Article Text
PostScript
Letter
Compositional data analysis
Statistics from Altmetric.com
Footnotes
Contributors LB is responsible for the statistical part. PS wrote the letter and is the corresponding author.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; internally peer reviewed.