I am trying to use 'network import' command to conduct a multiple treatment network meta-analysis. Some of the studies have multiple doses/treatment arms. I am setting up my data as follows:
Where study 1 is comparing drug a to place. study 2 is a multi-arm trial comparing drug b, dose 1 to placebo and drug b, dose 2 to placebo. study 3 is a multiarm trial comparing drug c, dose 1 to placebo and drug c, dose 2 to placebo. effect size and stderr reflect the estimates for mean effect and standard error for each comparison. I am setting up the data this way so that I do not have to estimate the covariance structure for the multi-arm trials, since the stata help file indicates that the network import command will do this in the background.
However, I am running into an error where stata says:
. network import, study(study) treat(trt1 trt2) effect(fev_effect) stde(fev_se)
Importing from pairs format
Reference treatment: drugc_2
All treatments: drugc_2 drugc_1 drugb_2 drugb_1 druga
1 contradiction in 5 observations
assertion is false
So, it is selecting drugc_2 instead of placebo as my main reference comparator, which doesn't allow for comparisons across other studies.
Does anyone know how to circumvent this issue? I am wanting to have placebo as the reference treatment for all studies.
Thanks in advance!
study | treatment1 | treatment2 | effect_size | stderr |
1 | placebo | druga | .5 | .2 |
2 | placebo | drugb_1 | .3 | .1 |
2 | placebo | drugb_2 | .9 | .05 |
3 | placebo | drugc_1 | .4 | .2 |
3 | placebo | drugc_2 | .5 | .3 |
However, I am running into an error where stata says:
. network import, study(study) treat(trt1 trt2) effect(fev_effect) stde(fev_se)
Importing from pairs format
Reference treatment: drugc_2
All treatments: drugc_2 drugc_1 drugb_2 drugb_1 druga
1 contradiction in 5 observations
assertion is false
So, it is selecting drugc_2 instead of placebo as my main reference comparator, which doesn't allow for comparisons across other studies.
Does anyone know how to circumvent this issue? I am wanting to have placebo as the reference treatment for all studies.
Thanks in advance!
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