Hi, this is probably a very basic question but I am trying to create ROC curves for strength scores and disease presence (binary) - higher strength scores would be associated with lower disease risk. I am also using probability weighted survey data.

Code:
svy: logistic disease1 strength
predict phat1
somersd  disease1 phat1 [pweight=pwt], tr(c)
I have had to invert my disease variable ('disease' -> 'disease1') so that the ROC curve would be the right way up i.e. I changed the scores so that 0 = disease, 1 = no disease. By right way up, I mean AUC >0.5 (it was around 0.3 with the original 'disease' variable).

My problem is that I now want to compare this to another ROC curve where I have used the original non-inverted disease variable (i.e. 'disease' where 0 = no disease, 1 = disease). However, as I have used 2 different outcome variables (i.e. one where 0 = disease and one where 0 = no disease) this comparison doesn't work.

Code:
roccomp disease-variable??? phat1 phat2, graph summary
Is there a way to tell the logistic regression that low strength scores are 'bad' rather than the way I have inverted the disease variable? Or is there a way to compare the ROC curves with these 2 disease variables.

I am using stata v16.0.

I would be really grateful if anyone could give me some advice about how best to approach this. Thank you.