Investigating the impact of illness perceptions on long-term adherence to statin medication in myocardial infarction patients
Authors: Crowson NA , Keenan J , Roberts LH 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): National Institute for Health Research (NIHR) Biomedical Research Centre The British Heart Foundation

Background
Adherence to statin medication is sub-optimal among cardiac patients, but the reasons for this are multifaceted. Studies suggest that the perceptions held about one’s illness can impact the trajectory of recovery after an unheralded event like a myocardial infarction. However, there remains a paucity of longitudinal research examining change in illness perceptions and statin adherence over time.

Purpose
Investigation of this topic was crucial to ensure vital medications are adhered to following a life-threatening event. This could subsequently increase quality of life, lower hospital readmissions and pharmaceutical waste. Therefore, hypotheses were proposed to determine if illness perceptions and statin adherence changed over time, and whether illness perceptions were associated with and could predict statin adherence.

Methods
Participants between 30 and 90 years of age who presented with a first-time myocardial infarction were recruited by a research nurse using a convenience sample at an acute heart attack centre. 181 participants took part and completed the 8-item Morisky Medication Adherence Scale and the Illness Perceptions Questionnaire-Revised. The latter questionnaire measured identity (perceived nature of the condition), beliefs about illness cause, timeline (perceived illness duration), consequences of the illness, perceived control over one’s illness, understanding of one’s condition, and emotional representations (the impact the illness has emotionally). The questionnaires were presented before hospital discharge, and one and six months post-discharge. Statistical analyses were then performed on the collected data.

Results
Correlational analyses highlighted significant positive and negative associations between statin adherence and illness perceptions across the three timepoints (timeline, consequences, control, and emotional representations; p &lt; 0.05). Furthermore, a one-way repeated measures analysis of variance emphasised how the above-mentioned perceptions (along with identity) declined over time, as did statin adherence. Finally, standard multiple regressions accentuated how perceived control significantly predicted statin adherence (p = 0.02).

Conclusions
The findings highlight the influence of illness perceptions on statin adherence and may prove valuable for the design of holistic interventions which target dysfunctional perceptions. These could be delivered by health psychologists and subsequently increase adherence and condition self-management. Nevertheless, future research is warranted to examine the presence of other confounding variables. Larger sample sizes which encompass patients from around the United Kingdom should also be adopted to show whether the findings differ depending on condition and/or geographical location.