For loops to make leave-one-out analysis with netmeta-CodePudding

I'm doing a network metanalysis of 29 studies using the "netmeta" package with R and I now have to do the leave-one-out analysis. I was thus wondering wether there is a way to use for loops to gain the results of such method in order not to do it by manually excluding one trial at the time.

I came up with this:

 for (i in 1:29){
  NMA_DB_L<-NMA_DB[-i,]
  yi_All_cause<-summary(escalc(ai= NMA_DB_L$All_Cause_d_C, bi=NMA_DB_L$PTS_All_Cause_d_C - NMA_DB_L$All_Cause_d_C,
                               ci= NMA_DB_L$All_Cause_d_I, di= NMA_DB_L$PTS_All_Cause_d_I - NMA_DB_L$All_Cause_d_I, 
                               measure = "RR"))[,"yi"]
  
 sei_All_cause<-summary(escalc(ai= NMA_DB_L$All_Cause_d_C, bi=NMA_DB_L$PTS_All_Cause_d_C - NMA_DB_L$All_Cause_d_C,
                               ci= NMA_DB_L$All_Cause_d_I, di= NMA_DB_L$PTS_All_Cause_d_I - NMA_DB_L$All_Cause_d_I, 
                               measure = "RR"))[,"sei"]
  
  netmeta(TE=yi_All_cause, seTE =  sei_All_cause, treat1 = NMA_DB_L$Arm_1, treat2 = NMA_DB_L$INT, sm="RR",
          studlab = NMA_DB_L$Study, reference.group = "Standard_DAPT")
}

and it seems to work properly, but I cannot find a way to save the results of each analysis without one of the trials.

Does anyone have an idea of how to do so?

Thanks in advice.

CodePudding user response：

Why not save the outputs of netmeta function into a list?

# Create list of length 29
net_results <- vector('list', 29)

for (i in 1:29) {
    NMA_DB_L<-NMA_DB[-i,]

    ...

    net <- netmeta(TE=yi_All_cause, seTE =  sei_All_cause,
            treat1 = NMA_DB_L$Arm_1, treat2 = NMA_DB_L$INT, sm="RR",
            studlab = NMA_DB_L$Study, reference.group = "Standard_DAPT")
    net_results[[i]] <- net
}

You can then access results of the specific run with net_results[[1]] etc.

R lists can in general contain any type of element which makes it a suitable structure for this type of problems.