Medication Adherence

When I first started my social robotics project last year I had never heard of the phrase “medication adherence”. At the time I had something I wanted to build and launched into it. It wasn’t until a conversation I had with my doctor about what I was working on that he asked if I was forgetting to take my medication or if I had any “adherence” problems. After reassuring him that everything was OK (!) I wanted to know more. I started looking for publicly available research to get a better understanding and possibly some inspiration for projects outside of my own experiences.

Most of the research into adherence focuses on chronic diseases such as diabetes, hypertension, asthma etc. After reading plenty of literature and combined with my own experiences as well as those of other “Crohnies” I’ve talked to over the years, the theory of it all still very much applies to Crohn’s Disease.

For the record a chronic disease has “one or more of the following characteristics: they are permanent, leave residual disability, are caused by non-reversible pathological alteration, require special training of the patient for rehabilitation or may be expected to require a long period of supervision, observation or care” [1].

What is “medication adherence”?

It is conceptually about eliminating the barriers that may interfere with the treatment plan for a patient with a chronic disease. Originally referred to as “compliance” where the patient was solely to blame for being “non compliant”. It was defined as “the extent to which the patient’s behaviour (in terms of taking medications, following diets or executing other lifestyle changes) coincides with clinical prescription” [2].

Over several decades researchers came to understand that while observed as a behavioural problem in patients, the roots of the problem often exist beyond the patient and are often outside of their control [1].

In 2003 the World Health Organisation (WHO) defined adherence as “the extent to which a person’s behaviour – taking medication, following a diet, and/or executing lifestyle changes – corresponds with agreed recommendations from a health care provider” [1].

The Components of Adherence

In 2012 the EU identified the need to reduce the potential interpretations of adherence and improve understanding through common terminology. Through consensus they agreed on the following terms:

  • Initiation – when a patient takes the first dose of their prescribed medication.
  • Implementation – is the extent to which a patient’s actual dosing corresponds to the prescribed dosing regimen, from initiation until the last dose.
  • Persistence – is the length of time between initiation and the last dose, which immediately precedes discontinuation.
  • Discontinuation – when a patient stops taking their prescribed medication, for whatever reason(s).

Why is adherence so important?

Aside from the obvious worsening of symptoms, non-adherence increases the likelihood of diminished or total loss of medication efficacy, avoidable diagnostic testing and otherwise unnecessary surgical procedures. Patients may also suffer loss of income, psychological and emotional distress, diminished quality of life and negatively impacted social or familial situations. It’s estimated that poor adherence is responsible for as many as 200,000 premature deaths in the European Union a year [4].

Unnecessary strain is put on secondary healthcare services such as outpatient clinics, Accident and Emergency (A&E) departments, and medical laboratories. In the EU approximately EUR 125 billion a year in extra healthcare service costs are attributed to poor adherence. In the United States it’s estimated that USD 105 billion is lost annually to avoidable hospitalisations caused by poor adherent behaviour [4].

Considering that a patient with a chronic disease spends less than 0.1% of their time with a medical professional [5] and that pharmaceutical expenditure is reportedly the third largest part of total health care expenditure (after hospital and ambulatory care) among EU Member States [3], addressing the issues that cause poor adherence is crucial.

Factors that impact adherent behavior

The WHO identified the following five major factors that can impact a patient’s ability to be adherent.

  • Socioeconomic – e.g. poverty, unstable living conditions, high medication costs, lack of effective social support networks, long travel distances to treatment centres, cultural beliefs about illness.
  • Health system & health care team – e.g. poorly developed services, lack of continuity of care, inadequate reimbursement by health insurance, little to no information sharing between clinics and pharmacies, overworked healthcare providers, short consultation times, lack of knowledge of adherence, poor capacity to educate patients.
  • Therapy related – e.g. complexity of treatment regimen, adverse side effects, immediacy of beneficial effects, duration of treatment.
  • Condition related – e.g. severity of symptoms, level of disability, progression of disease, availability of effective treatments, co-morbidities.
  • Patient related – e.g. motivation, knowledge of illness, self-efficacy, treatment outcome expectations, forgetfulness, fear of stigmatization, anxiety, frustration, lacking in skills to manage symptoms.

 Types of non-adherence

To date there is no typical non-adherent personality nor is there a set of characteristics that would be predictive of poor- or non-adherent behavior. It is possible to define the types of non-adherent behavior however. They are:

  • Erratic – The most common type of non-adherence [1]. The patient understands their treatment regimen and desires to adhere. However they may be forgetful, have an unpredictable schedule or a busy lifestyle that interferes with their adherence.
  • Unwitting – A patient may not fully understand the specifics of their treatment, disease or the necessity for adherence [1]. They may have forgotten instructions given to them or misinterpreted them. For example, “take twice daily” is misunderstood as “take twice daily but only if you have symptoms”.
  • Intentional – A patient will deliberately alter, discontinue or even fail to begin their treatment [1]. Failure to begin is often referred to as “primary non-adherence” [4]. This decision reflects a reasoned choice on the part of the patient. They may have fears of short- and long-term side effects or believe they do not need to renew or continue their prescription (known as “secondary non-adherence” [4] or “non-persistence” [3]). Interference with their daily life may convince a patient the negatives of their treatment outweigh the benefits.

