Quote from VigiServe Admin on November 27, 2020, 8:40 AM

In the case of Veterinary Medicinal Products (VMP), the preferred method of causality assessment is using the ‘ABON’ system, where

A - stands for Probable,

B - stands for Possible,

O - stands for Unclassifiable/insufficient data,

O1 - stands for Inconclusive,

N - stands for Unlikely

 

The six main factors that are considered for the causality assessment, are:

1. Associative Connection

2. Pharmacological and/or immunological explanation

3. Clinical or pathological phenomena,

4. Previous knowledge,

5. Other Causes, and

6. Reliability of data.

If the answers to the first four factors are Yes, then it is likely to be A or B, while a Yes for fifth and sixth factor, may mean otherwise.