A 90 year old patient is admitted to the hospital with community acquired pneumonia. During the course of hospitalization, the patient develops some aphasia and a stroke is suspected. A CT scan is inconclusive and a MRI is unable to be done as the patient has a pacemaker. The physician signs out the final diagnoses as: community acquired pneumonia, TIA vs. CVA, hypertension, dementia, and mitral valve prolapse.
Do the rules for coding contrasting/comparative diagnoses apply to secondary diagnoses as well?
Here are my thoughts…
- Coding Clinic guidelines (2Q 2002 p. 64-65) indicate when there are two or more comparative or contrasting conditions documented as “either/or” (or similar terminology), they are coded as if the diagnoses were confirmed.
- However, Coding Clinic (1Q 1998, p. 9) clarifies that the contrasting or comparative coding guideline only applies to the selection of the principal diagnosis.
- Further review of the 2002 guidelines mentioned above indicates in the title of section II that the guidelines apply to selection of principal diagnoses for acute care inpatient facilities.
- In our case scenario above, the coder would only code the aphasia (784.3).
This is an important guideline to remember as incorrect coding in similar situations could have significant reimbursement implications. In our example, had the principal diagnosis contrasting/comparative guideline been applied to the secondary diagnoses, the patient’s DRG would change from a non-CC/non-MCC Medicare DRG (195) with weight of 0.7078 to a MCC Medicare DRG (193) with a weight of 1.4893.
What are your thoughts?