Can adherence be measured?

It is quite challenging to accurately and reliably measure adherence or more precisely, non-adherence. A combination of the following types of measurement were suggested by [3]:

  • Subjective – physicians can ask the patient, caregivers or family members about the patient’s medication use (using a tool such as the “Morisky Medication Adherence Scale” [6]) and record the results.
  • Observational – counting pills, verifying pharmacy prescription records or using electronic medication event monitoring systems (MEMS).
  • Biochemical – blood, urine or serum level tests to identify the presence of prescribed medication or related chemicals.

These methods all have their flaws. Lies can be told about medication use, pill counting does not mean they were taken, IT systems are required for certain technological options, and knowing a blood test or procedure is scheduled can lead patients to start temporarily taking their medication again (sometimes referred to as “white-coat adherence”).

What could be done to improve adherence?

The WHO and EU made recommendations that all stakeholders – patients, their families, care givers, physicians, nurses, clinicians, pharmacists, educators, hospitals, pharmaceutical companies and governments – should be invested in ensuring the best possible clinically and cost effective strategies are utilised.

Behavioural Science

Behaviour change is a key element to ensuring adherence. The WHO suggested a “states of change” (SOC) model from the field of behavioural sciences. It identifies five stages that a person progresses through as they intentionally change their behaviour.

  • Precontemplation – no changes intended in the next 6 months.
  • Contemplation – considering making changes in the next 6 months.
  • Preparation – planning to change behaviour in the next 30 days.
  • Action – currently changing behaviour.
  • Maintenance – successfully made changes for at least 6 months.

The “states of change” model helps to characterise a patient at different levels of their “readiness for change” [1]. SOC has proven useful by providing actionable strategies at different levels of readiness to help people change behaviour. These strategies utilise some key psychological constructs:

  • Decisional balance – whether the pros of “healthy behaviour” outweigh the cons. The pros are low in the early stages of change and increase as the stage of change increases. Conversely the cons are high and decrease as the stage of change increases.
  • Decisional balance is a very useful indicator of a person’s readiness to move out of the precontemplation stage. Helping a patient to identify the pros and cons is vital when they are in the early stages of change (precontemplation, contemplation and preparation).
  • Temptation to relapse – the temptation to engage in “unhealthy behaviour” is often highest at the precontemplation stage and tends to decrease linearly from precontemplation through to maintenance. It is an important indicator of levels a patient’s level of confidence in their ability to self-manage their behaviour.
  • Strategies for change – associated with successful progression from one stage to the next these can be divided into “experiential” and “behavioural” and used to aid a patient in particular stages of change.
    • Experiential strategies – are aimed at an individual thinking about change and so reflect cognitive, evaluative and affective planning for change.
    • Behavioural strategies – emphasise observable change strategies such as rewards and reminders.

Governments and Policy makers

Making medication adherence a priority is the number one requirement at this level. Investment should be made to research the best clinically and cost effect methods of intervention as well as in providing targeted training for undergraduate and postgraduate healthcare providers to enable them to identify non-adherence and manage medication adherence.

The Healthcare System

Medication adherence support should be included in the design of services, organisations and internal systems. Medical staff should be provided with professional training that includes theoretical and practical elements in the identification of non-adherence and management of medication adherence. Every contact point a patient has with their healthcare system should be working towards the goal of preventing poor or non-adherence.

Healthcare Professionals

The reliance on the “biomedical model” [1] that focuses on the relationship of disease to treatment is insufficient and behavioural theories should also be considered. It’s an incorrect assumption that their condition should be motivation enough for a patient to be adherent.

Patients should be made a partner in the decision making process. A trusting and “blame free” environment should be fostered where patients feel comfortable raising concerns or problems. Treatment should be inclusive of the patient’s preferences, beliefs, and their life (daily habits and routines) outside of their disease.

Interventions should target the initiation, implementation and persistence components of medication adherence and be prioritised when:

  • Any medication is newly prescribed
  • Changes to treatment or dosing are considered
  • More than one medication is prescribed
  • Agreed treatment goals are not met
  • Adverse reactions are anticipated or experienced
  • Any time a patient requests assistance with medication taking


Patients should be provided with education and information to increase their knowledge of their disease and treatment options. Support should be provided to aid patients in developing the necessary psychological, motivational or behavioural skills as information is often useless if patients lack the abilities to act upon it. Where appropriate treatment based goals should be set and motivational or performance related feedback be provided.

