Introduction. Nonadherence to immunosuppressive therapy is recognized as a key prognostic indicator for poor posttransplantation long-term outcomes. Several methods aiming to measure medication nonadherence have been suggested in the literature. Although combining measurement methods is regarded as the gold standard for measuring nonadherence, self-report is generally considered a central component of adherence assessment. However, no systematic review currently exists to determine which instrument(s) are most appropriate for use in transplant populations.
Methodology. The transplant360 Task Force first performed a survey of the self-report adherence instruments currently used in European centers. Next, a systematic literature review of self-report instruments assessing medication adherence in chronically ill patients was conducted. Self-report instruments were evaluated to assess those which were: (a) short and easy to score; (b) assessed both the taking and timing of medication intake; and (c) had established reliability and validity.
Results. Fourteen instruments were identified from our survey of European centers, of which the Basel Assessment of Adherence Scale for Immunosuppressives met the aforementioned criteria. The systematic review found 20 self-report instruments, of which only two qualified for use in transplantation, that is, the Brief Antiretroviral Adherence Index and the Medication Adherence Self-Report Inventory.
Discussion. The three selected self-report scales may assist transplant professionals in detecting nonadherence. However, these scales were only validated in patients with HIV. Although HIV shares similar characteristics with transplantation, including the importance of taking and timing of medication, further validation in transplant populations is required.
1Department of Public Health, Katholieke Universiteit Leuven, Centre for Health Services and Nursing Research and Heart Transplantation Programme, Leuven, Belgium.
2Institute of Nursing Science, University of Basel, Basel, Switzerland.
3Department of Gastroenterology and Hepatology, University Hospital Groningen, Groningen, The Netherlands.
4Transplant Institute, Sahlgrenska University Hospital, Gothenburg, Sweden.
5Department of Transplantation, The Royal London Hospital, Whitechapel, London, United Kingdom.
6Integrated Research and Treatment Centre, Hannover Medical School, Hannover, Germany.
7Members of the transplant360 Task Force (see Appendix to this article).
Medical writing support in the preparation of this manuscript was provided by Choice Pharma and funded by Astellas Pharma Europe Ltd.
All authors receive remuneration from Astellas Pharma Europe Ltd. for their attendance at Task Force meetings. There are no further conflicts of interest to declare.
8Address correspondence to: Fabienne Dobbels, Ph.D., Katholieke Universiteit Leuven, Centre for Health Services and Nursing Research and Heart Transplantation Programme, Kapucijnenvoer 35/4, B-3000 Leuven, Belgium.
F.D. participated in review design, performing the review, writing the article, and analysis of findings; L.B. participated in review design and reviewing the article; S.D.G. participated in review design and reviewing the article; G.D. participated in review design and reviewing the article; A.L. participated in review design and reviewing the article; C.W. participated in review design and reviewing the article; C.K. participated in review design, performing the review, and reviewing the article; and the members of the transplant360 Task Force participated in reviewing the article.
Received 18 January 2010. Revision requested 9 February 2010.
Accepted 15 April 2010.