I am in the midst of finalizing my Pearson correlation matrixes for my study which is looking at pain, physical function, mobility, HRQOL and range of motion outcomes and activity levels (leisure-type activity times in minutes over a week). I am using all self-reported data, and for the above mentioned variables, a VAS to gather continuous data. I was wondering if for my pain variable, which was inputted on a 5-point scale as: 0= no pain, 1= mild, 2= moderate, 3= severe, 4= excruciating, do I change it to match all other variables (e.g. physical function) which are scaled as 0= very poor, 1= poor, 2= good, 3= very good, 4= excellent?
So pain levels would now be scaled as 0= excruciating, 1= severe, 2= moderate, 3= mild and 4= no pain?