Medicare Current Beneficiary Survey (MCBS)
2012 National Healthcare Quality and Disparities Reports: Detailed Methods Appendix
The Medicare Current Beneficiary Survey (MCBS) is conducted by the Office of Strategic Planning of the Centers for Medicare & Medicaid Services (CMS). It is a continuous, multipurpose survey of a nationally representative sample of the Medicare population, providing information on aged and disabled Medicare beneficiaries living in communities and long-term care facilities. The sample is selected from Medicare enrollment files, and sample persons are interviewed three times per year over a 4-year period. Sample data are collected through computer-assisted personal interviews of the beneficiary or a proxy respondent if the sample person is not available for the interview. Survey questionnaires are tailored to the residence of the sample person—community or long-term care facility. If the sample person moves from one setting to the other during the period covered by an interview, a separate interview is administered for the time spent in each setting. Thus, beneficiaries are followed continuously over time regardless of where they live. Refer to Public Use File Documentation available at the MCBS Web site (http://www.cms.gov) for detailed information.
The primary goal of the survey is to collect comprehensive information on all medical services used by Medicare beneficiaries, sources of payment, health insurance coverage, and socioeconomic and demographic characteristics of the population. These data are used by the Office of Strategic Planning and the Office of the Actuary to support a host of activities related to the administration of the Medicare Program (health insurance for older and disabled people) and the Medicaid Program (Federal grants to States for medical assistance programs). CMS also uses the data to evaluate the Medicare and Medicaid programs and to assess the financial impact of programmatic change on beneficiaries and the Medicare trust fund.
Two public use files (PUFs) are created for each calendar year of data collected in the MCBS: Access to Care (AC) and Cost and Use (CU). The AC data file is designed to provide early release of MCBS data related to Medicare beneficiaries' access to care. Rapid release of access data is achieved by omitting survey-reported utilization and expenditure data. The file contains access to care, satisfaction with care, and usual source of care data, as well as demographic, health insurance, and health status and functioning data. To facilitate analysis, the information collected in the survey is augmented with utilization and expenditure information from Medicare claims data.
The Cost and Use file brings together survey information and Medicare payments made from administrative bill files. Survey-reported data include information on use and costs of health care services, as well as information on supplementary health insurance, living arrangements, income, health status, and physical functioning. The survey also collects information on health services not covered by Medicare, most notably, prescription drugs and long-term facility care. Medicare bill data include use and cost information on inpatient hospitalizations, outpatient hospital care, physician services, home health services, durable medical equipment, skilled nursing home services, hospice services, and other medical services. This combination file can support a much broader range of research and policy analyses on the Medicare population than would be possible using either survey data or administrative bill data alone.
MCBS Table Notes
The 2012 National Healthcare Disparities Report (NHDR) includes a table on osteoporosis screening, using the 2000, 2003, 2006, and 2008 AC files. The table includes female full-year community residents age 65 and over (H_AGE ≥65 and TYPE = "C"). The sample size is 6,672 and the weighted size is 17,671,557 in the 2008 data.
Estimates derived from the MCBS are presented at both an aggregate level and for select subpopulations. Characteristics used to define subpopulations include age, gender, race, ethnicity, poverty status, health insurance coverage, proximity to metropolitan areas, perceived health status, and function limitations.
The MCBS race and ethnicity variables are coded from beneficiary responses to the survey questions, and the categories are recorded as interpreted by the respondents. The variable in the AC file has seven categories: Asian, African American, Native Hawaiian or Pacific Islander, White, American Indian or Alaska Native, other race, and more than one race. For the NHDR tables, the race categories were reordered and "more than one race" and "other" categories were combined as "multiple races/other."
Ethnicity categories in the tables include total Non-Hispanic, all races; Non-Hispanic, White; Non-Hispanic, Black; and Hispanic, all races. The variable was coded based on the source variables HISPORIG and D_RACE2 in AC files. Hispanics include people of Mexican, Puerto Rican, Cuban, Central or South American, or other Spanish culture or origin, regardless of race.
The MCBS AC files do not have the income variable in a dollar amount. For the NHDR AC tables, income was defined based on a category variable, INCOME. The categories are: negative/poor: income $0-$10,000; near poor/low income: $10,001-$20,000; middle income: $20,001-$40,000; and high income: more than $40,000. The near poor/low income category included some records with value "less than $25,000"; and the middle income category included some records with value "$25,000 or more."
Three age categories are included for the NHDR tables on older community residents: 65-74, 75-84, and 85 and over.
Insurance coverage is based on a combination of Medicare and Medicaid administrative data and survey-reported information on public and private insurance. The types of insurance identified include Medicare fee for service, Medicare managed care, Medicaid, private employer sponsored, private individually purchased (Medigap), private health maintenance organization, and other insurance. Summary versions of these variables are used to create four mutually exclusive groups of Medicare beneficiaries by prioritizing insurance coverage hierarchically as follows:
- Group 1 contains everyone who had Medicaid regardless of other coverage.
- Group 2 contains persons in Medicare managed care plans regardless of other coverage.
- Group 3 contains persons with private insurance (Medigap, employer sponsored, or HMO).
- Group 4 contains all remaining beneficiaries, i.e., Medicare fee-for-service beneficiaries who did not have Medicaid or private insurance.
Sample persons are classified as living in a metropolitan or nonmetropolitan area based on their addresses in the Medicare administrative files.
Perceived Health Status
Each sample person in the MCBS is asked to compare his or her general health to other people of the same age. People receiving a community interview answer the question themselves. If a sample person cannot do so, the proxy for that person answers the question. The possible responses to the question include excellent, very good, good, fair, and poor.
Sample persons are identified as having functional limitations through their responses to six sets of questions about activities of daily living (ADLs) and instrumental activities of daily living (IADLs). Sample persons are asked whether they have a health or physical problem that makes it difficult to perform any of the specified activities. If the response is yes, they are recorded as having a limitation in that particular activity. If the response is "doesn't do," they are asked whether it is because of a health or physical problem. Then, if the response to the followup question is "yes," they are recorded as having a limitation in that particular activity.
The ADLs are activities related to personal care; they include bathing or showering, dressing, eating, getting in or out of bed or a chair, walking, and toileting. The IADLs are activities related to independent living; they include using the telephone, doing light housework, doing heavy housework, preparing meals, shopping for personal items, and managing money. Any limitation reported by a sample person may have been temporary or chronic at the time of the interview.
Computation of Statistics and Standard Errors
The proportions in the tables are weighted, and standard errors are included in the tables in order to assess the impact of sampling variability on the accuracy of the estimates. All estimates and standard errors were derived using SUDAAN statistical software, which accounts for the complex survey design of the MCBS. The Z-test was used for subpopulation comparisons.
If a cell has fewer than 30 observations or the relative standard error of the estimate is greater than 0.30, the estimates for that cell are suppressed. This rule is implemented to avoid reporting statistically unreliable estimates of the characteristics of older community residents. Records with missing values of the analytic variables were excluded from all analyses. Records with missing values of demographic variables were excluded from the demographic categories.