This article describes the prevalence and implications of medication non-adherence. It focuses on the factors that can impact adherence and how awareness of these factors can help the hospital pharmacist to devise tailored strategies for use with their patients
Medication adherence can be defined as the extent to which patients are able to follow the recommendations for prescribed treatments.1 There are many other terms including concordance, therapeutic alliance and medication compliance, the latter of which has fallen from favour. As healthcare professionals, pharmacists are generally pro-medication and convinced of the relative benefits of therapy versus the relative risks. A study published in the British Medical Journal examined the correlation between adverse outcomes in patients following myocardial infarction – association with statin adherence and lipid targets – and found that those with adherence <50% had an increased risk of not meeting low-density lipoprotein levels ≤1.8mmol/l (adjusted odds ratio (OR) 2.03, 95% CI 1.78–2.31, <0.0001). The authors concluded that non-achievement of lipid and adherence targets were associated with increased risks of all-cause and cardiovascular disease mortality.2 It is thought that non-adherence contributes to the premature deaths of 200,000 Europeans per year.3 The financial cost of non-adherence is also substantial. In the UK, this was estimated to be of the order of £500 million annually.4
The questions from patients: “Will this medicine help me?” and “Will this medicine harm me?” oddly have the same answer. This is “Yes, but only if you take it”, and this is the crux of the issue. We know as pharmacists that millions of Euros are spent on research and development of a new drug. It will go through all phases of clinical trials, and gathering safety, efficacy, and long-term data, and yet when this medicine is prescribed and dispensed, the final stage, that is, the administration, becomes the ultimate determinant of its therapeutic success.
Every medicine, including placebos, have side effects and as medicines experts, pharmacists are aware that the benefit : risk ratio is heavily weighted in favour of the former and that only an acceptable level of risk would result in successful registration by Regulatory bodies. The lay person, however, is not necessarily aware or informed of this, and this can lead to misinformation or disinformation that might affect the willingness of the person to take the medicine at all (non-adherent) or take it as directed (partially non-adherent). A patient can be termed ‘non-adherent’ in two ways: namely, intentionally, or unintentionally. Arguably it is easier to mitigate against the unintentionally non-adherent patient as generally we know that this person has accepted the necessity of the medication over the risks that this might pose, and could for another reason, for example, poor memory, not be able to reliably take this medicine as directed.
Strategies to help with this tend to be quite straightforward and examples include memory aids, blister packing and text reminders to help patients manage their medicines.
However, the situation might be less straightforward: think of the patient who has suffered a stroke, for example. After the stroke, the patient might experience aphasia or dysphagia and therefore will require the expertise of a hospital pharmacist to undertake a medicines reconciliation. In this medication reconciliation, the pharmacist will have to assess each drug individually and determine its appropriateness to be crushed/ chewed/mixed with food/fluids, in line with best practice.5 In other words, they are optimising the medication for this patient by tailoring the drug regimen to align with the patient’s unique requirements.
There can also be an impediment ability of the patient to access the medicines; for example, an adult with rheumatoid arthritis who might have difficulty opening the medicine container. Again, here there is an opportunity for a hospital pharmacist to discuss medicine challenges with the patient prior to discharge and liaise with colleagues in the community to put the medicines in easy open containers.
By far the more complex and, as a researcher I would say, the more interesting phenomenon is the patient who has ‘decided’ to be intentionally non-adherent. The decision might not be a conscious one, but rather due to the number of different variables that are involved in the decision-making process. It might be sub-conscious: either way, the effect is the same – the patient will not take the medication as prescribed.
