Methods Retrospective, cross-sectional and matched case-control study designs have
commonly been used to analyze outcomes such as mortality, length of stay, and
complications. The NTDB's large size facilitates the study of rare injuries, procedures, and
outcomes. A brief description of NTDB should be included to inform the reader about the
characteristics of this data set. The rationale for using NTDB vs other available data should
also be provided. Sample inclusion/exclusion criteria should be explicitly stated. We …