as reimbursement for the services performed. The claim line detail (sometimes generally referred to as line-level information) is a set of in-depth information about the specific services performed. For example, a line will contain a beginning and ending date of services, the patient’s diagnoses (represented by diagnosis codes), the services performed (represented by procedure codes), payment amounts for the services, and the identifier of the provider that performed each service. In a SAS dataset, the claim is spread across multiple records with one record per service rendered.
In Chapter 5, we will transform these separate files to contain all claim- and line-level information in a single record. In other words, we will take the file with multiple records per claim and construct arrays on a single record to represent each of the line-items. This maneuver is not something you would do in your own research programming but, as we will discuss, the advantage is that we can work with a structure of claims data sets that can be created using data from any of the three sources. As such, this transformation “levels the playing field” and makes the remainder of the book accessible to a broader audience. In addition, such a structure just happens to be my preferred method of working with claims data because it affords the opportunity to see the entire paid claim in one record! Because such a transformation can consume valuable resources, more advanced readers should determine for themselves the most efficient way to structure their claims data.
Part B Carrier Claims Data
Carrier claims data contain claims information filed by non-institutional providers using the CMS-1500 claim form. When a Medicare beneficiary goes to the doctor for a checkup, the provider electronically submits a bill to Medicare Part B using the ANSI 837 5010 electronic format (or, using the CMS-1500 paper form). The CMS-1500 form contains details like the beneficiary and provider identifiers, dates of service, the procedures performed, and the patient’s medical diagnosis. The submitted claim goes to the provider’s regional Medicare Administrative Contractor (MAC) for adjudication, processing, and payment. The final action Medicare claims are then made available to the research community as the carrier claims data.
In my experience, users most readily associate this file with claims filed by individual physicians like internal medicine specialists or cardiologists. In other words, most users associate the carrier data set with claims filed for services provided in a doctor’s office, like a checkup. However, the carrier data set also includes claims submitted by providers that you may not readily consider, like clinical social workers, chiropractors, ambulances, nurse practitioners, and physician assistants. In addition, the file also includes claims for services performed outside of a doctor’s office, like ambulatory surgical centers, hospital outpatient departments, and hospital emergency departments.
Durable Medical Equipment (DME) Data
The DME file contains information on final action claims submitted by non-institutional DME providers using the CMS-1500 claim form.6 These claims are processed by the provider’s Medicare Administrative Contractor (MAC) for adjudication and payment. The final action Medicare claims are then made available to the research community as the DME claims data. Durable medical equipment includes wheelchairs and walkers, hospital beds, blood glucose monitors and related supplies, canes and crutches, splints, prosthetics, orthotics, respiratory devices like oxygen equipment and related supplies, and dialysis equipment and supplies.
DME is provided to any beneficiary with Part B insurance as long as it is medically necessary. Beneficiaries with Medicare Part B must have the equipment prescribed for use in their home by their doctor or “treating practitioner” (e.g., a physician assistant or nurse practitioner). A long term care facility can qualify as a beneficiary’s home, but equipment is not covered if it is used in a hospital or a skilled nursing facility. For example, the hospital bed in an inpatient facility is included in the facility charge found in the Inpatient claims data.
Outpatient Claims Data
Outpatient claims data contain information on final action claims filed by institutional outpatient providers.7 Most commonly users think of these providers as hospital outpatient departments. However, the data also includes the claims of other types of institutional outpatient providers like ambulatory care surgical centers, outpatient rehabilitation facilities, rural health clinics, and even community mental health centers.
Medicare Part B pays for many of the outpatient services a beneficiary receives in a hospital like the hospital charge for an emergency department service (as we will see below this does not include the doctor’s charge), getting stitches or a cast, lab and X-ray services, outpatient surgery, observation required to determine if a beneficiary should be admitted for inpatient care, and even the administration of drugs if a beneficiary cannot self-administer the drug. For this reason, the claims in the outpatient data are sometimes referred to as “institutional Part B” claims. Looking forward to Chapter 8, we will see this in action when we do not use the outpatient data set when we sum total Part A costs.
A beneficiary is considered an outpatient if the beneficiary’s doctor has not written the beneficiary an order to be admitted as an inpatient. These services are covered under Medicare Part B and are paid using the Outpatient Prospective Payment System (OPPS). The OPPS pays hospitals a predetermined payment rate (the rate differs by geographic region) to provide these services to Medicare beneficiaries.
Inpatient Claims Data
Inpatient claims data contain information on final action claims submitted by long-stay and short-stay inpatient hospitals for the reimbursement of their facility costs.8 These claims are paid through Medicare Part A. Hospitals file claims for these services using the UB-92 form, also known as the CMS-1450 claim, or the electronic 837i format. It is important to make the distinction between facility costs and other costs for services provided in the hospital (again, more on this in the example below). Facility costs include things like room charges and even some drugs provided during a beneficiary’s hospital stay. As we will discuss below, a doctor’s visit or even a surgeon’s services provided in the facility are billed using the CMS-1500 form and are therefore found in the carrier data.
A beneficiary is considered an inpatient starting the day the beneficiary’s doctor formally admits the beneficiary to the hospital. The distinction between inpatient and outpatient status is very important because it influences how Medicare pays for the services received by the beneficiary. For example, as noted in Chapter 2, a beneficiary cannot be admitted to a skilled nursing facility unless the beneficiary has been discharged from a hospital within the last 30 days with an inpatient stay that lasted at least three consecutive days.
Skilled Nursing Facility (SNF) Claims Data
SNF claims data contain information on final action claims filed by SNF providers.9 Like inpatient claims, SNF claims are billed using the CMS-1450 form or the 837i electronic format and paid through Medicare Part A. Skilled nursing facilities may be part of a nursing home or a hospital and provide skilled nursing and rehabilitative care through specialists such as registered nurses, physical therapists, occupational therapists, speech pathologists, and audiologists.
The purpose of this care is to treat, observe, and manage the conditions of beneficiaries leaving the hospital. The goal of skilled nursing care is to improve or maintain the beneficiary’s current condition, as well as assist beneficiaries in maintaining their independence. Examples of skilled care include physical therapy and intravenous injections. Once admitted to a SNF (see the above section for more information on rules governing admission to a SNF), Medicare pays for SNF services for up to 100 days per spell of illness under specific circumstances. A spell of illness ends 60 days after discharge from a SNF, at which time a patient can be admitted to the hospital and then to a SNF for another 100 days.
SNFs are also paid on a perspective payment basis - resource use groups (RUGs). Each of the 66 RUGs has associated nursing and therapy weights that are applied to create daily base payment rates.
Home Health Claims Data
Home health claims data