Medication adherence: understanding the issues and finding solutions.

Medication is the most frequent treatment intervention, and its success depends on patients taking their medicines in line with their prescribed regimen to yield the full benefit of the treatment. Adherence is especially difficult to ensure in those with multimorbidity, who take multiple medications to manage their conditions. Non-adherence is costly for the health service, both through wastage and increased ill health. Non-adherence may be intentional or non-intentional, and many factors affect an individual's compliance with a medication regimen. There are a variety of aids that may be helpful; however, the interaction with a health professional is very important, both for understanding the reason for non-adherence and for promoting adherence.