Search results

  1. Q

    Comparing improvement between two groups. (pre vs post)

    I have two groups. Each consists of an equal number of subjects. They are given a test. Then they are 'trained' differently. Then the test is repeated. I want to statistically compare the improvement between groups. My data is not normal (the scores on the tests). I initially used a rank...
  2. Q

    Comparing 95% confidence intervals between groups: Krippendorff’s alpha

    I am performing an interrater reliability analysis. My analysis has several nominal variables that are being graded and I’ve used Krippendorff’s alpha to generate my interrater reliability statistic. I want to compare reliability between two groups (trained differently). I have 95% confidence...
  3. Q

    Interrater reliability for many raters (20) and ordinal/nominal variables

    I am trying to assess interrater reliability for different medical training groups. Each group consists of 20 raters/doctors. They then assess 5 cases. Each case involves a series of 30 questions. The questions are either ordinal or nominal. The ordinal ones have 3 or 4 rankings. The nominal...
  4. Q

    Chi Square: Columns are repeated measures of ordinal dependent variable?

    I have 300 people. They are placed into one of two groups (Group_Variable: A or B). Then four measurements are taken (V1, V2, V3, V4) and these are on an ordinal scale (1-3). [The four measurements are on different parts of the body but should theoretically have the same value - for example...
  5. Q

    95% CI for rare incidence rate increasing in time.

    I'm very confused by the above equations. Definitely not a stat expert, and I don't know what a, b, time, or timebar mean. I tried to search and I'm not getting very far. With regards to the comment above from hlsmith, yes the point of the graph is to draw conclusions regarding an increasing...
  6. Q

    95% CI for rare incidence rate increasing in time.

    I just used unadjusted Poisson distribution for a CI.
  7. Q

    95% CI for rare incidence rate increasing in time.

    Can I simply calculate the Poisson distribution interval for each year as I've done (thereby assuming a 'relatively' constant rate over the course of a single year). The fact that the rate increases over the entire study period doesn't necessarily violate the 'constant rate' assumption of a...
  8. Q

    95% CI for rare incidence rate increasing in time.

    I have a plot of 10 incidence rates across time (see picture). I want to calculate the 95% confidence interval for each rate. It would be easiest to just do a normal distribution calculation, but I'm concerned this is not applicable here. For one, they are rare events. I thought to do a poisson...
  9. Q

    P values from 95% CI using poisson distribution

    Hi, Hope I'm in the best place for an answer :) I have a study across 10 years. I have an incidence rate that was calculated for each year along with the 95% confidence interval using a Poisson distribution. My question is how do a get p-values for pairwise comparisons? I understand I can say...