What is a psychological intervention? A metareview and practical proposal

Objective: What do we mean by a 'psychological intervention' in the context of cancer care? It is critical to know what treatments are included under this term, if data from diverse treatment trials are to be summarized in order to inform clinical practice. We, therefore, aimed to determine how the term 'psychological intervention' has been defined and used to group and compare interventions in reviews of cancer care. Methods: We conducted a review of existing reviews (a metareview). These included systematic and narrative reviews and meta-analyses of interventions that were described as 'psychological', with the aim of determining: (a) the definitions for 'psychological interventions' that were used and (b) the treatments that were included within this category. Results: We identified 66 relevant reviews. Surprisingly, we were unable to find any explicit definition of the term 'psychological intervention' in these reviews. The reviews included 79 different treatments with little consistency between reviews in which treatments were included. Conclusions: There is confusion about what 'psychological intervention' means in the cancer review literature. A clearer definition is essential to summarize research findings. We propose that rather than simply grouping interventions as 'psychological', it would be more useful if reviews focussed on specified domains of the interventions, namely content, proposed mechanism, target outcome, and methods of delivery. This would enable greater specificity in the review question, more meaningful comparisons, and would hopefully provide clearer answers for the readers of the reviews. A checklist for the summarizing of reports of interventions for review is provided. Copyright (C) 2010 John Wiley & Sons, Ltd.