Evaluation of naranjo adverse drug reactions probability scale in causality assessment of drug-induced liver injury.
BACKGROUND
Causality assessment in hepatotoxicity is challenging. The current standard liver-specific Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale is complex and difficult to implement in daily practice. The Naranjo Adverse Drug Reactions Probability Scale is a simple and widely used nonspecific scale, which has not been specifically evaluated in drug-induced liver injury.


OBJECTIVE
To compare the Naranjo method with the standard liver-specific Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale in evaluating the accuracy and reproducibility of Naranjo Adverse Drug Reactions Probability Scale in the diagnosis of hepatotoxicity.


METHODS
Two hundred and twenty-five cases of suspected hepatotoxicity submitted to a national registry were evaluated by two independent observers and assessed for between-observer and between-scale differences using percentages of agreement and the weighted kappa (kappa(w)) test.


RESULTS
A total of 249 ratings were generated. Between-observer agreement was 45% with a kappa(w) value of 0.17 for the Naranjo Adverse Drug Reactions Probability Scale, while there was a higher agreement when using the Council for International Organizations of Medical Sciences/Roussel Uclaf Causality Assessment Method scale (72%, kappa(w): 0.71). Concordance between the two scales was 24% (kappa(w): 0.15). The Naranjo Adverse Drug Reactions Probability Scale had low sensitivity (54%) and poor negative predictive value (29%) and showed a limited capability to distinguish between adjacent categories of probability.


CONCLUSIONS
The Naranjo scale lacks validity and reproducibility in the attribution of causality in hepatotoxicity.
García-Cortés
M
M
Unidad de Hepatología, Servicio de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, Facultad de Medicina, Campus Universitario de Teatinos sn, Málaga, Spain.
Lucena
M I
MI
Pachkoria
K
K
Borraz
Y
Y
Hidalgo
R
R
Andrade
R J
RJ
D016907:Adverse Drug Reaction Reporting Systems / Q000592:standards*; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology*; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D008099:Liver / Q000187:drug effects*; D008111:Liver Function Tests / Q000379:methods; D012720:Severity of Illness Index; D013030:Spain; D013223:Statistics as Topic; D018675:Toxicity Tests / Q000592:standards*