Dear all:

You just subtract an odds ratio to get the odds ratio for the opposite condition (eg. reduced 
risk from breastfeeding vs. increased risk of not breastfeeding).  It is a logarithm.  Karleen 
Gibble was the first one who noticed this mistake on the part of some very astute public 
health professionals.  She and I actually both made a mistake because we treated it as a 
simple multiplicatiion problem.  Much later I talked to an epidemiologist who reminded me 
what I had once been taught and had forgotten about the logarithm formula.  If push came 
to shove, I could dig up the formula from my old books.  

Best, Susan

             ***********************************************

Archives: http://community.lsoft.com/archives/LACTNET.html
Mail all commands to [log in to unmask]
To temporarily stop your subscription: set lactnet nomail
To start it again: set lactnet mail (or [log in to unmask])
To unsubscribe: unsubscribe lactnet or ([log in to unmask])
To reach list owners: [log in to unmask]