# Warning message brms\_multiple

**URL:** <https://discourse.mc-stan.org/t/warning-message-brms-multiple/39422>\
**Category:** Modeling\
**Created:** [May 5, 2025, 2:36pm UTC](https://discourse.mc-stan.org/t/warning-message-brms-multiple/39422 "2025-05-05T14:36:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Celine\_Havermans](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/celine_havermans/32/20411_2.png) [@Celine\_Havermans](https://discourse.mc-stan.org/u/Celine_Havermans)\
**Post date:** [May 5, 2025, 2:36pm UTC](https://discourse.mc-stan.org/t/warning-message-brms-multiple/39422/1 "2025-05-05T14:36:22Z")

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Hi All,

I am using brms\_multiple to include 20 imputed data sets in my model. After running the model the Rhat and ESS seem OK (all \<1.04 and \>1000). But I do get a warning message:

Warning message:  
The displayed Rhat and ESS estimates should not be trusted for brm\_multiple models. Please see ?brm\_multiple for how to assess convergence of such models.

> 

Why should I not trust my results, I cannot find the anwser online. I am new to the brms package so any advise would really help my project. Thanks in advance!

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**Author:** ![AlesVomacka](https://avatars.discourse-cdn.com/v4/letter/a/3be4f8/32.png) [@AlesVomacka](https://discourse.mc-stan.org/u/AlesVomacka)\
**Post date:** [May 5, 2025, 3:15pm UTC](https://discourse.mc-stan.org/t/warning-message-brms-multiple/39422/2 "2025-05-05T15:15:35Z")

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Hi Celine,  
I recommend reading [brms’ vignette for missing data imputation](https://cran.r-project.org/web/packages/brms/vignettes/brms_missings.html). Specifically:

> In the summary output, we notice that some `Rhat` values are higher than 1.1 indicating possible convergence problems. For models based on multiple imputed data sets, this is often a **false positive** : Chains of different submodels may not overlay each other exactly, since there were fitted to different data… Such non-overlaying chains imply high `Rhat` values without there actually being any convergence issue. Accordingly, we have to investigate the convergence of the submodels separately.

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<div class="post-metadata">

**Author:** ![Celine\_Havermans](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/celine_havermans/32/20411_2.png) [@Celine\_Havermans](https://discourse.mc-stan.org/u/Celine_Havermans)\
**Post date:** [May 5, 2025, 4:48pm UTC](https://discourse.mc-stan.org/t/warning-message-brms-multiple/39422/3 "2025-05-05T16:48:17Z")

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Thankyou AlesVomacka,

That overview helps a lot!