Particularly for chronic diseases, prescription drugs have become a significant, if not the main, component of treatment. But medications will only work if the prescription is the correct one in terms of drug, dose and dosing schedule for the patient and if the patient complies with the prescription. There are companies working on medication therapy management, which addresses the first issue, and it is a mandated component of Medicare Part D. There have also been multiple interventions developed to handle the compliance problem and an Annals of Internal Medicine article reviews the evidence on the effectiveness of these interventions, both by type of intervention and by disease. (Annals Article) The researchers ended up evaluating about 67 studies, which tested 18 different types of intervention. Adherence is a problem that begins with an estimated 20-30% of prescriptions never being filled and includes around 50% of medications for chronic diseases not being taken as prescribed. While estimates of the costs of medication adherence are wildly inflated, it is clearly a serious quality issue.
The researchers focused on whether interventions were effective for patients with a chronic disease and self-administered medications and whether improved adherence was associated with better health outcomes, which is what really matters. Adherence is complex, influenced by many factors related to disease, drug, patient and provider. Overall, the researchers concluded that a number of interventions showed the potential to raise adherence, but that there was less evidence that doing so would improve other outcomes. Just over half of the studies indicated that the intervention improved adherence and there were positive results across a number of chronic diseases and a few interventions were effective for several different diseases. Of the studies that improved adherence just over half also showed improvement in another health outcome, but about a third of the successful studies did not evaluate health outcomes. Successful interventions ranged from the simple and cheap, like text reminders, to the complex and expensive, like in-person counseling and on-going case management. Perhaps the strongest finding from a policy perspective is that simply lowering copays seems to have one of the strongest impacts on adherence.