HERC: Ask an Economist: November 2017
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Ask an Economist: November 2017


Q: How can I identify a patient’s primary care provider?

A: Patients assignments to providers and teams at each health center are recorded in the Primary Care Management Module (PCMM). Researchers can use the PCMM Corporate Data Warehouse (CDW) domain to find information such as such as provider assignment, title, facility, and dates of assignment. Recently, health centers have shifted from PCMM to a new system, the Reengineered Primary Care Management Module (RPCMM). RPCMM was implemented at different dates at different VA health care centers. As a result, the PCMM CDW domain may not include newer assignments recorded only in RPCMM, and RPCMM CDW domain may not contain old assignments recorded in PCMM. HERC researchers have found that combining PCMM and RPCMM to determine a patient’s primary care team provides a more complete picture of provider assignments than either domain alone.

A report available on the CDW SharePoint site, “RPCMM Data Quality Issues” (intranet only), urges researchers to approach the RPCMM domain with caution. The CDW team found considerable variability in uncaptured record changes across sites. Indeed, the HERC team found that both datasets have many missing values for the date that primary care provider assignment ended. In most cases, the was appropriate because the relationship had not ended, but in some cases, it was inappropriately missing because a new provider had been assigned.

HERC researchers found that by combining PCMM and RPCMM, they could more accurately link patients to a primary care provider. The team assumed that when a new primary care provider was assigned, the old relationship ended on the day immediately prior to the new assignment.

Researchers working with the domains should note that both domains include records for care assignments other than primary care. Notable patient-provider relationships recorded in the data are case manager assignments for mental health patients and for returning veterans. It is important to distinguish these, and not regard them as primary care assignments when filling in missing values for the end date for the primary care relationship.

Resources on PCMM and RPCMM can be found on the VIReC CDW Documentation intranet site and the CDW SharePoint site (intranet only).


Q: What is the correlation between CMS and MCA RVUs?

Although they share the same name, Relative Value Units (RVUs) created for the Centers for Medicare and Medicaid Services (CMS) are not the same RVUs used in the VA Managerial Cost Accounting (MCA) system.


MCA is an activity-based costing system. Activity-based costing combines activity reports, financial data, workload, and intermediate products used in encounters and hospitals stays (Azoulay 2007). These cost estimates are regarded as a more accurate measure of resource use than cost-adjusted charges (Ross 2004; Udpa 2006). RVUs are essential part of MCA and other activity-based costing systems.

MCA RVUs are used to find the cost of intermediate products, specific health care services such as a cholesterol test, a chest x-ray, or a 20-minute clinic visit. MCA tracks the cost of each department and the intermediate products it produces. Each intermediate product has an RVU. The total cost of the department is divided by number of RVUs it produces, giving the cost per RVU, so that the cost of each intermediate product can be found. The cost of a hospital stay or outpatient visits is found by adding together the cost of all the intermediate products used in that stay (or visit).

MCA tracks each type of cost separately (e.g., labor, supplies, management overhead, contract services, and as many as 13 different cost types). Each type of cost has its own set of RVUs. MCA has a standard set of RVUs, but these may be tailored to reflect the specifics of the cost of production at each medical center or department within the medical center. The result is an estimate of costs based on the cost of the department and the intermediate products it produces. MCA cost estimates thus reflect the variations in cost that result from differences in staff and supply costs, efficiency, and the mix of intermediate products used in providing care. The resulting cost estimate reflects resources used in providing care, providing researchers with the opportunity to study variations in cost. For example, HERC researchers have used MCA to find the difference cost that result from different techniques for Coronary Artery Bypass Graft (CABG) surgery.

While the MCA estimates can be highly accurate, the method has the potential for occasional errors. Incorrect mapping of costs and products can distribute the cost of a department to the wrong products or to too few products. MCA has worked over the years to develop auditing and cleaning systems, but researchers should verify MCA cost data. MCA National Data Extracts are available at CDW. Record layouts, metadata, and the Technical Guide are available on the MCA Office website (intranet only).


The RVUs developed for the Centers for Medicare and Medicaid Services (CMS) are used to calculate payments to providers. These RVUs do not represent cost, but were designed to compensate providers based on time, mental effort, technical skill, judgement, and stress. Services are characterized by Current Procedure and Terminology (CPT) code, and separate RVUs are created for physician work, practice expense, and malpractice expense. If the researcher knows the CPT coding of a service, CMS RVUs can be used to estimate the Medicare reimbursement. Medicare reimbursement is sometimes used as a surrogate for costs; it is used that way in the HERC outpatient average cost datasets.

There are limitations with the CMS RVU approach. Notably, the source of CMS RVUs, the Resource Based Relative Value System (RBRVS), was not designed to reflect the actual costs of care, but to set reimbursement as part of a public process that includes comment and input from medical specialty organizations. Critics of the RBRVS reimbursement system say that it is fundamentally flawed because of its reliance on CPT codes to represent provider services. This criticism holds that the CPT coding system can distinguish greater complexity for procedures but not for evaluation and management services (Kumetz and Goodson 2013). MCA does not use RBRVS RVUs, but instead bases its relative values on measures of resource use, such are minutes of time in the operating room or length of the clinic visit.

More information about the different costing methods are available on the HERC website.

Given that MCA and CMS RVUs are different entities, the correlation between CMS and MCA is an empirical question. HERC creates the HERC average cost data using RVUs from CMS and other sources which researchers could use to test the correlation. Studies by Chapko et al (2008) and Phibbs and Schmit (2007) indicate that the datasets are highly correlated.




Azoulay A, Doris NM, Filion KB, Caron J, Pilote L, Eisenberg MJ. The use of the transition cost accounting system in health services research. Cost Eff Resour Alloc. 2007;5:11.

Chapko M, Liu C, Perkins M, et al. Equivalence of two healthcare costing methods: bottom-up and top-down. Health Econ (2008); 18(10):1188-201.

Kumetz E, Goodson JD. The undervaluation of evaluation and management professional services: the lasting impact of current procedural terminology code deficiencies on physician payment. Chest (2013); 144(3):740-745.

Phibbs CS, Schmitt SK. A Comparison of Outpatient Costs from the FY 2001 HERC and DSS National Data Extract Datasets. Technical Report 14. Menlo Park CA. VA Palo Alto, Health Economics Resource Center; 2007.

Ross TK. Analyzing health care operations using ABC. J Health Care Finance. Spring 2004;30(3):1-20.

Udpa S. Activity-based costing for hospitals. Health Care Manage Rev. Summer 1996;21(3):83-96