In summary

Keep a watch…on the faults of the patients, which often make them lie about the taking of things prescribed. For through not taking disagreeable drinks, purgative or other, they sometimes die.” – Hippocrates, Decorum.

“Drugs don’t work in patients who don’t take them” – C. Everett Koop, MD, former US Surgeon General (1985).

Medication adherence has been a known issue since Hippocrates wrote about it in the 4th century BC. The complexity of it is clearly indicated by the fact it continues to be such a serious problem in modern healthcare.

Almost everyone required to self-manage care long term will have an issue with non-adherence. There are no typical personality characteristics that will predict when a patient will not adhere to their treatment. Regular monitoring at the patient and system level as well as making adherence a national health policy priority could help to reduce both the problem and the associated costs.

Unfortunately, there is no perfect framework or model, but tailored interventions are better than non-tailored ones and multi-level are more successful [1]. Using erratic non-adherence as an example a tailored multi-level intervention would be as simple as their physician discussing the patient’s lifestyle or work requirements and figuring out the best possible dosing regimen for them to follow.

It’s vital to acknowledge that treatment of chronic life long illness occurs across the spectrum of disease fluctuations, the complexity of the patient’s life, insurance costs, hospital budgets, national health policies and political wrangling.

A personal observation

My treatment to date has predominantly been of the “biomedical” variety. It was always blood test results, scopes, scans, medication, and questions about physical pain. I’m not complaining at all, just making an observation. That’s what was available to me and it’s what helped get me into remission.

In some cases I was warned by my doctor that a particular medicine might make me motion sick (azathioprine!) or I might experience mood swings and a ravenous appetite (steroids!). It wasn’t an option to not to take the medicine. If I wanted to get better it’s what I had to do.

It was a stroke of good fortune to get a regular Friday slot for infusions because I would be so wiped out for most of the following Saturday that going into work would have been very tough. I would probably have ended up taking two days off – one for the infusion and one for recovery.

I am definitely guilty of the first two types of non-adherence. If any of my doctors read this, I swear none of it lasted for very long! For the first few years it was a very hard routine to follow – waking up (feeling exhausted) with enough time to take tablets that had to be taken before food, often forcing myself to then eat breakfast so I could take the tablets that had to be taken with food, taking tablets that were foul tasting, tablets that made me feel like I’d vomit, and then getting on a bus to work. Taking more tablets during the day and then again at night. There were so many different tablets to be taken at one point it reminded me of this quote:

“I don’t do drugs. I am drugs” – Salvador Dali

Reading through the various reports it was easy to see what has been lacking in the healthcare systems I’ve been an outpatient in since my diagnosis. As I was going through the recommendations from the WHO and the EU I couldn’t help but think “Where on Earth are the resources for any of this?”. It is very easy to get angry about the continued deterioration of the Irish healthcare system. I don’t know how things would have turned out for me if I had to go to A&E now in the same dire state I was in in 2006.

Update: I should have also included my experiences with pharmacies as they are part of the healthcare system and haven’t always helped me maintain my adherence. The majority of the time I have not had serious issues but there have been more hassles and frustrations than should be necessary. For example:

  • When going to get a prescription filled at a particular chain I was told my doctor was wrong and a tablet on my prescription wasn’t “being produced” anymore. I decided I’d try another pharmacy and it turned out the tablets were very much still in production. When I told that pharmacist of what I’d been told in the previous pharmacy, her reply was basically “you were lied to, that chain don’t make enough money selling those tablets and that’s why they told you that”. I’ve had friends with regular prescriptions tell me the similar things or their regular medication suddenly isn’t available and, surprise! surprise!, a slightly more expensive one is.
  • There’s a particular tablet I take 3 of every day. I’m prescribed 90 of them by my doctor. The pharmacy sells them in boxes of 28, so they would only ever give me 3 boxes per month unless I hassled them for the remaining amount. They didn’t want to give them to me because it would mean having to open another box in order to get the remaining 6 tablets.
  • Prescription renewal systems that can’t handle “5 week” months. So if you inject adalimumab, for example, every 2 weeks then in a “5 week” month that means 3 injections. However the pharmacy claims they can’t manage that and will only prescribe 2.

References and Bibliography

[1] – “Adherence To Long Term Therapies”, WHO, 2003

[2] – “Compliance with therapeutic regimens”, Sackett DL, Haynes BR., Baltimore, John Hopkins University Press, 1976

[3] – “Ascertaining Barriers for Compliance: policies for safe, effective and cost-effective use of medicines in Europe”, EU ABC Project, 2012.

[4]- “Investing in Medication Adherence Improves Health Outcomes And Health System Efficiency”, OECD, 2018

[5] – “Beyond the fog: a future for public healthcare”, Royal Free Charity, 2018

[6] – “Concurrent and predictive validity of a self-reported measure of medication adherence”. Med. Care. 1986;24(1):67–74, Morisky DE, Green LW, Levine DM.

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