Working as a bio-statistician across early to late phase oncology clinical trials I come across some contexts where conventional software does not provide the necessary calculations. The calculations themselves can be worked out in a few hours to a day. However there is a need to dig out the appropriate reference, maybe pay for it, read and figure out the results and write code to calculate and check the results – all of which could take a little time and effort.
The pages in this section will have such calculators. I currently have calculators on early phase single sample clinical trials with a survival endpoint, on the Cochran-Armitage trend test, on conditional power calculations, on the sample size for logistic regression , on the influence of large strata or sites in clinical trials, and on the sample size for matched case-control and cohort studies.