```Date: Thu, 9 Feb 2006 21:14:00 -0700 Reply-To: Aric Zion Sender: "SPSSX(r) Discussion" From: Aric Zion Subject: Re: Odds ratio question Content-type: text/plain; charset=UTF-8 No, it means a 77% decrease in the odds (i.e. 1 - .23 = .77). If you think of it this way... that .866 means that a 1 unit change in x means that the odds gets multiplied by .866 (i.e. a 13.4% decrease), then compounding .866 ten times (i.e. .866^10) gives you .237 as an odds multiplier and 1 - .237 = .763. Aric -----Original Message----- From: SPSSX(r) Discussion on behalf of S Crawford Sent: Thu 2/9/2006 8:01 PM To: SPSSX-L@LISTSERV.UGA.EDU Cc: Subject: Odds ratio question Hi, everyone. I'm having problems with an odds ratio from a logistic regression. We are trying to predict a binary outcome (yes or no) based on one continuous variable (variable X). We get a significant overall regression. The B coefficient for this variable was -.144, and Exp(B) from the SPSS printout for variable X was .866. If we want to find out the change in odds for every 10 point increase in variable X, do we just take: .866 and raise it to the 10th power? That would be .23 rounding off - so does that mean a 23% decrease in odds of an abnormal outcome for every 10 point increase in variable X? Many thanks for the help. Susan _________________________________________________________________ Scan and help eliminate destructive viruses from your inbound and outbound e-mail and attachments. http://join.msn.com/?pgmarket=en-ca&page=byoa/prem&xAPID=1994&DI=1034&SU=http://hotmail.com/enca&HL=Market_MSNIS_Taglines Start enjoying all the benefits of MSNĀ® Premium right now and get the first two months FREE*. ```

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