Validity study of a new diagnostic scale for drug-induced liver injury in Japan-comparison with two previous scales.

There are no specific diagnostic markers for drug-induced liver injury (DILI), a disease that is unpredictable and occasionally fatal. A new diagnostic scale, the DDW-J scale, was recently proposed in Japan, by modifying the International Consensus Meeting (ICM) scale in the items concerning chronologic criteria, concomitant drug(s), and extrahepatic manifestations. In order to determine the validity of the DDW-J scale, we assessed 127 patients (81 patients with DILI and 46 control patients) received a total of 423 drugs. When patients were assessed as 'highly probable' or 'probable', the DDW-J scale had higher sensitivity and slightly lowers specificity than the ICM scale (93.8% versus 77.8% and 89.1% versus 100%). The DDW-J scale was able to accurately diagnose DILI in some cases that were overlooked using the ICM scale. While the weighted statistical test indicated a poor correlation between the ICM and the DDW-J scales, receiver operating characteristic curves revealed that these two were superior to the Maria and Victorino scale. Future work still must be done using statistical evidence to refine the weights of individual parameters. However, the results from our study indicate that the DDW-J scale is a powerful tool with potentially important clinical applications in the diagnosis of DILI.