Authors’ contributions
GN, MP, PVD, FM
PVD
FL, SSA, FM, and MP conceived, planned, and finalized the statistical analysis plan, with review by AA, ACL, CJM, PC, PVD, LHVdB, OH, GN, NV, and BD. AA is the chief investigator of the TUDCA-ALS study. MP is the senior statistician responsible. FL, SSA, FM, MC, and MP drafted the manuscript. AA, ACL, CJM, PC, PVD, LHVdB, OH, NV, and BD contributed to developing the research questions and study designs. FL and SSA contributed equally as co-first authors of the manuscript. FL, SSA, FM, MC, and MP read, amended, and approved the statistical analysis plan. All authors have read and approved the final manuscript.