Hi, I'm new on this forum, thanks for reading my post!
I'm trying to figure out if I've used the best method for determining a relationship between variables (calculations done using Excel).
I have a cohort of 38 trauma patients of different ages.
I have measured their aortic diameter on arrival in Emergency Department, and aortic diameter just prior to their discharge from hospital (ie when they are well) using CT scans.
I have also dichotomised whether they were haemodynamically unstable (1) or stable (0).
I have used Pearson correlation coefficient to look at correlation between age and aortic diameter change (hypothesising that younger people have a greater increase in aortic diameter)
I have used point-biserial correlation to look at correlation between haemodynamic status and aortic diameter change (hypothesising that haemodynamically unstable patients also have a greater increase in aortic diameter)
I have also created a scatter plot with a trend line in Excel.
Are these calculations valid and appropriate to my data? Should I be using something else?
Thanks so much!