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 Table of Contents  
Year : 2017  |  Volume : 3  |  Issue : 1  |  Page : 8-10

Medication adherence: Adjunct to patient outcomes

Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India

Date of Web Publication17-Jul-2017

Correspondence Address:
Pooja Singh
Room No. 4046 D, Teaching Block, 4th Floor, All India Institute of Medical Sciences, New Delhi
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jpcs.jpcs_10_17

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Adherence to a medication regimen is generally defined as the extent to which patients take medications as prescribed by their health care providers. Approximately 50% of patients do not take their medications as prescribed. Factors contributing to poor medication adherence include those that are related to patients (eg., suboptimal health literacy and lack of involvement in the treatment decision–making process), those that are related to physicians (eg., prescription of complex drug regimens, communication barriers, ineffective communication), and those that are related to health care systems (eg., limited access to care). Because barriers to medication adherence are complex and varied, solutions to improve adherence must be multifactorial.

Keywords: Adherence, cardiovascular disorders, medication

How to cite this article:
Singh P. Medication adherence: Adjunct to patient outcomes. J Pract Cardiovasc Sci 2017;3:8-10

How to cite this URL:
Singh P. Medication adherence: Adjunct to patient outcomes. J Pract Cardiovasc Sci [serial online] 2017 [cited 2023 Mar 20];3:8-10. Available from: https://www.j-pcs.org/text.asp?2017/3/1/8/210854

  Introduction Top

Medication adherence has been defined as “active, voluntary, and collaborative involvement of the patient in a mutually acceptable course of behavior to produce a therapeutic result.”[1] The World Health Organization (WHO) definition of adherence is: “… the extent to which a person's behavior – taking medication, following a diet, and or executing lifestyle changes – corresponds with the agreed recommendations from a provider.”

Adherence to medication has been studied for long, as a determining factor in the management of treatment outcomes, particularly for chronic diseases.

Medication nonadherence, being an unforeseen and an emerging problem in health-care systems, the cost incurred due to nonadherence to medications often exceeds the health-care costs including the cost of management of complications arising due to nonadherence. The terms adherence, compliance, and persistence have been used interchangeably. Adherence has been studied as a combination of persistence and compliance where persistence refers to the duration of drug use, and compliance is a subjective statement of patients' behavior toward prescribed medication.

Nonadherence is a well-known factor leading to worsening of the clinical condition in cardiovascular disorders. Recent studies aimed at improving medication adherence in cardiovascular patients have shown promising results in the improvement of treatment outcomes.[2]

White coat adherence is commonly encountered in clinics and refers to nonadherent patients improving their medicine-taking behavior during the time nearing their physician visit, being a bias in improving short-term outcomes but does not have a significant effect on long-term outcomes.[2]

Poor medication adherence can lead to:

  • Unnecessary disease progression and complications
  • Reduced functional abilities and quality of life
  • More medical costs and physician visits
  • Increased use of expensive, specialized medical resources
  • Unneeded medication changes.

  Measurement of Medication Adherence Top

1. Subjective measurements: Questionnaire based approach in asking patients about their medicine-taking behavior.

A number of questionnaires have been used by researchers in this regard including:

  • Morisky Medication Adherence Scale
  • Self-efficacy for Appropriate Medication Use (SEAMS)
  • Brief Medication Questionnaire (BMQ)
  • The Hill-Bone Compliance Scale
  • Medication Adherence Rating Scale (MARS)
  • Adherence to Refills and Medications Scale (ARMS)
  • Scale for measurement adherence to medication applied in Zagreb, Croatia (Culig).

Being cheap, easy to administer, non-intrusive, and able to provide information on attitudes and beliefs about medication self-reported measurement is most widely used, though the inability to understand the items, and non-willingness to disclose information, can affect response accuracy and limits their use.

2. Objective measurements: Pill counts and electronically monitored medication adherence has shown promising and validated the direct measurement of patient medication adherence patterns through:

  • Counting pills/examining pharmacy refill record
  • Electronic medication event monitoring systems (MEMS).

Measurement adherence ratio calculated with pill counts is given by the formula:

MEMS allow most precise adherence measurement, but the cost concerns are high. It involves the use of microprocessors inserted into the cap of the medication container which records the date and time, assuming that the patient has taken medicine. Although possessing accuracy, limitations of MEMS use involve bulkiness of the container, incorrect use of the caps by the patients, high costs and coordination of personnel and systems required.

In a study using this system, it was found that >88% medication adherence to heart failure medication, especially angiotensin-converting enzyme inhibitors and beta blockers lead to better outcomes.[3]

3. Biochemical measurements:

  • Adding a nontoxic marker to the medication
  • Detecting its presence in blood or urine
  • Measurement of serum drug levels.[1]

Healthy adherer effect evidenced by improved treatment outcomes in patients who otherwise follow prescribed lifestyle and treatment interventions has been observed in heart failure patients. Patients who take their medicines regularly are more likely to be adherent to lifestyle measures and have improved disease conditions.

