Interpretation of Data and Analysis of Surgical Trials

Summary: A well-conducted analysis starts at the planning phase of a study because the analysis cannot provide what the data collection process did not. It cannot be stressed enough the importance of formulating the clinical questions to answer, because they determine the statistical hypotheses to be tested. We discuss important steps to follow in the analysis of orthopaedic surgical trials. Trialists should remain critical of their own data and attempt to identify any factors that could bias their analysis and results. The statistical and clinical significance of the results should be assessed by presentation of effect estimates, confidence intervals, and exact P values.