The code used to identify the 1st external cause of injury, poisoning, or other adverse effect.
On October 1, 2015 the conversion from the 9th version of the International Classification of Diseases (ICD-9-CM) to version 10 (ICD-10-CM) occurred. ICD-10 has more than 70,000 unique diagnosis codes compared to approximately 14,000 ICD-9 codes, which allows for more detail surrounding diagnoses.
For ICD-9 diagnosis codes, this is a 3-5 digit numeric or alpha/numeric value; it can include leading zeros.
The lower the number in the variable name, the more important the diagnosis in the patient treatment/billing (i.e., ICD_DGNS_E_CD1 is considered more important than ICD_DGNS_E_CD9).
Source: Medicare Advantage Organizations (MAOs)