Can there be duplicate EHR information?

Question: When I am looking through the dataset for conditions, I see a mix of ICD9CM and ICD10CM codes when they are available. For cases like these could there be duplicate EHR information under the same ICD9CM and ICD10CM code?

Answer: It is a low probability for a Health Provider Organization (HPO) to have entered both an ICD9 and ICD10 code for the same condition for a participant. However, there usually is a standard code (SNOMED) to complement a source code (ICD9/10). It is important to check the concept’s date/datetime association to determine if entries are duplicates.