Factors affecting medication-taking behaviour
What are the factors that can negatively or positively impact upon medication-taking behaviour? When referring to behaviour, we must consider the capability, opportunity and motivation that ultimately leads to the behaviour. This is known as the COM-B model.6
There are many facets to capability, some above include the physical capability, psychological capability, but others may not be quite so obvious, there is the financial capability. Can the patient afford these medicines, particularly if they are for a chronic disease/disorder and especially if the disease is not interfering with their daily life? An example here would be type 2 diabetes mellitus. Having elevated blood glucose levels and how this will relate to cardiovascular health in five years can be an abstract concept and is in direct contrast to someone who is experiencing pain and needs pain relief immediately. Evidence shows that where the course of treatment is shorter the adherence is likely to be higher and vice versa. In 2003, it was estimated that only half of those who suffer with chronic conditions take their medications as prescribed, making medication adherence improvement a priority of the public health agenda.7 A 2019 study conducted on adherence to medicines for those with chronic conditions had similar findings and concluded that the proportion of adherent patients to treatment was 55.5%. Older age (adjusted OR1.31 per 10-year increment, 95% CI 1.01–1.70), lower number of pharmacies used for medication refills (0.65, 95% CI 0.47–0.90), having received complete treatment information (3.89, 95% CI 2.09–7.21), having adequate knowledge about medication regimen (4.17, 95% CI 2.23–7.80), and self-perception of a good quality of life (2.17, 95% CI 1.18–4.02) were independent factors associated with adherence.8
In addition, the perception of the need for this medicine must be higher that the perceived inconvenience/financial burden that this imposes. Although there are differences in how people pay for their medicines throughout Europe, and the mechanisms by which they could avail of reduced cost/free medicines, this also requires a capability on the part of the patient. To help with this, a hospital pharmacist might be able to liaise with their community pharmacy colleagues to enable the correct paperwork to be submitted/completed for the patient so that there is a seamless transition from one care setting to the next.
Health literacy has recently been redefined to take account of the personal health literacy, that is, the degree to which individuals have the ability to find, understand, and use information and services to inform health-related decisions and actions for themselves and others; and organisational health literacy, that is, the degree to which organisations equitably enable individuals to find, understand, and use information and services to inform health-related decisions and actions for themselves and others.9 Again there is a potential role for the pharmacist to engage with the patient and provide education and counselling and answer questions related to medicines. What is interesting here, however, is the subtle shift from a previous definition which included reference to the patient being able to make ‘appropriate’ health decisions to now being able to make an ‘informed’ decision. This reflects the growing acknowledgement of personal autonomy despite evidence-based information. This is likely a challenge for pharmacists (among others) as we are trained to understand and question the science and, having robustly tested it, we are likely to accept the conclusions. An example of this is the current pandemic in which we see people termed ‘vaccine hesitant’; this can evoke a lot of disbelief and frustration on the part of those pro-vaccination. It is, however, a huge opportunity for pharmacists to discuss these sincerely held beliefs with the patient and to engage in a dialogue whereby mis-/disinformation can be challenged. When we consider someone taking medicine, we must also consider this in the context of their individual beliefs, culture, faith, and many other factors. Some important work was carried out by Robert Horne and colleagues as far back as 1999, and resulted in the development of the Beliefs About Medicines Questionnaire.10 The theory underpinning this is that each person will have a set of beliefs relating to medicines in general, and specific medicines. The degree of positivity to which people respond to the individual statements gives an indication of their likelihood to take these medicines and can be a starting point for a conversation between the pharmacist and the patient.
