John Uebersax

2006-08-04 07:43:18 UTC

Is there a standard way to estimate the confidence interval

for the difference between two non-independent proportions?

For example, let:

N = no. of patients

p1 = proportion of asymptomatic (vs. symptomatic) patients

pre-treatment

p2 = proportion of asymptomatic (vs. symptomatic) patients

post-treatment

How would one get the 95% CI for (p2 - p1)?

The McNemar test can be used to test whether (p2 - p1) differs

significantly from 0, but it does not supply a means of getting

a confidence interval.

The only literature I've located is a note by CC Hsieh in

Stat Med (1985):

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=3992071&query_hl=1&itool=pubmed_docsum

but so far I've been unable to see the article and don't know

what method it used.

Thanks in advance.

--

John Uebersax PhD

for the difference between two non-independent proportions?

For example, let:

N = no. of patients

p1 = proportion of asymptomatic (vs. symptomatic) patients

pre-treatment

p2 = proportion of asymptomatic (vs. symptomatic) patients

post-treatment

How would one get the 95% CI for (p2 - p1)?

The McNemar test can be used to test whether (p2 - p1) differs

significantly from 0, but it does not supply a means of getting

a confidence interval.

The only literature I've located is a note by CC Hsieh in

Stat Med (1985):

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=3992071&query_hl=1&itool=pubmed_docsum

but so far I've been unable to see the article and don't know

what method it used.

Thanks in advance.

--

John Uebersax PhD