Is it appropriate to conduct an unpaired t-test with only summary means from both groups? For example, let's say you want to compare: a. Professor A's scores received on a evaluation by his ...
500 patients had an operation to remove stomach cancer. There exists a clinical guideline that suggests that a minimum of ten lymph nodes should be removed during the operation. I am therefore ...
All - I have a dataset originated from a practical setting, but it is not clear to me how to interpret it. Let me try to frame the setting and see if it makes sense: A manufacturer produces a type ...
How to describe the differences in skewed data with same median but statistically different distribution?
I am comparing length of stay after laparoscopic and open appendectomy in over 160000 patients. LOS is typically a skewed variable so I use the median and interquartile range and ranksum test to ...
I am using $\chi^2$ to analyze a set of data gathered over 4 time periods. The two variables are independent--each 'event' is categorized as 'good' or 'bad'. We want to prove that the intervention ...
I have a dataset of cases and age & sex matched controls (n=25). I need to do a statistical test to find the significantly different incidences of ICD-9 codes using a p-value or similar measure. ...