BACKGROUND: The International Statistical Classification of Diseases and Related 
Health Problems (ICD) is currently undergoing a revision process to develop the 
Eleventh Revision (ICD-11), but substantial modification of chapter 19 has not 
been proposed despite its known problems in describing injury severity and 
multiple injuries. Many facilities treating trauma patients perform duplicate 
coding for trauma diagnoses using two different classification systems, the ICD 
for administrative purposes and the Abbreviated Injury Scale (AIS) for trauma 
registry, because unambiguous conversion of codes between the ICD and AIS is not 
always possible due to structural differences.
AIM: We developed a new bridging classification system which can be 
unambiguously converted to both ICD and AIS.
METHODS AND RESULTS: The bridging classification adopted multidimensional coding 
and addressed differences in granularity and classification boundaries by 
adopting the more detailed categorizations whenever the granularity and 
classification boundaries differed between the ICD and AIS. Then we showed that 
the bridging classification codes could unambiguously converted to both ICD and 
AIS.
CONCLUSION: Once injuries are coded using the bridging classification, the ICD 
and AIS codes are readily available. Integrating the new bridging classification 
into the ICD-11, possibly as a clinical modification, would eliminate the 
necessity of complicated procedures for code conversion and duplicate coding, 
and benefit users by building on the strengths of both the ICD and AIS.