PEARLS 119, October 2008, written by Brian R McAvoy

Clinical question
How effective are interventions for enhancing medicine adherence?

Bottom line
For short term treatments, several interventions improved adherence, including counselling, written information and personal telephone calls, but the effects were inconsistent from study to study, with only 4 of 10 interventions reporting benefits for both adherence and clinical outcomes. For long term treatments, no simple intervention, and only some complex ones, led to improvements in health outcomes.These included combinations of more convenient care (eg, provision at home), more thorough patient instructions, counselling, information, reminders, close follow-up, supervised self-monitoring, rewards for success, family therapy, couple-focused therapy, mailed communications, crisis intervention, manual telephone follow-up and other forms of additional supervision or attention.

Caveat
Short term treatments were limited to acute infections. Long term treatments included those for hypertension, hyperlipidaemia, asthma and/or chronic obstructive pulmonary disease, epilepsy, ischaemic heart disease, heart failure, rheumatoid arthritis, diabetes,TB, HIV infection, schizophrenia and depression. Even with the most effective methods for long term treatments, improvements in drug use or health were not large, considering the amount of effort and resources they can consume. Several studies showed that telling people about adverse effects of their medications did not affect their use of the medications.

Context
People who are prescribed self-administered medications typically take less than half the prescribed doses. Efforts to assist patients with adherence to medications might improve the benefits of prescribed medications, but might also increase their adverse effects.There are many reasons for non-adherence, including (but not restricted to) problems with the regimen (such as adverse effects), poor instructions, a poor provider-patient relationship, poor memory, and the patient's disagreement with the need for treatment or inability to pay for it.

Cochrane Systematic Review
Haynes RB et al. Interventions for enhancing medication adherence. Cochrane Reviews 2008, Issue 2. Article No. CD000011. DOI: 10.1002/14651858.CD000011.pub3. This review contains 9 trials of short term treatments and 69 trials of long term treatments, involving a total of 12,633 participants.