search for: pmc1121605

...ly 2 time points (baseline and a follow-up) previously. I appreciate many useful comments from some members, especially Dennis Murphy and Marc Schwartz who refered the following paper addressing specifically this type of study with only 2 time points: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1121605/ Basically, with only 2 time points (baseline and one follow-up), ANCOVA with follow-up as dependent variable and baseline as covariate should be used: follow-up = a + b*baseline + treatment Now I have a regular longitudinal study with 6 time points, 7 treatments (vehicle, A, B, C, D, F, G), m...

Hello, I am looking for a sample size function for samples sizes, to test proportions that are not binomial proportions. The proportions represent a ratio of (final measure) / (baseline measure) on the same experimental unit. Searches using RSeek and such bring multiple hits for binomial proportions, but that doesn't seem to fit my situation. Perhaps there's some standard terminology

...d the following two > papers: > > > Statistics notes: analysing controlled trials with baseline > and follow up measurements. > Vickers AJ, Altman DG. > BMJ 2001;323:1123?4. > http://www.bmj.com/cgi/content/full/323/7321/1123 > http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1121605/pdf/1123.pdf > > > The use of percentage change from baseline as an outcome in > a controlled trial is statistically inefficient: a > simulation study. > Vickers AJ. > BMC Med Res Methodol 2001;1:6. > http://www.biomedcentral.com/1471-2288/1/6 > http://www.biomedcentr...