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Speaker Spotlight: Professor John Weinman

John Weinman is Professor of Psychology at Kings College London. He’s part of the panel discussion My medicine and me: half the medications prescribed in the UK are never taken – why don’t we take our medicines and what can be done?


Cambridge Festival: What are some of the most common reasons people don’t take their prescribed medicines, either intentionally or non-intentionally?

John Weinman: There are many reasons, but these can be grouped into three main factors namely Capability, Opportunity and Motivation.  

  • Capability describes all those factors involving the individual’s psychological abilities (eg knowledge; understanding, memory, planning ability etc) and physical abilities (eg dexterity, strength) which can influence how easily they can take their medicines.  
  • Opportunity describes all those factors outside the individual that can influence whether they take their medication. It includes social factors such as the support they get from their doctor/nurse/pharmacist and from their family and or peers. It also includes physical factors such as the ease of access to the health care system, and their financial circumstances.  
  • Motivation describes how much they want to take their medicines and includes their beliefs about their illness and their treatment, their mood state, their confidence in managing their health, and the strength of their medication taking habit.  

All three factors are important for taking medication regularly and for any individual patient, their non-adherence could be due to any one or more of these factors.

CF: How common is this, ie what percentage of patients do not take medications as prescribed?

JW: The WHO’s figure of around 40-50% non-adherence is a fair overall estimate of the problem in people taking medicines for long-term conditions. The more recent OECD working paper in 2018 reports a very similar figure, and there are many studies with equivalent findings across a wide range of medical problems. Estimates of non-adherence can vary a bit from study to study because of differences in the ways in which adherence is assessed and defined.

CF: Do you think this issue is getting worse? How much of it can be blamed on the many horror story headlines in the media and misinformation online? 

JW: Possibly but levels of non-adherence have remained high since adherence research started around 50 or 60 years ago. One factor that does seem to have affected peoples’ willingness to adhere is the influence of social media and the large amount of information that is available on the internet (‘Dr Google’). For some patients, particularly those who have experienced poorer support from their doctors, they may well turn to media and web-based information, which may not always be accurate.

CF: Is another issue that people often forget to take them?

JW: Forgetting is one of many reasons (see above) and is also an issue for people who are less motivated or have not made a good daily plan for taking their medicines. Reminder aids and apps can help people for whom forgetting is their main problem (ie unintentional non-adherence) but reminders are not helpful for people who are not motivated or who have become non-adherent.

CF: What are the estimated costs to the NHS each year?

JW: I don’t have an up-to-date figure on the cost to the NHS but the 2018 OECD working paper on medication non-adherence concluded that it costs the EU approximately 125 billion euros per year.

CF: Are there solutions that have been proven to work that encourage or remind people to take their medicines? 

JW: Reminder aids and apps can help people for whom forgetting is their main problem and there are hundreds now available, but they have been shown to not be effective because they often don’t target the key reason(s) for any individual patient. There are some successful approaches, which assess individual reasons and then use a personalised, targeted interventions using a range of behaviour change methods.