In the absence of code linkage, the CHADx algorithm was programmed to locate the first 'Y' code which follows a 'T' or 'End of Chapter' (Jackson et al.
The scenario is represented by the codes below and, without explicit code linkage, must give rise to double counting, if all septicaemia is to be captured.
With better code linkage, further coded conditions could be selectively excluded from the CHADx on the basis that they are recorded only due to the presence of another condition.
Changes to methods for code linkage to identify an 'event,' would improve the classification.
Eponyms can be added to diagnosis or procedure lists; code linkages
can be added, deleted, or changed; "hot keys" sequences can be changed; and local HCPCS codes can be added, to cite just a few.