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Safety Monitoring of Medicinal Products: Guidelines for Setting Up and Running a Pharmacovigilance Centre
(2000; 28 pages) [French]
Table of Contents
View the documentINTRODUCTION
View the document1. WHY PHARMACOVIGILANCE?
View the document2. DEFINITION AND AIMS
Open this folder and view contents3. HOW TO START A PHARMACOVIGILANCE CENTRE
Open this folder and view contents4. REPORTING OF ADVERSE DRUG REACTIONS
Open this folder and view contents5. SPECIAL ISSUES IN REPORTING
Open this folder and view contents6. PRACTICALITIES IN THE ORGANISATION OF A PHARMACOVIGILANCE CENTRE
Open this folder and view contents7. ASSESSMENT OF CASE REPORTS
Open this folder and view contents8. USE OF THE DATA
Open this folder and view contents9. RELATIONS WITH OTHER PARTIES
View the document10. OTHER SOURCES OF INFORMATION
View the document11. FUNDING
View the documentREFERENCES
View the documentGLOSSARY
View the documentCAUSALITY CATEGORIES
View the documentWHO CONTACTS
 

CAUSALITY CATEGORIES

The causality categories described by the Uppsala Monitoring Centre are as follows:

1. Certain: a clinical event, including laboratory test abnormality, occurring in a plausible time relationship to drug administration, and which cannot be explained by concurrent disease or other drugs or chemicals. The response to withdrawal of the drug (dechallenge) should be clinically plausible. The event must be definitive pharmacologically or phenomenologically, using a satisfactory rechallenge procedure if necessary.

2. Probable/Likely: a clinical event, including laboratory test abnormality, with a reasonable time sequence to administration of the drug, unlikely to be attributed to concurrent disease or other drugs or chemicals, and which follows a clinically reasonable response on withdrawal (dechallenge). Rechallenge information is not required to fulfil this definition.

3. Possible: a clinical event, including laboratory test abnormality, with a reasonable time sequence to administrations of the drug, but which could also be explained by concurrent disease or other drugs or chemicals. Information on drug withdrawal may be lacking or unclear.

4. Unlikely: a clinical event, including laboratory test abnormality, with a temporal relationship to drug administration which makes a causal relationship improbable, and in which other drugs, chemicals or underlying disease provide plausible explanations.

5. Conditional/Unclassified: a clinical event, including laboratory test abnormality, reported as an adverse reaction, about which more data is essential for a proper assessment, or the additional data is under examination.

6. Unassessable/Unclassifiable: a report suggesting an adverse reaction which cannot be judged because information is insufficient or contradictory, and which cannot be supplemented or verified.

As a step towards harmonisation in drug regulation in the countries of the European Union, the EU pharmacovigilance working parties proposed the following three causality categories:

Category A: ‘Reports including good reasons and sufficient documentation to assume a causal relationship, in the sense of plausible, conceivable, likely, but not necessarily highly probable’.

CategoryB: ‘Reports containing sufficient information to accept the possibility of a causal relationship, in the sense of not impossible and not unlikely, although the connection is uncertain and may be even doubtful, e.g. because of missing data, insufficient evidence or the possibility of another explanation’.

CategoryO: ‘Reports where causality is, for one or another reason, not assessable, e.g. because of missing or conflicting data’.

Sources

Edwards IR, Biriell C. Harmonisation in pharmacovigilance.
Drug Safety 1994,10:93-102.

Bégaud B, Evreux JC, Jouglard J, Lagier G. Unexpected or toxic drug reaction assessment (imputation). Actualisation of the method used in France.
Thérapie 1985;40:111-8.

Meyboom RHB, Hekster YA, Egberts ACG, Gribnau FWJ, Edwards IR.
Causal or casual? The role of causality assessment in pharmacovigilance.
Drug Safety 1997,16:374-389.

Meyboom RHB, Egberts ACG, Edwards IR, Hekster YA, De Koning FHP, Gribnau FWJ. Principles of signal detection in pharmacovigilance.
Drug Safety 1997; 16:355-365.

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