Klar 2: The great attribution debates: Include specialists or not? Plurality or majority? Retrospective or prospective? Derived or declared?

Ron Klar, MD, MPH

Ron Klar, MD, MPH is a health care consultant with a long history of involvement in federal health care policy and health plan innovation.  He published a recent series of three posts (post 1, post 2, and post 3) regarding the draft rules of the Medicare Shared Savings Program (MSSP) in the Health Affairs Blog, an influential forum for debating health policy issues. In a recent post of my own, I described where I agree with Dr. Klar.  In this post, I’ll describe some areas of disagreement related to the methods of defining the population for which the ACO is to be held accountable.  In two future posts, I’ll cover some additional areas of disagreement.

First, let’s define some terms.

I use the term “care relationship” to describe the data linking patients to providers.  Care relationship information can be “derived” based on other data such as encounter claims records.  Care relationships can be “declared” explicitly when the participants in the relationship – patients and providers – indicate that they intend for the relationship to exist or when they explicitly validate care relationship data that has previously been derived.  Or, care relationship data can be created and maintained through a mixture of derivation and declaration.  Others typically use the terms “attribution,” “assignment,” or “alignment” to describe care relationships, revealing their tendency to think only in terms of derived care relationships.   Derived care relationships can be determined “prospectively,” in advance of an accountability period.  Or, they can be determined “retrospectively,” at the end of an accountability period.

The draft rules for the MSSP proposes to define the population using derived care relationships.  The rules call for accomplishing this derivation by selecting the primary care physician that provided a plurality of the evaluation and management (E&M) encounter claims for a beneficiary, using an assignment process that is partly prospective and partly retrospective.

Dr. Klar proposed to change many aspects of the rules regarding care relationship derivation:

  1. Include specialists, rather than just primary care physicians
  2. The selection should be based on providing a majority (more than half) of the E&M services for a beneficiary, rather than just a plurality (more than anyone else)
  3. The derivation should be purely retrospective

Include specialists or not?

Klar’s proposal to include specialists is based partly on the fact that it will increase the proportion of beneficiaries assigned to an ACO.  Some beneficiaries have visits to specialists, but not visits to PCPs.  Such beneficiaries will only be assigned to an ACO if the assignment includes specialists.  Klar also asserts that including specialists in the assignment will stimulate organizations to “tie” specialists into the ACO.

For both of these same reasons, we originally included specialists in the “attribution” algorithms in the Physician Group Incentive Program (PGIP) at Blue Cross Blue Shield of Michigan (BCBSM).  But, we determined it was necessary to switch to what we called a “pure PCP” algorithm due to unanticipated consequences of including specialists in the attribution. When attribution includes specialists, beneficiaries with expensive conditions requiring specialist care are relatively more likely to be assigned to a physician organization (PO) or ACOs that include specialists, while PO/ACOs that don’t include specialists will tend to have a lower risk population.  Within the PO/ACO, a primary care physician that manages more of the heart failure in her panel of patients will have those patients assigned to her.  Another primary care physician who chooses instead to refer his heart failure cases to higher cost cardiologists will end up with those patients being assigned to the cardiologist.  As a result, the PCP that refers out heart failure management will have a more favorable utilization and cost profile.  These biases make it difficult to interpret performance comparisons when specialists are included in attribution.  I strongly prefer the “pure PCP” attribution approach.

Use plurality or majority?

In the PGIP program, as in the draft rule for the MSSP, we derived care relationships based on a plurality of E&M services, not a majority.  Whether the topic is managed care, patient-centered medical home, organized systems of care, or accountable care organizations, the idea is for providers to take responsibility for the care of a defined population.  Patients that flutter among many PCPs and don’t see any one PCP the majority of the time are still part of the population.  In fact, convincing such patients to have a more stable, exclusive relationship with one physician, or at least one primary care practice unit, should be a key objective of an ACO.  A majority standard would leave more members of the population without a derived care relationship with a PCP.  Therefore, a plurality standard is better than a majority standard.

Prospective or retrospective?

The draft rule for the MSSP proposes an assignment process that is partly prospective and partly retrospective. Many critics of the draft rule have called for a purely prospective derivation, arguing that ACO providers should only be held responsible for the cost and quality of care for patients that they knew about in advance.  But, Dr. Klar went against the crowd, calling for a purely retrospective derivation. He argued that the delay in claims data used for the derivation is too long, resulting in too much inaccuracy in care relationship data due to people switching their actual care relationships during the year.  Based on 25-33% annual turnover in care relationships, 44-55% of beneficiaries assigned before the start of a performance year would not still be assigned after the end of that performance year.  On that point, I agree with Dr. Klar.

