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hello,
i'm doing a 1:1 matched case control study, gettin confused on how to go about with data analysis, particularly with regards to risk factors. some of the risk factors are binary (yes/no), some have multiple categories (eg; age <20yrs, 20 - 29 yrs, 30 - 39 yrs). how do i calculate the odds ratios for each category?? am confused |
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Administrator
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With 1:1 matching, you can perform conditional logistic regression via NOMREG. See David Garson's notes on it here: http://faculty.chass.ncsu.edu/garson/PA765/logistic.htm#matchedconditional
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Bruce Weaver bweaver@lakeheadu.ca http://sites.google.com/a/lakeheadu.ca/bweaver/ "When all else fails, RTFM." PLEASE NOTE THE FOLLOWING: 1. My Hotmail account is not monitored regularly. To send me an e-mail, please use the address shown above. 2. The SPSSX Discussion forum on Nabble is no longer linked to the SPSSX-L listserv administered by UGA (https://listserv.uga.edu/). |
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Hi Bruce (and Doc):
I have always found that using a stratified Cox regression model is much simpler than David Garson's method using NOMREG. I posted time ago a solution using COXREG: http://www.spsstools.net/Syntax/RegressionRepeatedMeasure/ConditionalLogisticRegression.txt HTH, Marta GG Bruce Weaver wrote: > Doc Ash wrote: > >> hello, >> >> i'm doing a 1:1 matched case control study, gettin confused on how to go >> about with data analysis, particularly with regards to risk factors. some >> of the risk factors are binary (yes/no), some have multiple categories >> (eg; age <20yrs, 20 - 29 yrs, 30 - 39 yrs). how do i calculate the odds >> ratios for each category?? >> am confused >> >> > > With 1:1 matching, you can perform conditional logistic regression via > NOMREG. See David Garson's notes on it here: > > http://faculty.chass.ncsu.edu/garson/PA765/logistic.htm#matchedconditional > > > > > -- For miscellaneous SPSS related statistical stuff, visit: http://gjyp.nl/marta/ ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD |
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If you need immediate assistance please contact me at 503/539-5606. Thank you.
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In reply to this post by Marta Garcia-Granero
Another option, of course, is to use generalized estimating equations (GEE) via GENLIN. I posted something to the SPSS newsgroup after using that method to reanalyze some old data that I'd analyzed with Stata the first time around. The GENLIN results from SPSS were very similar to the conditional logistic regression results from Stata. Unfortunately, I can't find that old discussion right now to give the link. But here is a comparison of the results for 4 different outcome variables. View in Courier or some other fixed font (e.g., copy and paste into a text editor). ---------------------------------------------------------- Outcome | Odds Ratio [95% Conf. Interval] METHOD ---------------------------------------------------------- Outcome 1 gp | 1.599 1.064 2.403 1 | 1.606 1.072 2.406 2 ---------------------------------------------------------- Outcome 2 gp | 1.626 1.126 2.346 1 | 1.631 1.128 2.358 2 ---------------------------------------------------------- Outcome 3 gp | 0.755 0.536 1.065 1 | 0.839 0.616 1.142 2 ---------------------------------------------------------- Outcome 4 gp | 1.579 0.734 3.340 1 | 1.585 0.735 3.419 2 ---------------------------------------------------------- Method 1: Conditional logistic regression (Stata) Method 2: GEE (via GENLIN in SPSS)
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Bruce Weaver bweaver@lakeheadu.ca http://sites.google.com/a/lakeheadu.ca/bweaver/ "When all else fails, RTFM." PLEASE NOTE THE FOLLOWING: 1. My Hotmail account is not monitored regularly. To send me an e-mail, please use the address shown above. 2. The SPSSX Discussion forum on Nabble is no longer linked to the SPSSX-L listserv administered by UGA (https://listserv.uga.edu/). |
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Hi Bruce:
Don't you remember my series of posts concerning the same topic? I finally found out that GENLIN did not work for conditional logistic regression (although it worked for conditional Poisson or log-binomial models), because the outcome can't be matched, only the exposition. Therefore, for matched case-control studies, GENLIN can't be used, although it is perfect for matched cohort-studies. Since Doc Ash metnions a matched case-control study, he can't use GENLIN, and should use conditional logistic regression, either using NOMREG, or using COXREG. Best regards, Marta GG Bruce Weaver wrote: > > Another option, of course, is to use generalized estimating equations (GEE) > via GENLIN. I posted something to the SPSS newsgroup after using that > method to reanalyze some old data that I'd analyzed with Stata the first > time around. The GENLIN results from SPSS were very similar to the > conditional logistic regression results from Stata. Unfortunately, I can't > find that old discussion right now to give the link. But here is a > comparison of the results for 4 different outcome variables. View in > Courier or some other fixed font (e.g., copy and paste into a text editor). > > ---------------------------------------------------------- > Outcome | Odds Ratio [95% Conf. Interval] METHOD > ---------------------------------------------------------- > Outcome 1 gp | 1.599 1.064 2.403 1 > | 1.606 1.072 2.406 2 > ---------------------------------------------------------- > Outcome 2 gp | 1.626 1.126 2.346 1 > | 1.631 1.128 2.358 2 > ---------------------------------------------------------- > Outcome 3 gp | 0.755 0.536 1.065 1 > | 0.839 0.616 1.142 2 > ---------------------------------------------------------- > Outcome 4 gp | 1.579 0.734 3.340 1 > | 1.585 0.735 3.419 2 > ---------------------------------------------------------- > > Method 1: Conditional logistic regression (Stata) > Method 2: GEE (via GENLIN in SPSS) > > > > ----- > -- > Bruce Weaver > [hidden email] > http://sites.google.com/a/lakeheadu.ca/bweaver/ > "When all else fails, RTFM." > > NOTE: My Hotmail account is not monitored regularly. > To send me an e-mail, please use the address shown above. > -- > View this message in context: http://old.nabble.com/matched-case-control-data-analysis-help-tp28568766p28575575.html > Sent from the SPSSX Discussion mailing list archive at Nabble.com. > > ===================== > To manage your subscription to SPSSX-L, send a message to > [hidden email] (not to SPSSX-L), with no body text except the > command. To leave the list, send the command > SIGNOFF SPSSX-L > For a list of commands to manage subscriptions, send the command > INFO REFCARD > > -- For miscellaneous SPSS related statistical stuff, visit: http://gjyp.nl/marta/ ===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD |
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Hi Marta. Now that you mention it, I do remember your series of posts, but I'll have to review them. I will make one comment now, though: I don't think the GEE approach (with GENLIN) is meant to perform conditional logistic regresssion per se; rather, I think it is considered an alternative to conditional logistic regression. The following article, for example, suggests it should be fine for analysis of correlated binary outcomes:
http://aje.oxfordjournals.org/cgi/content/abstract/157/4/364 Cheers, Bruce
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Bruce Weaver bweaver@lakeheadu.ca http://sites.google.com/a/lakeheadu.ca/bweaver/ "When all else fails, RTFM." PLEASE NOTE THE FOLLOWING: 1. My Hotmail account is not monitored regularly. To send me an e-mail, please use the address shown above. 2. The SPSSX Discussion forum on Nabble is no longer linked to the SPSSX-L listserv administered by UGA (https://listserv.uga.edu/). |
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