Any time you learn anything new it can be intimidating. That is true of programming as well as anything else. It may be even more true of using statistical software because you combine the uneasiness many people have about learning statistics with learning a new language.
To a statistician, this error message makes perfect sense:
ERROR: Variable BP_Status in list does not match type prescribed for this list.
but to someone new to both statistics and SAS it may be clear as mud.
Here is your problem.
The procedure you are using, PROC UNIVARIATE , PROC MEANS is designed ONLY for numeric variables. You have tried to use it for a categorical variable.
This error means you’ve used a categorical variable in a list where only numeric variables are expected. For example, bp_status is “High”, “Normal” and “Optimal”
You cannot find the mean or standard deviation of words, so your procedure has an error.
So … what do you do if you need descriptive statistics?
Go back to your PROC UNIVARIATE or PROC MEANS and delete the offending variables. Re-run it with only numeric variables.
For your categorical variables, use a PROC FREQ for a frequency distribution and/ or PROC GCHART.