The blog article by Rick Wicklin https://blogs.sas.com/content/iml/2015/04/20/waterfall-plot.html explains what waterfall plots are. My question is, what is the appropriate statistical test which could be applied to assess differences between placebo and treated group by comparing corresponding watterplots (considering each set having data for at least 50 subjects)? ChatGPT sugests: 'To compare waterfall plots, one approach is to use a statistical test that compares the distribution of the changes in tumor size or marker levels between two treatment groups. One such test is the Wilcoxon rank-sum test, also known as the Mann-Whitney U test. This non-parametric test compares the ranks of the changes in tumor size or marker levels between the two groups, and can be used to determine if there is a statistically significant difference in tumor response between the two treatments.' Is it all one can do or is there a more tailored test taking into account the characteristic distribution of the data, i.e. bound from below and above tumor growth/shrinkage (there is at maximum 100% reduction of tumour and it is only open in theory on the other side but of course limited physically from unrestricted growth)?
... View more