite concentration, evaluation of the presence of biological markers given with the drug and direct observation of patients' medication-taking behavior. Several indirect, objective methods are based on evaluation of the availability of prescribed medications assuming that medication is taken exactly as prescribed. Assessment of the effectiveness of treatment, both at the pharmacodynamic and clinical level, indirectly but objectively reflects adherence to treatment. Subjective methods, including patient-kept diaries, patient interviews and self-reported questionnaires, due to their simplicity, real-time feedback and low cost, are often used for adherence evaluation in clinical practice.

CONCLUSIONS

In spite of the availability, convenience and variety of methods, measuring adherence still remains a real challenge. Using a well designed questionnaire provides an opportunity to identify patients at increased risk of non-adherence and the obstacles impeding implementation of the treatment plan, allowing implementation of tailored interventions in order to improve patient medication-taking behavior.