With regards to opportunity, the first word that comes to mind is ‘access’ and access to medicines and medicines information is not equitable in Europe today. The greater the capability and opportunity the more likely a behaviour is likely to occur. Pharmacists who are working in hospitals encounter people with differing ages, incomes, native languages, levels of education, faiths, ethnicities, and political backgrounds. Awareness that health information, access to services, and specifically access to medicines, is not equitable is of huge importance to the help that pharmacists can provide. In your setting there may be one thing that you can do to try and balance this inequity. Important work has been done by many organisations and one of these is the National Adult Literacy Agency, based in Ireland.11 This is a useful resource to give information on how we as healthcare professionals can communicate more clearly with our patients and contains insightful videos from the perspective of the patient. Similarly, organisations in the UK, including the British Heart Foundation, have recognised that having the patient at the centre of what we do leads to better outcomes. They have produced a guide on 16 ways we can improve communication with patients.12
This is the key driver for many patients who do not adhere, either fully or at all, with the prescribed course of treatment. In my experience, many patients are not always sure of the ‘why’ of treatment. What is the want or the need for me to engage in this behaviour? For the hospital pharmacist, specifically, a patient being discharged back to the community setting is an ideal chance to engage with the patient regarding changes to their medication. An Israeli study in 2005 that examined the knowledge of medicines of 341 patients upon discharge demonstrated that although 73% knew the indication for their medicine, they still lacked knowledge regarding side effects, necessary lifestyle changes, and correct dosing frequencies. This study concluded that the only factor that positively affected levels of correct knowledge was whether the patient had received medication counselling during their hospital stay.13 While the resource implications of counselling each patient and ensuring an accurate discharge prescription can be considerable, this should be weighed against the substantial costs associated with unplanned readmissions.14
In conclusion, hospital pharmacists are uniquely placed to have a positive impact upon medication adherence in their patients. The combination of their specialised skillset and in-depth knowledge of medicines means that they can tailor the information and guidance to the needs of the individual patient.
- Vrijens B et al. A new taxonomy for describing and defining adherence to medications. Br J Clin Pharmacol 2012;73(5):691–705.
- Brown R et al. Associations of statin adherence and lipid targets with adverse outcomes in myocardial infarction survivors: a retrospective cohort study. BMJ Open 2021;11(9):e054893.
- van Boven JFM et al. Urging Europe to put non-adherence to inhaled respiratory medication higher on the policy agenda: a report from the First European Congress on Adherence to Therapy. Eur Respir J 2017;49(5):1700076.
- Action on medicine wastage and improving medicine use [Internet]. GOV.UK. www.gov.uk/government/news/action-on-medicine-wastage-and-improving-medicine-use (accessed January 2022).
- Oral Dosage Forms That Should Not Be Crushed [Internet]. Institute For Safe Medication Practices. www.ismp.org/recommendations/do-not-crush (accessed January 2022).
- Michie S, van Stralen MM, West R. The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implement Sci 2011;6(1):42.
- Sabaté E. Adherence to long-term therapies: evidence. https://scholar.google.com/scholar_lookup?title=Adherence+to+Long-Term+Therapies:+Evidence+for+Action&author=E.+Sabat%C3%A9&publication_year=2003& (accessed January 2022).
- Fernandez-Lazaro CI et al. Adherence to treatment and related factors among patients with chronic conditions in primary care: a cross-sectional study. BMC Fam Pract 2019;20(1):132.
- Centers for Disease Control and Prevention. What is health literacy? Take action. Find out. [Internet]. 2021 www.cdc.gov/healthliteracy/learn/index.html (accessed January 2022).
- Horne R, Weinman J, Hankins M. The beliefs about medicines questionnaire: The development and evaluation of a new method for assessing the cognitive representation of medication. Psychol Health 1999;14(1):1–24.
- National Adult Literacy Agency. Health literacy [Internet]. www.nala.ie/health-literacy/ (accessed January 2022).
- British Heart Foundation. 16 ways to improve your communication skills with patients [Internet]. www.bhf.org.uk/for-professionals/healthcare-professionals/blog/16-ways-to-improve-your-communication-skills-with-patients (accessed January 2022).
- Kerzman H, Baron-Epel O, Toren O. What do discharged patients know about their medication? Patient Educ Couns 2005;56(3):276–82.
- Uitvlugt EB et al. Medication-Related Hospital Readmissions Within 30Days of Discharge: Prevalence, Preventability, Type of Medication Errors and Risk Factors. Front Pharmacol 2021;12:567424.