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Chapter 2c

Creation of New Race-Ethnicity Codes and Socioeconomic Status (SES) Indicators for MEdicare Beneficiaries - Chapter 2c

2. Methods and Data (continued)

2.6 Selection of a Sample of 1.96 Million Medicare Beneficiaries from the EDB

We selected a nationally representative stratified, simple, random sample of traditional fee-for-service Medicare beneficiaries designed to over-sample minorities to create and validate an SES index (discussed in the next section of this report), prepare tabulations (discussed in the following section), and conduct multivariate analyses (discussed in the final section).This sample was initially drawn for analyses performed in the previous task order contract and reported on in the report titled Health Disparities: Measuring Health Care Use and Access for Racial/Ethnic Populations (2005).

We drew the sample from the full 10 segments of the mid-2003 unloaded EDB. To be eligible for inclusion in the sample, beneficiaries must have been enrolled in traditional fee-for-service (FFS) Medicare (Part A, Part B, or both) for the full 12 months of the 2002 calendar year and not have been enrolled in a Group Health Organization at all during the 2002 calendar year. In addition, beneficiaries must have been alive for the full 12 months of calendar year 2002. We set these criteria to allow the maximum opportunity (period of time) for beneficiaries to submit claims documenting their use of preventive and other Medicare covered services.

Table 2.12 presents a distribution of the beneficiaries included on the EDB eligible for the sample by their NEWRACE (their race/ethnicity code resulting from the use of the naming algorithm created by RTI) and by EDBRACE (their race/ethnicity code on the EDB before using the naming algorithm), respectively.

The primary sampling goal at the time this sample was selected was to have sufficient sample size to provide equally accurate and precise estimates of health care utilization for the different racial/ethnic groups. We therefore stratified by race/ethnicity and sampled such that, to the extent possible, the same number of Medicare beneficiaries would be included in the sample in each of the different racial/ethnic groups. This meant that the sample included disproportionately more minorities than their representation in Medicare. The sampling rates based on the NEWRACE code was 11 percent for Black Medicare beneficiaries, 1.2 percent for White, 26 percent for Hispanic, 71 percent for Asian/Pacific Islander, and 100 percent of American Indian/Alaska Native, Other, and Unknown.

Table 2.12 Distribution of Medicare fee-for-service beneficiaries believed eligible for the study sample by NEWRACE and EDBRACE

Race/Ethnicity CategoryFrequency of NEWRACEFrequency of EDBRACE
Non-Hispanic White25,907,88327,091,613
Non-Hispanic Black3,025,3973,087,034
Hispanic2,081,123730,147
Non-Hispanic Asian/Pacific Islander592,010453,950
Non-Hispanic American Indian/Alaska Native121,024122,156
Non-Hispanic Other183,242412,198
Unknown61,56775,148
Total31,972,24631,972,246

Source: EDBRACE is from the Medicare EDB from mid-2003 and NEWRACE is the result of running the algorithm on those same beneficiaries from the Medicare EDB from mid-2003.

These sampling rates produced the sample presented in Table 2.13 according to NEWRACE and EDBRACE.

Table 2.13 Distribution of Medicare fee-for-service beneficiaries selected for the study sample by NEWRACE and EDBRACE

Race/Ethnicity CategoryFrequency of NEWRACEFrequency of EDBRACE
Non-Hispanic White333,334658,279
Non-Hispanic Black333,334350,879
Hispanic545,643191,402
Non-Hispanic Asian/Pacific Islander421,859312,785
Non-Hispanic American Indian/Alaska Native121,024121,496
Non-Hispanic Other183,242299,015
Unknown61,56766,147
Total2,000,0032,000,003

Source: EDBRACE is from the Medicare EDB from mid-2003 and NEWRACE is the result of running the algorithm on those same beneficiaries from the Medicare EDB from mid-2003.

White and Black beneficiaries have the same size sample, while American Indian/Alaska Native, Other, and Unknown have fewer, and Hispanics and Asians/Pacific Islanders have slightly more. As already mentioned above, our sampling goals were to have as close to equal sample for each race/ethnicity as possible in order to provide equally accurate and precise estimates of utilization for each of the racial/ethnic groups. Thus, we sampled 100 percent of the American Indian/Alaska Native, Other, and Unknown beneficiaries and therefore could not get them any closer to the White and Black numbers. In the case of Hispanic and Asian/Pacific Islanders beneficiaries, however, we increased their allocation in the sample slightly because we wanted the estimates to be as close to equally precise across the race/ethnicity categories when the NEWRACE code was used rather than the EDBRACE. (The number of Asian/Pacific Islanders and Hispanics would have dropped whenever the EDBRACE code was used instead of the NEWRACE and so would the precision of the estimates; therefore, we decided to sample more Asian/Pacific Islanders and Hispanics to maintain the precision of the estimates).

