Footnotes

• Contributors BCC was involved in study design and statistical analysis, and wrote the manuscript. KAK helped with study design, statistical interpretation, and contributed to the manuscript. MB helped with the statistical analysis plan and interpretation, and contributed to the manuscript. RL performed the screening and medical chart abstraction and participated in the study design. AR assisted in the statistical analysis. PL contributed to the manuscript. LBM, ELF, and LDL were involved in the planning of the project, interpretation of the statistical analysis and contributed to the manuscript. PL, Frank Bonikowski and J Felipe Santos helped coordinate this project at their respective sites.

• Funding BCC was supported by a NIH T32 grant and an American Diabetes Association (ADA) Junior Faculty Award and is currently supported by NIH K23 NS079417. BCC and ELF are supported by the Katherine Rayner Program and the Taubman Medical Institute. KAK is supported by NIH/NCRR K23 RR024009 and AHRQ R18 HS017690. LBM is supported by the following NIH funding (significant): R01NS38916, R01NS062675, U01NS056975, U01NS062835, R18HS017690, R01NS073595, and R01HL098065. He also receives significant research support from St. Jude Medical. ELF is supported by NIH R24 DK082841-01 and NIH UO1 DK076160. LDL is supported by NIH/NINDS R01 NS38916, NIH/NINDS R01 NS062675, NIH/NHLBI R01 HL098065, and NIH/NINDS R01 NS070941.

• Competing interests KAK received speaker honoraria from the American Academy of Neurology and Munson Medical Center, and served as a consultant for the American Academy of Neurology, and The Weinberg Group. KAK and LBM also provide expert medical legal work (modest) that does not involve industry.

• Ethics approval University of Michigan IRB.

• Provenance and peer review Not commissioned; externally peer reviewed.