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Reporting of Adherence to Medication in Recent Randomized Controlled Trials of 6 Chronic Diseases: A Systematic Literature Review

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ABSTRACT

Background

International recommendations such as the CONSORT and International Conference on Harmonisation statements recognize patient adherence to prescribed treatment as an important aspect of a treatment’s evaluation, but this issue is little assessed.

Objectives

To evaluate how medication adherence was assessed and reported in recently published randomized controlled trials (RCTs).

Material and Methods

All publications of RCTs assessing pharmacological treatments in 6 major chronic diseases published in high-impact-factor journals in 2003 and 2004 were selected from the Medline database. Two investigators analyzed how medication adherence was assessed and reported.

Results

A total of 192 publications were analyzed: 71 in HIV infection, 48 diabetes mellitus, 24 rheumatoid arthritis, 23 asthma, 15 hypertension, 7 osteoporosis, and 4 about 2 of these diseases. The assessment of medication adherence was documented in 69 (35.9%) publications, by counting pill intake in half of these. Results of adherence were reported in 64 (33.3%) publications. Adherence was reported as a quantitative measure: Proportion of the treatment prescribed in 27 articles and as a qualitative measure (adherent patient, yes/no) in 41 (in 4 reports both techniques were used). When reported, the median intake of prescribed medication was 93%, and the median proportion of “nonadherent” patients was 6.2%.

Conclusions

There is important variability in the assessment and reporting of medication adherence in published RCTs of pharmacological treatments of selected chronic diseases, for a given disease and across diseases. Standardization is advisable to allow for comparisons among studies.

Section snippets

Materials and Methods

A systematic review of recent randomized controlled trials was performed. Publications of 6 major chronic diseases were included: HIV infection, asthma, rheumatoid arthritis, diabetes mellitus, hypertension, and osteoporosis. These diseases offer a range of different situations and potentially different methodological difficulties for assessing adherence, since some are asymptomatic and some require polymedication.

1. Selected Publications

Of the 637 publications identified, 192 were included in the analysis (Figure 1). The 445 publications excluded were mainly not randomized controlled trials (n = 91), not assessing a pharmacological therapeutic intervention (n = 131), or not about the selected diseases (n = 72).

The characteristics of the publications are given in Table 1. Publications described mainly trials in HIV infection (n = 71, 37%) and diabetes mellitus (n = 48, 25%). Thirty percent of the reports were published in general medical

Discussion

This study assessed the methodological variability in the field of medication adherence in reports of randomized controlled trials of self-administered pharmacological interventions for 6 chronic diseases published over 2 years in high-impact general medical and specialty journals. To our knowledge, this is the first description of methods used to assess adherence in a diverse sample of trials in different chronic conditions. It provides an unprecedented look into the assessment and reporting

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  • Cited by (0)

    This work was supported by grants from the Fonds d’Etude et de Recherche des Médecins de l’Assistance Publique des Hôpitaux de Paris (AP-HP) and from the Association de Recherche Clinique en Rhumatologie (ARCR, Pr Dougados, Cochin) Paris, France.

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