Several causality methods are developed from a theoretical perspective. In daily practice, not all information requested by the causality method is relevant or available, decreasing their applicability. Lareb developed a new causality documentation tool (CausDoc) where an algorithm, taking into account the information present in the report, combined with expert judgement, determines the causality. CausDoc can be used for reports on drugs and vaccines.
CausDoc provides nine structured questions relevant for causality assessment. If the needed information in order to answer the question is available, the questions will be part of the causality algorithm, if the information is not present, the question will not be a part of the causality algorithm. Subsequently, these questions are answered based on the information present and a the causality is calculated. The causality outcome is based on the sum score of all answers divided by the included questions where: ≤30%: unlikely; 31-70%: possible; 71-90%: probable and >90%: certain. If needed, this outcome can be adjusted up or down by one category based on expert judgement, provided with a reason.
The first experiences with this tool are promising. CausDoc shows higher sensitivity and specificity compared to the Naranjo algorithm and the WHO adverse events following immunization (AEFI) criteria.
Reference: Oosterhuis I, Zweers P, Rümke H, Muller‐Hansma A, van Puijenbroek E. A tailor‐made approach for causality assessment for ADR reports on drugs and vaccines. Pharmacoepidemiol Drug Saf. 2018;1–7.