CMS Revises and Details Extrapolation Rules: Part II

Part II continues to explain the nuances in the changes made by CMS to its statistical sampling methodology.

The Centers for Medicare & Medicaid Services (CMS) recently made significant changes in its statistical sampling methodology for overpayment estimation. Effective Jan. 2, 2019, CMS radically changed its guidance on the use of extrapolation in audits by Recovery Audit Contractors (RACs), Medicare Administrative Contractors (MACs), Unified Program Integrity Contractors (UPICs), and the Supplemental Medical Review Contractor (SMRC).

The RAC program was created through the Medicare Modernization Act of 2003 (MMA) to identify and recover improper Medicare payments paid to healthcare providers under fee-for-service (FFS) Medicare plans. The RAC auditors review a small sample of claims, usually 150, and determine an error rate. That error rate is attributed to the universe, which is normally three years, and extrapolated to that universe. Extrapolation is similar to political polls – in that a Gallup poll will ask the opinions of 1-2 percent of the U.S. population, yet will extrapolate those opinions to the entire country.

First, I would like to address a listener’s question regarding the dollar amount’s factor in extrapolation cases. I recently wrote, “for example, if 500 claims are reviewed and one is found to be noncompliant for a total of $100, then the error rate is set at 20 percent.”

I need to explain that the math here is not “straight math.” The dollar amount of the alleged noncompliant claims factors into the extrapolation amount. If the dollar amount did not factor into the extrapolation, then a review of 500 claims with one non-compliant claim is 0.2 percent. The fact that, in my hypothetical, the one claim’s dollar amount equals $100 changes the error rate from 0.2 percent to 20 percent.

Secondly, the new rule includes provisions implementing the additional Medicare Advantage telehealth benefit added by the Bipartisan Budget Act of 2018. Prior to the new rule, audits were limited in the telehealth services they could include in their basic benefit packages because they could only cover the telehealth services available under the FFS Medicare program. Under the new rule, telehealth becomes more prominent in basic services. Telehealth is now able to be included in the basic benefit packages for any Part B benefit that the plan identifies as “clinically appropriate,” to be furnished electronically by a remote physician or practitioner.

The pre-Jan. 2, 2019 approach to extrapolation employed by RACs was inconsistent, and often statistically invalid. This often resulted in drastically overstated overpayment findings that could bankrupt a physician practice. The method of extrapolation is often a major issue in appeals, and the, new rules address many providers’ frustrations and complaints about the extrapolation process. This is not to say that the post-Jan. 2, 2019 extrapolation approach is perfect…far from it. But the more detailed guidance by CMS just provides more ways to defend against an extrapolation if the RAC auditor veers from instruction.

Thirdly, hiring an expert is a key component in debunking an extrapolation. Your attorney should have a relationship with a statistical expert. Keep in mind the following factors when choosing an expert:

• Price (more expensive is not always better, but expect the hourly rate to increase for trial testimony).
• Intelligence (his/her CV should tout a prestigious educational background).
• Report (even though he/she drafts a report, the report is not a substitute for testimony).
• Clusters (watch out for a sample that has a significant number of higher reimbursed claims. For example, if you generally use three CPT codes at an equal rate and the sample has an abnormal amount of the higher reimbursed claim, then you have an argument that the sample is an invalid example of your claims.
• Sample (the sample must be random and must not contain claims not paid by Medicaid).
• Oral skills (can he/she make statistics understandable to the average person?)

Fourthly, the new revised rule redefines the universe.

In the past, suppliers have argued that some of the claims (or claim lines) included in the universe were improperly used for purposes of extrapolation. However, the pre-Jan. 2, 2019 Medicare Manual provided little to no additional guidance regarding the inclusion or exclusion of claims when conducting the statistical analysis. By contrast, the revised Medicare Manual specifically states:

The universe includes all claim lines that meet the selection criteria. The sampling frame is the listing of sample units, derived from the universe, from which the sample is selected. However, in some cases, the universe may include items that are not utilized in the construction of the sample frame. This can happen for a number of reasons, including but not limited to:

1. Some claims/claim lines are discovered to have been subject to a prior review;
2. The definitions of the sample unit necessitate eliminating some claims/claim lines; or
3. Some claims/claim lines are attributed to sample units for which there was no payment. 

By providing detailed criteria with which contractors should exclude certain claims from the universe or sample frame, the revised Medicare Manual will also provide suppliers another means to argue against the validity of the extrapolation.

Lastly, the revised rules explicitly instruct the auditors to retain an expert statistician when changes occur due to appeals and legal arguments.

As a challenge to an extrapolated overpayment determination works its way through the administrative appeals process, often, a certain number of claims may be reversed from the initial claim determination. When this happens, the statistical extrapolation must be revised, and the extrapolated overpayment amount must be adjusted. This requirement remains unchanged in the revised PIM; however, the Medicare contractors will now be required to consult with a statistical expert in reviewing the methodology and adjusting the extrapolated overpayment amount. 

Between my first article on extrapolation, “CMS Revises and Details Extrapolation Rules,” and this follow-up, you should have a decent understanding of the revised extrapolation rules that became effective Jan. 2, 2019. But my two articles are not exhaustive. Please, Google Change Request 10067 for the full and comprehensive revisions.

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