Elsevier

Journal of Clinical Lipidology

Volume 13, Issue 1, January–February 2019, Pages 163-169
Journal of Clinical Lipidology

Original Article
Higher long-term adherence to statins in rural patients at high atherosclerotic risk

https://doi.org/10.1016/j.jacl.2018.11.004Get rights and content

Highlights

  • Long-term statin adherence is suboptimal in patients at high atherosclerotic risk.

  • Rural patients are significantly more adherent than urban patients.

  • Despite greater adherence, all-cause mortality is greater in rural populations.

  • Poorer access to health services and delayed diagnosis are likely contributory.

Background

Rural patients with atherosclerotic cardiovascular disease (ASCVD) experience greater cardiovascular morbidity and mortality than their urban counterparts. Statin therapy is a key component of ASCVD treatment. The extent to which there may be regional differences in long-term adherence to statins is unknown.

Objective

To assess long-term rates of adherence to statins in a high-risk ASCVD cohort, and whether regional differences exist between rural and urban patients.

Methods

Follow-up was conducted in patients who underwent coronary angiography at a single tertiary center between 2009 and 2013. Adherence was defined as consumption of prescribed statin ≥6 days per week. Patients were divided into remoteness areas (RAs), classified as RA1 (major city), RA2 (inner regional), and RA3 (outer regional) based on the Australian Standard Geographical Classification.

Results

Five hundred twenty-five patients (69% male, mean age 64 ± 11 years) were followed-up after a median of 5.3 years. Baseline characteristics were similar between RAs. Overall adherence was 83%; however, rural patients were significantly more adherent to their statin therapy (80% in RA1, 83% in RA2, and 93% in RA3, P = .04). Living in RA3 independently predicted greater statin adherence than living in RA1 (odds ratio: 2.75, 95% CI: 1.1–7.8, P = .03). All-cause mortality was significantly higher in RA3 than other regional areas (6% RA1, 12% RA2, and 18% RA3, P = .01).

Conclusions

Despite higher all-cause mortality, rural patients with ASCVD demonstrate significantly greater long-term adherence to statins than urban patients. Other factors, such as reduced access to health care and delayed diagnosis may explain the gap in outcomes between rural and urban patients.

Introduction

An established cardiovascular health disparity exists between rural and urban patients among many developed countries worldwide. Compared to their urban counterparts, rural patients have higher rates of cardiovascular mortality1 and inferior access to guideline-based care.2 Optimal medical therapy in these patients includes statins, and patient adherence is paramount for their substantial therapeutic benefit to be realized. Despite this, adherence to statins is known to be suboptimal and nonadherence confers a greater risk of recurrent myocardial infarction (MI)3 and mortality.4 Whether rural patients have poorer long-term adherence to statins is unknown. Studies comparing adherence rates in different regional settings have focused on other drug classes and have noted conflicting results. A pooled analysis of 3 studies5 found no difference between adherence to antihypertensive medications in rural and urban patients. In contrast, a large study6 in Canadian patients observed significantly greater adherence to multiple antihypertensive drug classes in rural patients. We therefore sought to determine (1) rates of long-term adherence to statins in patients with atherosclerotic cardiovascular disease (ASCVD) and (2) whether any regional differences exist and are predictive of adherence.

Section snippets

Patient cohort

Patients were identified from the Biomarkers of Atherosclerosis, Vascular, and Endothelial Dysfunction in Heart Disease (BRAVEHEART) study. The BRAVEHEART study is a prospective cohort study that recruited patients presenting for coronary angiography/percutaneous intervention (CA/PCI) to St Vincent's Hospital, Melbourne, between May 2009 and May 2013. Patients with the following were excluded: acute or chronic infections, systemic inflammatory conditions, recent or untreated malignancies, and

Baseline characteristics

The baseline characteristics of the patients are listed in Table 1. Five hundred twenty-five patients (69% male, mean age 64 ± 11 years) from the BRAVEHEART registry were contacted after a mean follow-up duration of 5.3 ± 0.9 years. Each RA was well represented with 34% of patients living in RA1, 45% in RA2, and 21% in RA3 (Fig. 2). Approximately 73% of patients had hypertension, 78% had dyslipidemia, 29% had diabetes mellitus, and 62% had a history of smoking. A substantial burden of ASCVD was

Discussion

Statins are considered a cornerstone of optimal medical therapy for patients at high ASCVD risk, and adherence is associated with reduced morbidity and mortality. In this prospective study in high-risk patients, 83% of patients overall were adherent to statins at a mean follow-up of 5.3 years. We observed that statin adherence increased in a stepwise manner with rurality, and living in outer regional areas independently predicted greater adherence. Our study is unique in that it assessed

Conclusion

Among high-risk ASCVD patients, adherence increased with remoteness, with patients living in outer regional areas reporting the greatest adherence rates. Living in a rural setting was a strong independent predictor of greater adherence; however, despite this, all-cause mortality was greater in rural areas. Living in a rural setting is not an impediment to adherence. However, other factors such as poorer access to health services, delayed diagnosis and management of ASCVD risk factors, cancers

Acknowledgments

Conflict of interests: The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Funding sources: Associate Professor Andrew M. Wilson is supported by grants from the National Heart Foundation of Australia, Australia and Diabetes Australia Research Trust, Australia. Dr Arul Baradi is supported by Australian Government Research Training Program and Centre of Research Excellence in Cardiovascular Outcomes Improvement

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