Footnotes

• Contributors ADdJ, RPAvE and LHvdB designed the study. ADdJ and RPAvE analysed the data and drafted the manuscript. RPAvE and LHvdB critically reviewed the manuscript.

• Funding This study was supported by the Netherlands ALS Foundation (Project TRICALS-Reactive 2018-66).

• Competing interests ADdJ and RPAvE report no disclosures. LHvdB reports grants from Netherlands ALS Foundation, the Netherlands Organization for Health Research and Development (Vici scheme), the Netherlands Organization for Health Research and Development (SOPHIA, STRENGTH, ALS-CarE project), funded through the EU Joint Programme – Neurodegenerative Disease Research, JPND), served on the Scientific Advisory Board of Biogen, Cytokinetics, Prinses Beatrix SpierFonds and the Latran Foundation.

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

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