Defining Professional Claims for the Purposes of Attribution
Under a narrow definition professional services are care directly rendered by a physician or related provider. This definition therefore excludes pharmacy, facility, and direct medical equipment. Broader definitions might include these services.
For the purpose of attributing episodes to physicians, RAND has utilized a stricter definition. This was primarily because it is difficult to determine which provider ordered a laboratory test or imaging test because ordering physician is inconsistently recorded in Medicare claims data.
Our goal was to use codes in which the delivering physician played a role in evaluating the patient or deciding to choose this procedure. In making this distinction we hoped to eliminate scenarios such as anesthesiologist providing anesthesiology for a surgery, radiologists reading x-rays, or a pathologist reading a PAP smear. In these scenarios, a physician performs a service but they were not the physician who chose to have that test or procedure performed. On the other hand we would like to include tests such as a cardiologist performing a cardiac catheterization, an anesthesiologist placing a pain pump for a person with chronic pain, a pulmonologist placing an arterial line or central venous catheter. In these scenarios it is most typical that the physician most often evaluated the patient before undergoing the procedure and therefore the associated costs should be go into the attribution rule. We are cognizant that no definition is perfect and there will be disagreements on specific scenarios.
We started with all procedures on the 2007 Medicare National Physician Fee Schedule Relative Value File which includes all services (defined via CPT/HCPCS codes) rendered by providers and their subsequent RVU rates for Medicare. We then used the Berenson Eggers Type of Service (BETOS) system which were developed by CMS and assigns each HCPCS code to categories that are clinically relevant. We first took the subset of codes in the following relevant BETOS categories:
- Evaluation & Management
- Except: - - M5A = Specialist - pathology
- Except: P0- = Anesthesia
- I4A = Imaging/procedure
o Except 0152T
- I4B- Imaging/procedure
- Other (includes chiropractic care, delivery of medications, immunizations, vaccines)
- Except: - - - O1A = Ambulance
- Unclassified (Y) (includes items such as shoulder surgery, physician standby services, birth attendance, certain medication delivery)
This would thereby eliminate most imaging, tests, durable medical equipment, Z codes (exceptions, local, undefined codes).
Defining Evaluation & Management Visits
Some attribution rules assign responsibility to the physician that accounted for the largest fraction of Evaluation & Management (E&M) visits for a patient or within episode. Unfortunately there is no consistent definition of what is an E&M visit.
Some researchers (Pham et al. 2007; Bach et al. 2004) using Medicare data have defined E&M visits as:
Berenson-Eggers type of service code of M1A (office visits, new patient), M1B (office visits, established patient), or M6 (consultations), but excluded Healthcare Common Procedure Coding System codes 99381, 99411, 95115, 99391, 95117, 99236, 99262, 99251, 99255, 99261, 99254, G0175, 99253, or 99252.
We believe that this definition was too restrictive for the purposed of attributing episodes, because it excludes inpatient, consultation, or emergency department visits. These visits might not be important for assigning a physician (likely a PCP) to a patient, but these E&M visits are important for attributing a physician to an episode.
Alternative definitions of E&M visits have been created by the American Medical Association's Current Procedural Terminology (CPT) and the Center for Medicare and Medicaid Service's Berenson-Eggers (BETOS) system. CPT's system, while it likely covers most important line items, does not include several important HCPCS codes. We've therefore started with the BETOS system.
Using the BETOS system we first selected all E&M visits in the following BETOS categories:
- - - M1A = Office visits - new
- - - M1B = Office visits - established
- - - M2A = Hospital visit - initial
- - - M2B = Hospital visit - subsequent
- - - M2C = Hospital visit - critical care
- - - M3- = Emergency room visit
- - - M4A = Home visit
- - - M4B = Nursing home visit
- - - M5B = Specialist - psychiatry
- - - M5C = Specialist - ophthalmology
- - - M6- = Consultations
We excluded two E&M BETOS categories M5A (Specialist - pathology) and M5D (Specialist - other). For the purposes of attribution, analyses led by pathologists are not applicable and as of 2003 the data fields used have changed so M5A is not likely applicable in our data. M5D was dropped because these line items don't fit the definition of evaluation and management.
There are 276 HCPCS & CPT codes in these remaining BETOS categories. - Of these we dropped 10:
- 6 Category II CPT or F codes which are used for quality measures and do not indicate a new visit. (0500F, 0502F, 0503F, 1000F, 1001F, 2000F)
- 4 HCPCS codes related to giving shots and delivering drugs which were also dropped in previous definitions.