Aim: This paper is a report of an analysis of the concept of adherence.
Background: The transition in terminology from compliance to adherence, and more recently to concordance, requires re-clarification of 'adherence' as a concept in nursing practice. Differences exist in the use of the term adherence and how or if it differs from compliance or concordance.
Data sources: Using the Medical Subject Headings terms adherence, non-adherence and treatment refusal, the Cumulative Index to Nursing and Allied Health Literature, Medline, PsychINFO and Cochrane library databases were searched for publications between 1970 and 2007. Method. The evolutionary analytic method was used to identify and explore transitions in the concept of adherence over time and across healthcare disciplines. A representative sample of papers was identified from the disciplines of nursing, medicine, psychology and pharmacy.
Results: We identified 114 papers: 27 from nursing, 39 from psychology, 33 from general medicine and 15 from pharmacology sources. The final sample included eight from pharmacy and 15 from mental health, medicine and nursing. We found no distinct differentiation between adherence and compliance. The surrogate terms serving as manifestations of adherence are concordance, agreement, cooperation and partnership. The most common definition found was as follows: 'Adherence can be defined as the extent to which patients follow the instructions they are given for prescribed treatments'. No definition of adherence exists that reflects a patient-centred approach, the dynamic nature of adherence behaviour and the power imbalance implied by these terms.
Conclusion: This concept analysis of adherence is a preliminary step towards broadening nurses' appreciation of the complexity of patient adherence behaviour.