@HealthMed A surprisingly common problem: WHO estimates published in 2003 and more recent studies suggest that in the developed world around 50% of patients with chronic medical disorders such as diabetes and asthma do not take their medicines regularly. Indeed, for example, for high blood pressure, around half the patients on drug treatment have stopped taking their tablets within the first year of starting treatment. Despite this evidence that many patients are not benefiting from prescribed medicines, these data may even be underestimates of prevalence of low adherence to medicines, as clinical studies are typically conducted in patients willing to participate, who have less co-morbidity and have fewer prescription medicines than is usual in the general population of patients.
There are multiple potential contributory factors, including costs of paying for medicines, lack of insight into medical conditions or awareness of ways in which medicines may help, perceptions that medicines are not working, and concerns about potential or actual adverse effects of medicines.
Personalising medicines using genetic and other companion diagnostics may help to improve adherence by avoiding drugs more likely to cause adverse effects.
Identifying and improving poor adherence is important to maximise disease control, improve quality of life, and to avoid unnecessary investigation, avoidable treatment escalation and avoidable adverse effects if treatments not normally taken are taken variably by a patient or are dispensed e.g. during acute medical admission.
Poor adherence can be recognized in a number of ways, including direct discussion with the patient, tablet counts, checking timeliness of prescription renewal, and both clinical and laboratory clues from expected biological effects of the medicines.
More studies are needed to identify ways to be more effective in helping patients to be more adherent to their medicines. Meantime the UK'S NICE recommends regular informed discussion with patients to improve adherence to their medicines.