Among the actions in its final rule CMS-1498-F ("Changes to the Hospital Inpatient Prospective Payment System End Fiscal Year 2011"), issued on July 30, the Centers for Medicare & Medicaid Services have changed the severity level change to diagnosis code 584.9 (Acute kidney failure, unspecified) from the MCC to CC list, effective October 1, 2010. The more precise acute renal failure codes will remain on the MCC list.
CMS commented that inconsistent use of the term acute renal failure (ARF) and lack of standardization for clinical documentation underlie the findings of a Medicare claims data analysis showing patients with this code (584.9) as a secondary diagnosis are similar to those who are at a CC level. CMS said it did not believe it is appropriate to defer a decision on reclassification of the severity level of this code until future coding or guideline modifications can be considered because the Medicare claims data clearly support the change.
Some commenters objected to the change outlined in the earlier proposed rule because of the financial impact this change would have on their hospitals, several estimating a reduction of 2 percent or more in total Medicare payments. CMS responded it is not “appropriate to inflate payments for hospitals that report a higher incidence of this code, yet are treating patients with a lower severity level.”
Primaris issued documentation guidelines
The CMS rule comes six months after Primaris distributed to physician-endorsed ARF documentation criteria to all Missouri acute care facilities that Primaris physicians reviewers are applying to Medicare case reviews for Diagnosis Related Group (DRG) validation that contain ARF as a secondary diagnosis to ensure that the diagnostic and procedural codes billed are supported by the documentation in the medical record.
With implementation of Medical Severity (MS) DRGs, Primaris noted in Missouri the proportion of these acute care inpatient claims increased nearly 60 percent from September 2007 to June 2009, climbing to a high of 12% in December 2009. A subsequent Primaris analysis of Medicare claims showed that between Oct. 2007 and Mar. 2010, an average of 2,449 Medicare inpatient hospitalizations per month in Missouri were found to be associated with an ARF diagnosis in the claim. Given a range in the denial rate for this diagnosis of 12.8% to 18.8% for all reviewed cases submitted for higher-weighted DRGs, we estimated a total annualized overpayment error in the range of $9-13 million. Meanwhile, since Primaris released the documentation guidelines last December, we have seen a slight downward trend in the proportion of ARF acute care inpatient claims to 10.9 percent in May 2010. Primaris will continue to apply the documentation guidelines to higher-weighted DRG validation case reviews with a secondary diagnosis of ARF (code 584.9) at least until the end of 2010.
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CMS changes severity level of diagnosis code for Acute Kidney Failure
