not appear in Medicare administrative data or, at the least, may require searching multiple files. For example, Part D prescription drug data contains information for prescription drug fills. Prescription drugs administered during a hospital stay may not appear in the claims data at all. Additionally, services paid for by Medicare Part C may not appear in the administrative claims files because they are paid for by managed care providers.12
• Medicare pays for some services (e.g., home health agencies, hospice, hospital outpatient, skilled nursing, or acute inpatient hospitals) using what are called prospective payment systems (PPS). In very simple terms, a PPS reimburses providers using a fixed amount derived from a predetermined classification system.13 We will discuss payment systems more in Chapter 8.
• As a social insurance program, Medicare coverage is provided regardless of medical history. Therefore, if you are used to working with commercial healthcare claims data, you will likely notice some unique characteristics of the Medicare population, such as a higher prevalence of chronic conditions.
• The administrative data we use for research purposes are updated on a regular basis, but only with claims that have been received and adjudicated and deemed final action. As such, the files we use at any given time do not contain all final action claims submitted and paid up to the date of extraction of the data. It is common practice to wait at least three months for paid claims to appear in the claims files maintained by CMS. For example, a request for claims for the full calendar year 2014 is best made on or after April 1, 2015.
• Depending on what you are studying, care must be taken to determine the correct composition of your study population. For instance, our example research project will study only those beneficiaries continuously enrolled in fee-for-service Medicare during a defined timeframe. Other studies may wish to focus on beneficiaries entitled to Medicare based on being disabled. We will see in Chapter 6 that we can use enrollment data to determine a beneficiary’s reason for entitlement and define our study population.
Chapter Summary
In this chapter, we set a foundation for programming with SAS and Medicare administrative data by examining the following:
• Understanding the Medicare program and the particulars of Medicare coverage is absolutely essential to successfully programming with Medicare administrative data.
• Medicare is a social insurance program that provides beneficiaries with an array of health insurance coverage, regardless of income or medical history.
• The majority of Medicare beneficiaries are eligible for Medicare insurance because they are aged 65 and over. However, Medicare also insures beneficiaries who are permanently disabled (receiving Social Security Disability Insurance or SSDI), have ESRD, or have ALS.
• Medicare benefits are divided and defined in four parts: Part A (Hospital Insurance), Part B (Supplemental Medical Insurance), Part C (Medicare Advantage), and Part D (outpatient prescription drug coverage). Each Part covers a different type of care or set of services. These Parts are a way of describing coverage, but also a way of organizing the way we think about the administrative data files we will use throughout this book.
• Like other health insurance plans, Medicare does not cover every possible medical service or procedure.
• The primary purpose of Medicare payment systems is not to create data for research, but to adjudicate and pay claims. This fact has implications for using the administrative data files and means that the user must understand the Medicare program.
1 See: www.resdac.org, www.cms.gov, www.medicare.gov, and www.kff.org.
2 Medicare eligibility is more complicated than the simple presentation above. For more information, see federal resources such as http://www.medicare.gov/publications/pubs/pdf/11306.pdf.
3 See the Medicare timeline at http://kff.org/medicare/video/the-story-of-medicare-a-timeline/.
4 Information provided in this paragraph, and more, can be found throughout the KFF Medicare Primer (April 2010) (http://www.kff.org/medicare/7615.cfm).
5 Although we will not discuss Medicaid in this text, some beneficiaries are eligible for and enrolled in both Medicare and Medicaid. These beneficiaries are referred to as Medicare-Medicaid Enrollees, or MMEs.
6 Your Medicare Benefits can be found at http://www.medicare.gov/publications/pubs/pdf/10116.pdf.
7 Medicare and You can be found at http://www.medicare.gov/publications/pubs/pdf/10050.pdf.
8 We mention below that medication provided in institutional settings (like during a hospital stay) may be covered by Medicare, but does not necessarily appear in the administrative claims data files used for research purposes.
9 The reader should check the Medicare benefits schedule for the most up-to-date information.
10 See CMS’s Medicare Coverage of Skilled Nursing Facility Care booklet, page 17, available at http://www.medicare.gov/Pubs/pdf/10153.pdf.
11 Medicare claim forms include the CMS-1500 for physician or professional billing and the UB-04 (also known as the CMS-1450) for institutional or technical billing.
12 For more information, see ResDAC’s article at http://www.resdac.org/resconnect/articles/114.
13 Source: CMS’s Prospective Payment Systems-General Information website available at https://www.cms.gov/ProspMedicareFeeSvcPmtGen/.
Chapter 3: An Introduction to Medicare Data
