Patient adherence: an opportunity for improving cardiovascular disease outcomes

เยี่ยมชม a:care ครั้งแรกใช่มั้ย? ลงทะเบียนที่นี่




Patient adherence: an opportunity for improving cardiovascular disease outcomes


Key Messages 

  • The rapid increase in cardiovascular disease determinants,
    such as ageing, smoking, obesity and sedentary lifestyles are transforming healthcare needs in developing countries 
  • Global cardiovascular non-adherence rates are greater than 50% in developing countries, indicating a significant opportunity to improve healthcare outcomes
  • Low cardiovascular medication adherence is associated with significantly worse outcomes, including increased risk of mortality, morbidity and healthcare costs
  • Physicians can use a number of simple and efficient strategies to increase adherence

Cardiovascular Diseases Are Transforming Healthcare Needs.

Changing demographics and lifestyle trends are driving an unprecedented increase in the prevalence of chronic conditions, affecting nearly half of all adults and approximately 8% of children worldwide.1 Cardiovascular diseases pose a particular threat as the leading cause of mortality globally, and disproportionately affecting low- and middle-income countries.2 Cardiovascular disease determinants, such as population ageing, smoking and obesity, are manifesting dramatically in these countries.
For example, the proportion of the population over age 65 is expected to double in just two decades in Brazil, a phenomenon which took over a century in France.3 Amid these shifts, pharmacological treatments are increasingly important as effective disease management solutions but require adherence to be effective.

Non-adherence Among Cardiovascular Patients Is Significant, Even After Acute Events.

Adherence rates for cardiovascular treatments generally approximate the global adherence rate of 50%, meaning that roughly half of prescribed medications are not taken.4,5 Other studies indicate that adherence rates are even lower in developing countries.6 Even acute cardiac events do not necessarily improve adherence. Adherence rates are poor even among patients who have experienced an acute cardiac event. In a study of more than 4,500 post-myocardial infarction (MI) patients, 18% did not once fill their cardiac medications in the 4 months after discharge from hospital. And in a separate cohort of more than 22,000 post-acute coronary syndrome patients, 60% discontinued their statin medication within 2 years of hospitalization (non-persistence).7


Poor adherence is associated with worse outcomes and higher costs.

Low adherence is linked to poor control of cardiovascular disease risk factors such as hypertension and cholesterol. It is also associated with worse outcomes. For example, survivors of acute MIs who had poor and intermediate adherence to statins had 25% and 12% increased risk of mortality, respectively, compared to survivors with high adherence.7 These poor outcomes are associated with annual non-adherence costs as high as $19K per patient with cardiovascular disease.1 Given the magnitude of what is at stake in terms of outcomes and costs, the adherence challenge must be addressed.

Adherence Behavior is Complex, Making it difficult to evaluate and influence. 

Medication adherence is defined as "the degree to which the person’s behavior corresponds with the agreed recommendations from a health care provider." Adherence has three components, commonly referred to as fulfillment, persistence and compliance. 

-   Fulfillment refers to the prescription initially being filled by the patient. 
-   Persistence refers to the treatment being taken for the intended duration. 
-   Compliance refers to the extent to which a patient adheres to intended
     timing, dosage, and other indications for taking the medication.8

The complexity of patients’ behavior regarding their medication makes real adherence levels and adherence impact difficult to quantify. Quantitative measures for assessing adherence include the mean Medication Possession Ratio (MPR) and the Proportion of Days Covered (PDC).

-   Medication Possession Ratio is commonly defined as “the proportion (or percentage) of days’ supply obtained during a specified time period or over a period of refill intervals”. 
-   Proportion of Days Covered refers to the number of days when the drug was properly taken as a proportion of days in the observation period. 

“Adequate” adherence in the case of any individual patient is generally defined as a ratio of at least 80% for either of these measures.9

Adherence is complex but changeable. Maintaining high adherence levels requires that patients continuously make choices and adjust their behavior to overcome the various challenges to taking their treatment. 

Fortunately, behavioral science provides a variety of strategies that prescribers can use in real-world practice to increase patients’ adherence levels.

1. Cutler, Rachelle Louise et al. “Economic impact of medication non-adherence by disease groups: a systematic review.” BMJ open vol. 8,1 e016982. 21 Jan. 2018, doi:10.1136/bmjopen-2017-016982
2. “Cardiovascular Diseases (CVDs).” World Health Organization, World Health Organization, 17 May 2017,
3. Global Health and Aging. World Health Organization, 2011, p. 4, Global Health and Aging.
4. Forissier, Thomas, and Katrina Firlik. Estimated Annual Pharmaceutical Revenue Loss Due to Medication Non-Adherence. Capgemini Group, 2012, p. 7, Estimated Annual Pharmaceutical Revenue Loss Due to Medication Non-Adherence.
5. Brown, Marie T, and Jennifer K Bussell. “Medication adherence: WHO cares?.” Mayo Clinic proceedings vol. 86,4 (2011): 304-14. doi:10.4065/mcp.2010.0575
6. Hamine, Saee et al. “Impact of mHealth chronic disease management on treatment adherence and patient outcomes: a systematic review.” Journal of medical Internet research vol. 17,2 e52. 24 Feb. 2015, doi:10.2196/jmir.3951
7. Kronish, Ian M, and Siqin Ye. “Adherence to cardiovascular medications: lessons learned and future directions.” Progress in cardiovascular diseases vol. 55,6 (2013): 590-600. doi:10.1016/j.pcad.2013.02.001
8. Jimmy, Beena, and Jimmy Jose. “Patient medication adherence: measures in daily practice.” Oman medical journal vol. 26,3 (2011): 155-9. doi:10.5001/omj.2011.38
9. Anghel, Laura Alexandra et al. “An overview of the common methods used to measure treatment adherence.” Medicine and pharmacy reports vol. 92,2 (2019): 117-122. doi:10.15386/mpr-1201