Tomas Aragon
2002-Feb-19 22:03 UTC
[R] exact confidence intervals for conditional logistic regression
Dear R folks, We completed a matched case-control study that was analyzed using conditional logistic regression. Because of the small sample size we need to calculate exact confidence intervals. The quick solution is to purchase LogExact by Cytel. However, we'd like to do this in R. Anyone have experience with this? Many thanks, Tomas ____________________________________ Tomas Aragon, MD, DrPH, Director Com Health Epidemiology & Disease Control San Francisco Department of Public Health Tel: (415) 554-2724, Fax: (415) 554-2848 Pgr: (415) 809-7837, Mob: (415) 706-5203 Email: tomas.aragon at sfdph.org URL: http://www.medepi.org/aragon -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
vito muggeo
2002-Feb-20 08:29 UTC
[R] exact confidence intervals for conditional logistic regression
Hi, I *suppose* that exact logistic regression is not (yet?!!?) implemented in any R software, because it should be very hard to calculate the permutational distribution; Possible alternative (beside buying LogXact) are using MCMC methods (maybe using (Win)BUGS, but I am not able to tell you anything more) or using double saddlepoint approximation to approximate the *univariate* conditional distribution: the S-Plus glm.cond() by A.Brazzale does this (I don't whether it works in R, too). However recent papers by Corcoran et al. (Stat in Med, 2001, pg. 2723) shows that this approach, sometimes produces unreliable results. Hope that this helps you, vito Please let me know if you know something more about computational aspects ----- Original Message ----- From: "Tomas Aragon" <Tomas.Aragon at sfdph.org> To: <r-help at stat.math.ethz.ch> Cc: <wayne.enanoria at sfdph.org> Sent: Tuesday, February 19, 2002 11:03 PM Subject: [R] exact confidence intervals for conditional logistic regression> Dear R folks, > We completed a matched case-control study that was analyzed using > conditional logistic regression. Because of the small sample size we need > to calculate exact confidence intervals. The quick solution is to purchase > LogExact by Cytel. However, we'd like to do this in R. Anyone have > experience with this? > > Many thanks, > Tomas > ____________________________________ > Tomas Aragon, MD, DrPH, Director > Com Health Epidemiology & Disease Control > San Francisco Department of Public Health > Tel: (415) 554-2724, Fax: (415) 554-2848 > Pgr: (415) 809-7837, Mob: (415) 706-5203 > Email: tomas.aragon at sfdph.org > URL: http://www.medepi.org/aragon > > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-> r-help mailing list -- Readhttp://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html> Send "info", "help", or "[un]subscribe" > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch >_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._. _._ -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._