# How Vault Calculates Dechallenge

Upon _Case Assessment_ generation, Vault calculates <a href="/en/gr/01287/#dechallenge">_Dechallenge_</a> values. For the calculation, Vault considers the following fields:

* <a href="/en/gr/01287/#event-outcome">_Outcome_</a> on _Case Adverse Events_
* <a href="/en/gr/01287/#action-taken">_Action Taken_</a> on _Case Products_

You can override Vault-populated values using the <a href="/en/gr/01287/#dechallenge-override">_Dechallenge Override_</a> field on _Case Assessments_. Vault exports _Dechallenge_ and _Dechallenge Override_ values to <a href="/en/gr/823290/">NMPA E2B(R3)</a>, <a href="/en/gr/01222/">CIOMS I</a>, and <a href="/en/gr/802644/">FDA MedWatch 3500A</a> files.

### Dechallenge Calculation Criteria

Vault calculates and applies _Dechallenge_ values on _Case Assessments_ that meet all of the criteria as follows:

* _Dechallenge_ is _Unknown_ when:
    * The _Outcome_ of the _Case Adverse Event_ is unknown
    * The _Action Taken_ of the _Case Product_ is one of: 
        * _Unknown_
        * _Drug withdrawn_
        * _Drug reduced_
* _Dechallenge_ is _Yes_ when: 
    * The _Outcome_ of the _Case Adverse Event_ is one of:
        * _recovered/resolved_
        * _recovering/resolving_
        * _recovered/resolved with sequelae_
    * The _Action Taken_ of the _Case Product_ is one of: 
        * _Drug withdrawn_
        * _Drug reduced_
* _Dechallenge_ is _No_ when:
    * The _Outcome_ of the _Case Adverse Event_ is one of:
        * _not recovered/not resolved/ongoing_
        * _Fatal_
    * The _Action Taken_ of the _Case Product_ is one of: 
        * _Drug withdrawn_
        * _Drug reduced_

For all other combinations of _Outcome_ and _Action Taken_, Vault populates _Not Applicable_ in the _Dechallenge_ field. If either the _Outcome_ or _Action Taken_ fields are blank or include a custom value, Vault does not populate a _Dechallenge_ value.

### Assessment Dechallenge Recalculations {#recalculations}

Vault recalculates _Dechallenge_ values when you:

* Add or edit:
    * _Outcome_ on _Case Adverse Events_
    * _Action Taken_ on _Case Products_
* Run the _Generate Assessments_ action
* Unblind _Case Products_

Vault copies _Dechallenge_ values instead of recalculating them when you:

* Create follow-up _Cases_ by running the _Create Follow Up Case_ action
* Bulk unblind _Cases_

Depending on your Admin's <a href="/en/gr/740208/#auto-calc">configuration</a>, when Vault recalculates _Dechallenge_ values on _Case Assessments_ with _Dechallenge Override_ values, Vault may clear _Dechallenge Override_ values.