ABSTRACT
This chapter discusses the methodological issues behind the choice of research design in this field. The concepts of evidence-based practice (EBP) for all health care professionals and evidence-based policy in the NHS give more weight to patients' values and NHS costs, and focus upon broader issues of resource allocation rather than individual clinical practice. As the number of trials increases across the world, the concern about practical relevance becomes critical in health services research. The chapter explores the distinction between explanatory trials and pragmatic trials. As UK Alcohol Treatment Trial (UKATT) aimed to generate evidence to guide commissioning decisions for services in the UK, there was a prima facie case for a pragmatic trial. The implementation of evidence-based practice poses a challenge in all fields of health care, not least because this includes four distinct tasks. Motivational interviewing poses particular problems because of variations in practice and the wide range of therapist variables that influence outcome.
