Hi, I am running the following model: fit1.full <- coxme(Surv(age_sym1, sym1) ~ sex + lifedxm*sex + (1|famid), data=bip.surv) I would like to extract the AIC from that object to calculate the AICC. However, when I look at str(fit1.full) and summary(fit1.full) (pasted below) I don't see anything that would allow me to get pull the AIC out from that object. Is there a way to retrieve the AIC from a coxme object? Please cc me on your response. Thanks, Chris 1> str(fit1.full) List of 20 $ coefficients :List of 2 ..$ fixed : Named num [1:5] 0.197 -1.132 -0.499 0.114 -0.329 .. ..- attr(*, "names")= chr [1:5] "sexMALES" "lifedxmCONTROL" "lifedxmMAJOR" "sexMALES:lifedxmCONTROL" ... ..$ random:List of 1 .. ..$ famid: Named num 0.964 .. .. ..- attr(*, "names")= chr "Intercept" $ frail :List of 1 ..$ famid: Named num [1:97] -0.8144 -0.6222 -0.0979 0.5179 -0.5587 ... .. ..- attr(*, "names")= chr [1:97] "1" "2" "3" "4" ... $ penalty : num 22.6 $ loglik : Named num [1:3] -479 -467 -435 ..- attr(*, "names")= chr [1:3] "NULL" "Integrated" "Penalized" $ variance :Formal class 'bdsmatrix' [package "bdsmatrix"] with 6 slots .. ..@ blocksize: int [1:97] 1 1 1 1 1 1 1 1 1 1 ... .. ..@ blocks : num [1:97] 0.545 0.606 0.485 0.415 0.636 ... .. ..@ rmat : num [1:102, 1:5] -0.00096 -0.000778 -0.000286 0.000102 -0.000688 ... .. ..@ offdiag : num 0 .. ..@ Dim : int [1:2] 102 102 .. ..@ Dimnames :List of 2 .. .. ..$ : NULL .. .. ..$ : NULL $ df : num [1:2] 6 49.3 $ hmat :Formal class 'gchol.bdsmatrix' [package "bdsmatrix"] with 6 slots .. ..@ blocksize: int [1:97] 1 1 1 1 1 1 1 1 1 1 ... .. ..@ blocks : num [1:97] 1.87 1.68 2.12 2.47 1.61 ... .. ..@ rmat : num [1:102, 1:5] -0.1885 0.0659 -0.2205 -0.0816 -0.1502 ... .. ..@ rank : int 102 .. ..@ Dim : int [1:2] 102 102 .. ..@ Dimnames :List of 2 .. .. ..$ : NULL .. .. ..$ : NULL $ iter : num [1:2] 10 54 $ control :List of 6 ..$ eps : num 1e-08 ..$ toler.chol : num 1.82e-12 ..$ iter.max : num 20 ..$ inner.iter : num 5 ..$ sparse.calc: num 1 ..$ optpar :List of 2 .. ..$ method : chr "BFGS" .. ..$ control:List of 1 .. .. ..$ reltol: num 1e-05 $ u : num [1:102] 2.70e-05 2.02e-05 1.48e-05 -1.61e-05 1.78e-05 ... $ means : num [1:5] 0.45 0.307 0.444 0.148 0.206 $ scale : num [1:5] 0.495 0.425 0.494 0.252 0.328 $ linear.predictor: num [1:189] -1.313 -1.313 -1.754 -1.443 -0.597 ... $ n : num [1:2] 99 189 $ terms :Classes 'terms', 'formula' length 3 Surv(age_sym1, sym1) ~ sex + lifedxm * sex .. ..- attr(*, "variables")= language list(Surv(age_sym1, sym1), sex, lifedxm) .. ..- attr(*, "factors")= int [1:3, 1:3] 0 1 0 0 0 1 0 1 1 .. .. ..- attr(*, "dimnames")=List of 2 .. .. .. ..$ : chr [1:3] "Surv(age_sym1, sym1)" "sex" "lifedxm" .. .. .. ..$ : chr [1:3] "sex" "lifedxm" "sex:lifedxm" .. ..- attr(*, "term.labels")= chr [1:3] "sex" "lifedxm" "sex:lifedxm" .. ..- attr(*, "specials")=Dotted pair list of 2 .. .. ..$ strata : NULL .. .. ..$ cluster: NULL .. ..- attr(*, "order")= int [1:3] 1 1 2 .. ..- attr(*, "intercept")= num 1 .. ..- attr(*, "response")= int 1 .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> $ formulaList :List of 2 ..$ fixed :Class 'formula' length 3 Surv(age_sym1, sym1) ~ sex + lifedxm * sex .. .. ..- attr(*, ".Environment")=<environment: R_GlobalEnv> ..$ random:List of 1 .. ..$ : language, mode "(": (1 | famid) $ na.action :Class 'omit' Named int [1:3] 27 101 102 .. ..- attr(*, "names")= chr [1:3] "27" "101" "102" $ y : Surv [1:189, 1:2] 16.13+ 19.33+ 16.55+ 19.37+ 5.77 21.51 6.18 10.47 16.46+ 19.95+ ... ..- attr(*, "dimnames")=List of 2 .. ..$ : chr [1:189] "1" "2" "3" "4" ... .. ..$ : chr [1:2] "time" "status" ..- attr(*, "type")= chr "right" $ call : language coxme(formula = Surv(age_sym1, sym1) ~ sex + lifedxm * sex + (1 | famid), data = bip.surv) $ ties : chr "efron" - attr(*, "class")= chr "coxme" 1> summary(fit1.full) Length Class Mode coefficients 2 -none- list frail 1 -none- list penalty 1 -none- numeric loglik 3 -none- numeric variance 1 bdsmatrix S4 df 2 -none- numeric hmat 1 gchol.bdsmatrix S4 iter 2 -none- numeric control 6 -none- list u 102 -none- numeric means 5 -none- numeric scale 5 -none- numeric linear.predictor 189 -none- numeric n 2 -none- numeric terms 3 terms call formulaList 2 -none- list na.action 3 omit numeric y 378 Surv numeric call 3 -none- call ties 1 -none- character -- Christopher David Desjardins PhD student, Quantitative Methods in Education MS student, Statistics University of Minnesota 192 Education Sciences Building http://cddesjardins.wordpress.com