help for diagt, diagti in stata use the definitions of specificity and sensitivity using a 2x2 table :
Sensitivity (sens.) as the proportion of diseased patients correctly identified = a/(a+b). Specificity (spec.) is the proportion of healthy patients correctly identified = d/(c+d).
so, when using the episensi command, I am not understanding how we now are supposed to come up with separate sensitivities and separate specificities needed for the command:
dseca(pdf_option) define the sensitivity among the cases
dspca(pdf_option) define the specificity among the cases
dsenc(pdf_option) define the sensitivity among the noncases
dspnc(pdf_option) define the specificity among the noncases
can someone help me? perhaps I'm missing a really basic point here.