Hello all, I have a table like this, with ~300 individuals: Famid Id Faid Moid Cohort Sex Survival Event SNP1 SNP2 SNP3 1 1 0 0 0 0 10 1 0 1 0 2 2 0 0 1 1 20 1 0 0 0 2 3 0 0 0 0 25 1 0 1 0 4 5 1 2 0 0 35 1 0 1 1 4 6 1 2 0 0 35 0 1 0 1 famid=family id, id=id of person,faid=father id,moid=mother id. My question of interest: What impact does SNP1/SNP2/SNP3 have on survival of individuals (Id), after accounting for possible effects due to family relatedness (Famid). So I want to account for family-specific frailty effects, and individual frailty effects according to degree of relationship between individuals. The commands I've used are: Library(survival) Library(coxme) Library(kinship2) Library(bdsmatrix) Death.dat <-read.table(?Table?,header=T) deathdat.kmat <-makekinship(famid=death.dat$famid,id=death.dat$id,father=death.dat$faid,mother=death.dat$moid) death.dat1<-subset(death.dat,!is.na(Survival)) all <-dimnames(deathdat.kmat)[[1]] temp <-which(!is.na(death.dat$Survival[match(all,death.dat$id)])) deathdat1.kmat <-deathdat.kmat[temp,temp] model4 <-coxme(Surv(Survival,Event)~Sex+strata(Cohort)+SNP1+SNP2+SNP3,data=death.dat1,id|famid,varlist=list(deathdat1.kmat,famblockf.mat),pdcheck=FALSE) I almost completely edited these commands from : http://www.ncbi.nlm.nih.gov/pubmed/21786277 as I am new to R. The error I obtain is: Error in coxme(Surv(Survival, Event) ~ Sex + strata(Cohort) + SNP1 + SNP2 + : No observations remain in the data set In addition: Warning message: In Ops.factor(id, famid) : | not meaningful for factors I have two questions: 1. What is the difference between (id|famid) and (1+id|famid)/How to I tell which is appropriate for my data set/Have I formatted that section of the command properly? 2. Does anyone understand the error/how to fix it? Many thanks [[alternative HTML version deleted]]