But then Dr. Klar went on to provide another argument against any prospective assignment.  He asserted that prospective assignment would create an “undesirable distinction” among Medicare beneficiaries, causing prospectively assigned beneficiaries to be “treated differently” by providers.  He considered such distinctions to be inconsistent with expectations for the traditional Medicare fee-for-service program.  On this point, Dr. Klar has a lot of company.  Many advocates for Medicare beneficiaries are strongly defensive of the unlimited choice of providers currently intrinsic to the traditional Medicare program.  In that spirit, the health reform legislation prohibits restrictions limiting beneficiaries’ ability to  seek care from any participating Medicare provider. This prohibition could be interpreted as implicitly forbidding providers from having care relationship declaration processes where patients document their intention to have a primary care physician relationship, since that would possibly give the impression of “lock-in.”

The underlying debate about the role of the PCP

When I step back from the technical details and look at the bigger picture, it seems to me that Dr. Klar, like many others engaged in discussions about ACOs, seems to have a different conceptualization of the role of PCPs in ACOs than I do.  In proposing the inclusion of specialists in care relationship derivation, and by expressing concern about even giving the impression of fettering beneficiaries’ choice of providers, Klar reveals a conceptualization of an ACO that emphasizes the value of the organization, but does not necessarily emphasize the central role of PCPs.

I feel that a powerful, influential care relationship between a patient and her primary care physician is the main active ingredient in achieving ACO cost savings. In this context, the process of having patients declare or validate their care relationships is an important tool to creating the type of care relationship consistent with the vision of the patient-centered medical home (PCMH). In a PCMH care relationship, the patient understands the roles and responsibilities of the members of the team, and conceptualizes the patient and family as engaged members of that team.  In a strong PCMH-style primary care relationship, the primary care team can influence the patient’s behavior, encouraging adherence to the care plan, and promote effective self-management, involvement in informed medical decision-making, and healthy lifestyle behaviors.  Moreover, in a strong PCMH primary care relationship, the PCP can influence referrals for specialty and facility care, steering the patient toward specialists and facilities that are efficient and prudent. Such a role, when enforced through HMO-style mandatory referral authorization, can seem undesirable from the patient’s perspective, earning the pejorative title “gatekeeper.”  But, in a PCMH and ACO context, the primary care physician is challenged to effectively fulfill the gatekeeper function with one hand tied behind his back.  In an ACO, the patient is not required to seek a mandatory referral authorization from the PCP.  Therefore, to have influence over referral patterns, the PCP is challenged to earn the trust of patients and their families by demonstrating clinical competence and offering excellent service.  They are challenged to exert referral influence in softer ways designed to be satisfying or at least acceptable to the patient.  This influence causes more specialty and facility care to be delivered by more efficient providers.  And, it incentivizes all specialists and facilities to be more efficient.  In my estimation, this form of influence is the strongest active ingredient driving savings in ACOs – stronger than care coordination, stronger than patient-self management support, stronger than avoiding gaps in care through clinical decision support, and stronger than the avoidance of duplication of services through health information exchange.

Of course, there needs to be clear communication to beneficiaries of the voluntary nature of care relationships.  It must be clear that any declared care relationship information maintained by ACOs will not be used to determine shared savings or for any other CMS program administration purposes. But, the worry that ACO providers might implicitly influence patients to have an exclusive primary care relationship with them is not a risk.  In fact, the success of the ACO concept depends on it.

In summary, I’m willing to join Dr. Klar in his contrarian idea of using a purely retrospective care relationship derivation to determine MSSP reward payments.  But, I feel that the care relationship should be “pure PCP,” and the derivation algorithm should cast a wide net with a plurality criteria.  And, MSSP rules should make it clear that ACOs are permitted to create their own processes to track current care relationships, including processes that involve physician and patient declarations of care relationships.




2 thoughts on “Klar 2: The great attribution debates: Include specialists or not? Plurality or majority? Retrospective or prospective? Derived or declared?”

  1. Pingback: Klar 3: Why it is necessary to re-qualify the population to avoid regression-to-the-mean bias in historical comparison groups

  2. Pingback: Klar 4: Why is it important for CMS to Share Claims Data with ACOs?

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