clinical study

  1. S

    Sample size calculation when comparing two coefficients of variation

    Hi, I am a medical student, wanting to start a clinical study between two devices. Since I want to compare especially on precision and reproducibility, I am going to use the coefficient of variation. I already have the CV of one of the devices from another published article (14,6%) and have...
  2. O

    Clinical data sets and R scripts

    Good day. I am a Medical Doctor who was given an epidemiology task with COVID19 data. I need to do in R since its the only statistical program I know how to use. Does anyone knows where to find R scripts with their respective datasets in clinical research?
  3. S

    Sample size calculation

    Dear All, I am a vascular surgeon planning a research project. I need some advice regarding the sample size calculation. I am looking at the same group of patients pre and post-procedure looking for a change in the diameter of their main blood vessel at 2 different points. We have some data...
  4. C

    Study Design for assessing efficacy of New Clinical Sign

    Hi! I am looking for some guidance as to what statistical tests I would need to do to know the significance of a study. The situation is this: Disease in Question is Sinusitis Gold Standard for Diagnosis is CT, but is seldom done as not all cases require confirmation. Cost-effectiveness...
  5. S

    What type of regression I need to use?

    :confused: I am doing a medical research in which I am going to compare two methods of calculation of RBC life span. The older method is a difficult to do, but the results are certain. we want to validate new method based on older method. I want to find a statistical method to find any...
  6. D

    Tukey's HSD following repeated measures ANOVA using ezANOVA package

    Hi, I have a longitudinal balanced tendon injury study with two treatment groups of horses (n=6/group) with 5 measurements over 6 mos measured on multiple MRI sequences. I have multiple questions with how I want to analyze this information, but my current question is the most pressing: Below...
  7. N

    Paired longitudinal analysis

    Hello all, I need your advice. I am examining an new eye drops. In order to examine, an experiment was performed, in which a subject was enrolled, and one eye was randomized to get the drops, while the other was the control. Before giving the drops, some quantitative measure was taken on...
  8. A

    sample representativeness

    Is there a statistical test to show that a sample is representative of a population? or is just fufilling some criteria, ie sample source, data collection methods, screening criteria, etc. This is for a retrospective clinical study.