Asking good clinical research questions and choosing the right study design

Clinicians and researchers seek answers to clinical research questions, primarily by accessing the results of clinical research studies. This paper moves the focus of research enquiry from getting answers to developing good clinical research questions. Using worked examples, the steps involved in refining questions drawn from various sources to create 'answerable' clinical research questions using the 'PICO' principle are described. Issues to consider in prioritising clinical research questions are also identified. Theoretical and practical considerations involved in choosing the right study design for a clinical research question are then discussed using the worked examples. These include: Categorisation of questions according to their central clinical issues; Use of preliminary literature searching to identify existing research and further refine questions; Identifying whether a quantitative or qualitative research paradigm is best suited to a research question; Hierarchies of evidence that rank study designs and how they vary according to central clinical issues; Other factors influencing study design selection. (C) 2010 Elsevier Ltd. All rights reserved.