Self-reported adverse drug events and the role of illness perception and medication beliefs in ambulatory heart failure patients: A cross-sectional survey.

BACKGROUND

Identifying patients with heart failure (HF) who are at risk of experiencing symptomatic adverse drug events (ADEs) is important for improving patient care and quality of life. Several demographic and clinical variables have been identified as potential risk factors for ADEs but limited knowledge is available on the impact of HF patients' beliefs and perceptions on their experience of ADEs.

OBJECTIVE

The purpose of the study was to identify the relationship between HF patients' illness perception and medication beliefs and self-reported ADEs.

DESIGN

A cross-sectional survey was performed between November 2008 and March 2009.

SETTINGS

One university medical centre, two regional hospitals and 20 general practitioners in the Netherlands participated in the study.

PARTICIPANTS

495 patients with HF were included.

METHODS

Patients completed the validated Revised Illness Perception Questionnaire (IPQ-R) and the Beliefs about Medication Questionnaire (BMQ) which collected data on their illness perception and medication beliefs. In addition, data on ADEs as experienced in the previous four weeks were collected through an open-ended question and a symptom checklist. Multivariate logistic regression was performed to identify factors associated with these ADEs.

RESULTS

In total, 332 (67%) patients had experienced ADEs in the previous four weeks, of whom 28% reported dry mouth, 27% dizziness and 19% itchiness as the most prevalent. In the adjusted multivariate analysis, disease-related symptoms (illness identity) (OR for 1-5 symptoms 3.57; 95% CI 2.22-5.75, OR for >5 symptoms 7.37; 95% CI 3.44-15.8), and general beliefs about medication overuse (OR 1.07; 95% CI 1.01-1.13) were independently associated with experiencing ADEs, whereas none of the demographic or clinical factors were significant.

CONCLUSIONS

HF patients who perceive a high number of disease symptoms and have negative medication beliefs are at higher risk of experiencing self-reported ADEs. We suggest that future studies and interventions to improve ADE management should focus on negative medication beliefs and assisting patients in differentiating disease symptoms from ADEs.