# Causality Assessment Scales in Pharmacovigilance

**URL:** <https://www.medboundhub.com/t/causality-assessment-scales-in-pharmacovigilance/16259>\
**Category:** Pharmacy\
**Tags:** pharmacovigilance\
**Created:** [March 25, 2026, 12:31pm UTC](https://www.medboundhub.com/t/causality-assessment-scales-in-pharmacovigilance/16259 "2026-03-25T12:31:27Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![J.Aishwarya11](https://yyz1.discourse-cdn.com/flex033/user_avatar/www.medboundhub.com/j.aishwarya11/32/3928_2.png) [@J.Aishwarya11](https://www.medboundhub.com/u/J.Aishwarya11)\
**Post date:** [March 25, 2026, 12:31pm UTC](https://www.medboundhub.com/t/causality-assessment-scales-in-pharmacovigilance/16259/1 "2026-03-25T12:31:27Z")

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**What is Pharmacovigilance?**  
According to the WHO-- it is defined as the science and activities relating to the _detection, assessment, understanding and prevention_ of adverse effects or any other drug-related problem.

**What is Causality Assessment?**  
When a patient on a drug develops a new symptoms or sign, the key question clinician ask is- did the drug cause this? Answering it is rarely straightforward. The event might be-- because of the underlying disease, a concomitant medicine, or a true drug reaction.

**Causality assessment** - evaluating the relationship between a medicine and an adverse event to see whether the medicine actually caused it or happened due to some other reasons.

**Major Causality Assessment scale:**

1._WHO-UMC system_ – Used in the VigiBase international spontaneous reporting database. it is qualitative and algorithm-free, rely on the clinical judgment guided by the standardised criteria for each category.

2._Naranjo Algorithm (Naranjo scale) –_ was proposed by Dr. Claudia A. Naranjo and his colleagues from the University of Toronto in the year of 1981.  
this is a 10-question probabilistic questionnaire- that assign a numerical score which is to estimate the probability of an ADR. it was specifically developed to standardize the assessment of causality for all ADRs.

**Other scales include-**

RUCAM- gold standard for drug-induced liver injury (DILI).

Jones/Kramer-decision-tree based.

LCAT-structured, flow diagram-based tool-assessing ADRs in clinical setting.

 ![other scales](https://canada1.discourse-cdn.com/flex033/uploads/medbound/original/2X/6/6d1e5d1bc2cf982ff8c0567edb824cdc12a0f5a0.jpeg)  
 ![WHO-UMC scale](https://canada1.discourse-cdn.com/flex033/uploads/medbound/original/2X/1/1e421d2ac7cdac64dabe95caf0bc51e3a2dbf523.jpeg)  
 ![Naranjo scale](https://canada1.discourse-cdn.com/flex033/uploads/medbound/original/2X/1/100d8c097e772e9e14959305439c24751d58b384.png)

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**Author:** ![Sadia](https://yyz1.discourse-cdn.com/flex033/user_avatar/www.medboundhub.com/sadia/32/4179_2.png) [@Sadia](https://www.medboundhub.com/u/Sadia)\
**Post date:** [April 2, 2026, 2:05pm UTC](https://www.medboundhub.com/t/causality-assessment-scales-in-pharmacovigilance/16259/2 "2026-04-02T14:05:57Z")

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Informative post @J.Aishwarya11

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**Author:** ![Drjulietruby](https://yyz1.discourse-cdn.com/flex033/user_avatar/www.medboundhub.com/drjulietruby/32/3857_2.png) [@Drjulietruby](https://www.medboundhub.com/u/Drjulietruby)\
**Post date:** [April 2, 2026, 5:40pm UTC](https://www.medboundhub.com/t/causality-assessment-scales-in-pharmacovigilance/16259/3 "2026-04-02T17:40:49Z")

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Simple and clear explanation… Good information…