The Importance of Study Design in the Spine Literature

Careful study design is essential to carry out high quality research that yields valid results. Planning an effective study involves defining the target population, specifying an intervention, selecting appropriate outcome measures, and choosing the appropriate design. Randomized controlled trials, observational cohort studies, and case-control studies all have advantages and disadvantages. When planning or evaluating a study, threats to its validity, including chance, bias, and confounding must be considered. Although the randomized controlled trial may be considered the most valid design, well-designed observational studies often yield similar results. This article reviews these concepts, using examples from the spine literature.