  Medication Adherence in Cardiovascular Disease Top

Poor medication adherence is common among patients with cardiovascular disease. Studies suggest that 24% patients' post cardiac event do not fill their prescriptions within 7 days of discharge and 34% of patients stop taking their medicines within 1 month of discharge.[4] Among cardiovascular medications, self-reported medication adherence was found to be 83% for an aspirin, 63% for lipid lowering agents, 61% for beta blockers, 54% for aspirin + beta blockers, and 39% for beta blocker + aspirin + lipid lowering agents. Despite the proven efficacy and safety profile of pharmacological agents in hypertension, 50%–80% of patients are not adherent to prescribed therapy. Due to this failure to achieve blood pressure control, there is an increased risk of myocardial infarction (MI) and stroke[5] leading to increased mortality and hospitalization. Adherence to antihypertensive therapy has shown benefit in reducing worsening of cardiac condition.[6] In post-MI patients, filling all of the prescription medications within 120 days was found to be associated with lower odds of death as compared with those who filled their prescriptions partially.[7]

Barriers to medication adherence in heart failure patients as evidenced by existing literature include complex medication regimes (71%), running out of medications (33%), and adverse drug reactions (20%). Interventions involving patient health education and counseling (100%), reduction in dose frequency (32%), and introducing dose administration aids (15%) have shown to improve medication adherence, hospital readmissions, the average length of stay for readmissions and deaths due to chronic heart failure.[8]

Several interventions to improve medication adherence have been tried. These can be described as:

Health system related:

  • Team-based approach:
    • Training nonphysician staff to perform duties traditionally completed by physicians like an assessment of nonadherence by the patient which allows the physician more time to discuss the patient's medication adherence patterns
    • Assessment of nonadherence by office staff and pharmacists, pharmacist-based patient education, phone call reminders, Web-based tools, and assignment of a case manager.


  • Need for “shame-free” environment
  • Pictorial and audiovisual educational material instead of written instructions
  • Recognizing and treating mental illness must be a priority when treating patients with other chronic conditions
  • Recognizing that patients' economic constraints will limit their ability to adhere
  • The physician may direct patients to programs that provide financial assistance
  • A hospital social worker, practice champion, or community center volunteer may offer the time and resources necessary to assist individual patients.


If physicians are aware that patients plan to ration their medication, they will be able to discuss the importance of taking the medication as directed or to prescribe a different medication that is more “forgiving.”


  • Establishing social support
  • Defining new health-care policies to improve adherence
  • Employment of resources and workforce for improving individual medication adherence.

Health-care costs among nonadherent and adherent patients have been reported as similar. Patients with drug benefit caps are more likely to be nonadherent to medications for hypertension, hyperlipidemia, and diabetes and have worse outcomes. Studies have shown a graded relationship between the level of copayment and medication adherence, with patients more likely to refill medications that had a lower copayment.[1]

The cost of medical therapy has been a matter of concern for various investigators in achieving adherence to medications. Especially in a developing country like India, medication costs impose a significant burden for patients as well as health-care authorities. A study was done to see whether copayments have any influence on medication adherence in chronic heart failure patients. Copayments were considered when patients were financially aided in the procurement of medicines either from the government, employer, or insurance companies. The results suggested no significant correlation between the presence of copayment and medication adherence. A literature study comparing adherence and cost sharing concluded that higher cost sharing was associated with poorer adherence outcomes.[9] Another study in heart failure patients reflected higher copayments resulting in poorer adherence.[10]

The need of the hour is having a collaborative and dedicated involvement of patient, physician, pharmacists and health-care professionals in bringing adherent patients with better clinical outcomes. Having adherent patients would be a worthy goal in getting maximum benefit out of prescribed therapies. Several studies have reported that in chronic illness, patients have difficulty in adhering to recommended regimen. As the former Surgeon General C. Everett Koop reminded us, “drugs don't work in patients who don't take them.” Physicians should recognize that poor medication adherence contributes to suboptimal clinical benefits, increasing adherence may have a greater effect on health than any improvement in specific medical treatments. The multifactorial nature of poor medication adherence implies that only a sustained, coordinated effort will ensure optimal medication adherence and realization of the full benefits of current therapies.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Ho PM, Bryson CL, Rumsfeld JS. Medication adherence: Its importance in cardiovascular outcomes. Circulation 2009;119:3028-35.  Back to cited text no. 1
Brown MT, Bussell JK. Medication adherence: WHO cares? Mayo Clin Proc 2011;86:304-14.  Back to cited text no. 2
Wu JR, Moser DK, De Jong MJ, Rayens MK, Chung ML, Riegel B, et al. Defining an evidence-based cutpoint for medication adherence in heart failure. Am Heart J 2009;157:285-91.  Back to cited text no. 3
Ho PM, Spertus JA, Masoudi FA, Reid KJ, Peterson ED, Magid DJ, et al. Impact of medication therapy discontinuation on mortality after myocardial infarction. Arch Intern Med 2006;166:1842-7.  Back to cited text no. 4
Law MR, Morris JK, Wald NJ. Use of blood pressure lowering drugs in the prevention of cardiovascular disease: Meta-analysis of 147 randomised trials in the context of expectations from prospective epidemiological studies. BMJ 2009;338:b1665.  Back to cited text no. 5
Jimmy B, Jose J. Patient medication adherence: Measures in daily practice. Oman Med J 2011;26:155-9.  Back to cited text no. 6
Jackevicius CA, Li P, Tu JV. Prevalence, predictors, and outcomes of primary nonadherence after acute myocardial infarction. Circulation 2008;117:1028-36.  Back to cited text no. 7
Toh CT, Jackson B, Gascard DJ, Manning AR, Tuck EJ. Barriers to medication adherence in chronic heart failure patients during home visits. J Pharm Pract Res 2010;40:27-30.  Back to cited text no. 8
Eaddy MT, Cook CL, O'Day K, Burch SP, Cantrell CR. How patient cost-sharing trends affect adherence and outcomes: A literature review.PT 2012;37:45-55.  Back to cited text no. 9
Cole JA, Norman H, Weatherby LB, Walker AM. Drug copayment and adherence in chronic heart failure: Effect on cost and outcomes. Pharmacotherapy 2006;26:1157-64.  Back to cited text no. 10

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