Dear Statalist folks,
I'd like to ask advice on interpreting the output of -senspec-. I've
created the following simple simulation example which allows me to
compare the -senspec- output to a simple 2x2 table. The following code
shows that the absolute numbers from -senspec- agrees with each cell
of my 2x2 table, but the frequency values are different. Am I
misinterpreting or mis-applying -senspec-?
clear
set obs 1000
set seed 12358
gen test=1 + int(2*uniform())
replace test=0 if test==2
replace test=1 in 1/300
gen disease=0 in 1/500
replace disease=1 in 501/1000
tab test disease, row
gen method=1 + int(2*uniform())
bysort method: tab test disease, row
tab test disease if method==1, row
senspec disease test if method==1, se(sens) spe(spec) fpos(fpos)
ntneg(ntneg) fneg(fneg) ntpos(ntpos) nfpos(nfpos) nfneg(nfneg)
* cellA: ntneg sp cellB: nfneg fneg cellC: nfpos fpos cellD:
ntpos se
list test disease ntneg spec nfneg fneg nfpos fpos ntpos sens in 1/10
Thank you kindly.
Michael McCulloch
Pine Street Foundation
124 Pine Street
San Anselmo, CA 94960-2674
tel: 415-407-1357
fax: 206-338-2391
[email protected]
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