A randomised controlled trial of implementation of a guideline-based clinical pathway of care to improve health outcomes following whiplash injury (Whiplash ImPaCT): Statistical analysis plan

Background: Statistical analysis plans describe the processes of data handling and analysis in clinical trials; by doing so they increase the transparency of the analysis and reporting of studies. This paper reports the planned statistical analysis plan for the Whiplash ImPaCT study. For individuals with whiplash injury, Whiplash ImPaCT aims to assess the effectiveness of a guidelines-based clinical pathway of care compared with usual care. Methods: We report the planned procedures, methods, and reporting for the primary and secondary analyses of the Whiplash ImPaCT study. The primary outcomes are Global Recovery and Neck Disability Index at 3 months post-randomisation. Outcomes will be analysed according to the intention to treat principle using linear mixed models. A cost-utility analysis will be conducted to compute the incremental cost-effectiveness of the intervention to usual care. We describe data handling, our analytical approach, assumptions about missing data, and our planned methods of reporting. Discussion: This paper will provide a detailed description of the planned analyses for the Whiplash ImPaCT trial.