- All > Medicine Information and Evidence for Policy > Medicines Policy
- All > Medicine Access and Rational Use > Rational Use
- Keywords > adherence and compliance
- Keywords > adherence to prescribed medication regimens
- Keywords > adherence to treatment
- Keywords > chronic disease
- Keywords > long term therapies
- Keywords > patient medication compliance
- Keywords > patients - compliance behavior
- Keywords > pharmacy - based adherence programmes
- Keywords > use of medicines
- Keywords > uso de medicamentos
(2003; 4 pages) [French] [Spanish]
Adherence to long-term therapies for chronic diseases in developed countries averages only 50%. In developing countries the rate is even lower, probably reflecting inequalities of access to appropriate health care facilities, supervised by qualified health care professionals.
HIV/AIDS, tuberculosis and non-communicable diseases including mental health disorders, represented 54% of all illnesses world-wide in 2001 and are estimated to exceed 65% in the year 2020. Thus the burden of illness is moving quite strongly towards chronic diseases. There is evidence that many patients with chronic illnesses have difficulty in adhering to their recommended treatment regimens. Adherence problems are observed whenever patient self-treatment is required, including for prevention. Poor adherence results in poor health outcomes and increased health care costs. It has been estimated that 40% of cases of acute myocardial infarction or stroke are attributable to hypertension and yet studies have shown that despite the availability of effective treatments, less than 25% of patients treated for hypertension achieve optimal blood pressure.
Thus the cost to patients of non-adherence is avoidable illness, in some cases premature death. The cost to health care systems of non-adherence is represented by medicines paid for but not taken plus avoidable additional treatment. In the case of communicable diseases, non adherence may lead to the development of resistance to medicines, making successful treatment much more difficult. Many published papers testify to changes in costs following changes in adherence rates. Some studies show that initial investments in interventions to improve adherence are fully recovered in a few years and recurrent costs fully covered by savings.
There are, therefore, many reasons for seeking to improve adherence. The benefits include better health outcomes and improved quality of life and improved safety for the patient, as well as cost savings for all stakeholders. Indeed it has been stated that increasing the effectiveness of adherence interventions may have a far greater impact on the health of the population than any improvement in specific medical treatment.