Abstract
Study design is critical to ensure that research questions are answered in an appropriate and rational manner for all aspects of health, but particularly in emergency care. Appropriate study design selection is one of the most critical decisions to make at the earliest stage of a research project; once this is clear, much of the methodology and sample size estimations should be straightforward. Selection of an appropriate study design is fundamental to good research and deserves careful consideration at the outset of any research project. The classic gold standard for study design is the double-blind randomised clinical trial, but it is often not possible to achieve this ideal in the busy clinical emergency environment or with the resources available. Descriptive studies are common in emergency care; they include retrospective clinical records reviews, prospective cohort studies and case-control studies. Case reports and surveys can be a useful introduction to research for novice researchers. When sufficient empirical evidence on a topic exists, results of similar studies can be combined in systematic reviews and/or meta-analyses to pool the results from multiple studies to determine stronger evidence for or against an intervention or treatment, but these techniques require specialist expertise and statistical skills.