Elsevier

The Lancet

Volume 348, Issue 9024, 10 August 1996, Pages 383-386
The Lancet

Series
Systematic review of randomised trials of interventions to assist patients to follow prescriptions for medications

https://doi.org/10.1016/S0140-6736(96)01073-2Get rights and content

Summary

Background

Low adherence of patients to prescribed, self-administered medical interventions is ubiquitous. Low adherence limits the benefits of current medical care. Efforts to assist patients to follow treatments might improve the efficiency of care and substantially enhance benefits. Our objective was to summarise the results of randomised controlled trials (RCTs) of interventions to help patients follow prescriptions for medications.

Methods

A previous systematic review was updated through computerised searches in Medline, International Pharmaceutical Abstracts, Psychinfo, and HSTAR online databases; bibliographies in articles on patient adherence; articles in the reviewers' personal collections; and contact with authors. Articles were judged of interest if they reported original data concerning an unconfounded RCT of an intervention to improve adherence with prescribed medications, with one or more measure of medication adherence, one or more measure of treatment outcome, at least 80% follow-up of each group studied, and, for long-term treatments, at least 6 months of follow-up for studies with positive initial findings. Information on study design features, interventions and controls, and findings were extracted by one reviewer (RK) and checked by the other two reviewers.

Findings

1553 relevant citations and abstracts were screened, 252 full text articles were reviewed in detail, and 13 RCTs met all criteria. The studies were too disparate in clinical problems, adherence interventions, measures and reporting of adherence, and the clinical outcomes studied to warrant meta-analysis. Seven of 15 interventions were associated with improvements in adherence and six interventions led to improvements in treatment outcomes. For short-term treatments, one study showed an effect on adherence and outcome of counselling and written information. The interventions that were effective for long-term care were complex, including various combinations of more convenient care, information, counselling, reminders, self-monitoring, reinforcement, family therapy, and other forms of additional supervision or attention. Even the most effective interventions did not lead to substantial improvements in adherence.

Interpretation

Although adherence and treatment outcomes can be improved by certain—usually complex— interventions, full benefits of medications cannot be realised at currently achievable levels of adherence. It is time that additional efforts be directed towards developing and testing innovative approaches to assist patients to follow treatment prescriptions.

Introduction

Non-adherence with prescribed treatments is very common. Typical adherence rates for prescribed medications are about 50% with a range from 0% to over 100%.1 To the extent that treatment response is related to dose, non-adherence reduces treatment benefits2 and can bias assessment of the efficacy of treatments.3 With increasing numbers of efficacious self-administered treatments, the need is apparent for better understanding and management of non-adherence.

In previous reviews, we have examned the accuracy of clinical measures of non-adherence,4 interventions to improve attendance at appointments for medical services,5 and interventions to enhance medication adherence.6 In the last review some of the included trials were confounded. For example, in one study,7 interventions to increase medication adherence among patients with hypertension were inextricably intertwined with strategies to increase screening for this condition. Our aim in the current review is to summarise all unconfounded randomised control trials (RCTs) of interventions to increase adherence with prescribed medications. Ethical standards for adherence research dictate that attempts to increase adherence must be judged by their clinical benefits, not simply their effects on adherence rates.8 Accordingly, we included only RCTs in which both adherence and treatment effects were measured.

Section snippets

Methods

Unconfounded RCTs of interventions intended to improve adherence with prescribed medications were sought and selected if they reported original data concerning medication adherence, with at least 80% follow-up of participants, and with one or more measures of both medication adherence and treatment outcome. For long-term regimens, studies with initially positive findings were required to have at least 6 months' follow-up from the time of patient entry; negative trials with shorter periods of

Results

Searches of all sources retrieved 1553 citations (including 73 review articles), 252 of which were judged to merit scrutiny of the full article. 13 of the latter articles met all review criteria.9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 Key features of these 13 trials are summarised in the table.* A narrow range of disorders was studied, with five studies in hypertension, three in schizophrenia, one in asthma, one in epilepsy, and only two for short-term conditions (infections in both

Discussion

Most people have difficulty following self-administered medical treatments. The benefits from such treatments are diminished according to the degree of non-adherence and the efficacy of the treatments.1 With the astonishing advances in medical therapeutics during the past two decades, one would think that studies on the nature of non-adherence and on the effectiveness of strategies to help patients overcome it would flourish. On the contrary, little has been published. Compared with the many

References (26)

  • MJ Bass et al.

    Do family physicians need medical assistants to detect and manage hypertension?

    Can Med Assoc J

    (1986)
  • Management of patient compliance in the treatment of hypertension

    Hypertension

    (1982)
  • AL Johnson et al.

    Self recording of blood pressure in the management of hypertension

    Can Med Assoc J

    (1978)
  • Cited by (542)

    • Lipid-Lowering Therapy in PURE Poland Cohort Study

      2024, Journal of Clinical Medicine
    View all citing articles on Scopus

    A list of randomised trials of adherence interventions that failed on one or more criteria can be obtained from the authors

    View full text