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Interventions for enhancing medication adherence

  • Review
  • Intervention


  • RB Haynes,

  • X Yao,

  • A Degani,

  • S Kripalani,

  • A Garg,

  • HP McDonald

Prof R. Brian Haynes, Chair, Clinical Epidemiology & Biostatistics and Medicine, McMaster University, Faculty of Health Sciences, 1200 Main Street West, Rm. 2C10B, Hamilton, Ontario, L8N 3Z5, CANADA.



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 also might increase their adverse effects.


To update a review summarizing the results of randomized controlled trials (RCTs) of interventions to help patients follow prescriptions for medications for medical problems, including mental disorders but not addictions.

Search strategy

Computerized searches were updated to September 2004 without language restriction in MEDLINE, EMBASE, CINAHL, The Cochrane Library, International Pharmaceutical Abstracts (IPA), PsycINFO and SOCIOFILE. We also reviewed bibliographies in articles on patient adherence and articles in our personal collections, and contacted authors of original and review articles on the topic.

Selection criteria

Articles were selected if they reported an unconfounded RCT of an intervention to improve adherence with prescribed medications, measuring both medication adherence and treatment outcome, with at least 80% follow-up of each group studied and, for long-term treatments, at least six months follow-up for studies with positive initial findings.

Data collection and analysis

Study design features, interventions and controls, and results were extracted by one reviewer and confirmed by at least one other reviewer. We extracted adherence rates and their measures of variance for all methods of measuring adherence in each study, and all outcome rates and their measures of variance for each study group, as well as levels of statistical significance for differences between study groups, consulting authors and verifying or correcting analyses as needed.

Main results

For short-term treatments, four of nine interventions reported in eight RCTs showed an effect on both adherence and at least one clinical outcome, while one intervention reported in one RCT significantly improved patient compliance, but did not enhance the clinical outcome. For long-term treatments, 26 of 58 interventions reported in 49 RCTs were associated with improvements in adherence, but only 18 interventions led to improvement in at least one treatment outcome. Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes. Six studies showed that telling patients about adverse effects of treatment did not affect their adherence.

Authors' conclusions

Improving short-term adherence is relatively successful with a variety of simple interventions. Current methods of improving adherence for chronic health problems are mostly complex and not very effective, so that the full benefits of treatment cannot be realized. High priority should be given to fundamental and applied research concerning innovations to assist patients to follow medication prescriptions for long-term medical disorders.

Plain language summary

Plain language summary

Many people do not take their medication as prescribed. Our review considered trials of ways to help people follow prescriptions. For short-term drug treatments, counseling, written information and personal phone calls helped. For long-term treatments, no simple intervention, and only some complex ones, led to improvements in health outcomes. They included combinations of more convenient care, information, counseling, reminders, self-monitoring, reinforcement, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and other forms of additional supervision or attention. Even with the most effective methods for long-term treatments, improvements in drug use or health were not large. Fortunately, several studies showed that telling people about adverse effects of their medications did not affect their use of the medications.