After the sample was selected, we cross-referenced it with CMS's denominator file as a final check on eligibility and discovered that slightly less than two percent of the selected sample, spread proportionately across the racial/ethnic groups, did not meet all of our desired sample eligibility criteria – alive and enrolled in fee-for-service Medicare for the entire year. We identified and discarded the ineligibles from the sample and recalculated the weights of the remaining sample to correctly represent the intended population of eligible Medicare fee-for-service beneficiaries. Table 2.14 presents the final number of sampled beneficiaries by NEWRACE and EDBRACE.

Table 2.14 Distribution of final study sample of selected Medicare fee-for-service beneficiaries by NEWRACE and EDBRACE

Race/Ethnicity CategoryFrequency of NEWRACEFrequency of EDBRACE
Non-Hispanic White329,954647,653
Non-Hispanic Black328,246345,559
Hispanic534,196187,920
Non-Hispanic Asian/Pacific Islander415,190308,890
Non-Hispanic American Indian/Alaska Native120,557121,025
Non-Hispanic Other171,032283,603
Unknown60,94665,471
Total1,960,1211,960,121

Source: EDBRACE is from the Medicare EDB from mid-2003 and NEWRACE is the result of running the algorithm on those same beneficiaries from the Medicare EDB from mid-2003.

Table 2.15 contains the distribution of the weighted number of Medicare beneficiaries contained in the EDB who are represented in the sample distributed by the NEWRACE and EDBRACE variables.

Table 2.15 Distribution of weighted study sample of selected Medicare beneficiaries by NEWRACE and EDBRACE

Race/Ethnicity CategoryFrequency of NEWRACEFrequency of EDBRACE
Non-Hispanic White25,645,17826,779,400
Non-Hispanic Black2,979,2173,053,618
Hispanic2,037,463720,664
Non-Hispanic Asian/Pacific Islander582,651449,914
Non-Hispanic American Indian/Alaska Native120,557121,818
Non-Hispanic Other171,032397,030
Unknown60,94674,600
Total31,597,04431,597,044

Source: EDBRACE is from the Medicare EDB from mid-2003 and NEWRACE is the result of running the algorithm on those same beneficiaries from the Medicare EDB from mid-2003.

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2.7 Identifying the Top 10 Metropolitan Statistical Areas (MSAs) for Asian/Pacific Islander and Hispanic Elderly Population

In addition to the tabular investigations to be performed of racial and ethnic disparities in health care utilization by Medicare beneficiaries at the national level, this task was intended to provide additional insight into racial and ethnic disparities in smaller areas with high concentrations of elderly Asians and Hispanics. Rather than target states with large Asian and Hispanic residents, the task called for us to identify metropolitan statistical areas (MSAs) in which there would potentially be large numbers and high concentrations of Asian/Pacific Islander and Hispanic Medicare beneficiaries. The purpose for looking at utilization in selected MSAs was to investigate whether, in areas where members of these minorities were a significant segment of the health care market, there were fewer disparities in services used and greater similarities in health care use to that of non-Hispanic Whites. It is important to keep in mind that in such analyses, the number of Medicare beneficiaries in the sample and the frequency with which the services were used for the MSAs studied had to be adequately large to achieve statistically reliable estimates.

To investigate this issue, we identified the ten MSAs, or the Primary MSAs within Consolidated MSAs, from the 2000 US Census with the largest number of persons 65 years of age and older who identified themselves in the Census as Asian, Native Hawaiian, or Pacific Islanders. The MSAs we identified are listed in Table 2.16 for Asians/Native Hawaiians /Pacific Islanders. We did the same for persons who were identified as Hispanic or Latino. Those MSAs are identified and listed in Table 2.17 for Hispanics/Latinos. The MSAs are listed according to the number of elderly Asian/Native Hawaiians/Pacific Islander and Hispanic/Latino population in each.

When we prepared the tabulations for this report, it became apparent that the two sets of 10 MSAs reduced to a single set of 16, because four MSAs were common to both lists. The MSAs common to both lists are Los Angeles, New York, Chicago, and San Diego.

Table 2.16 Top 10 MSAs for Number of Asian/Native Hawaiian/Pacific Islander Population 65 Years of Age and Older: 2000

Metropolitan Statistical AreaTotal
population:
Total
Total
population:
Asian/NH/PI
Percent of total
population
who are
Asian/NH/PI
Total
population
65+
Asian/NH/PI
population,
65+
Percent of all
65+ persons
who are
Asian/NH/PI
Los Angeles--Long Beach, CA PMSA9,519,3381,164,55312.2%926,673120,81113.0%
Honolulu, HI MSA876,156481,05154.9%117,73785,42972.6%
New York, NY PMSA9,314,235851,4609.1%1,109,82162,8875.7%
San Francisco, CA PMSA1,731,183406,08723.5%227,62853,81423.6%
Oakland, CA PMSA2,392,557411,81917.2%254,86336,26514.2%
San Jose, CA PMSA1,682,585435,86825.9%160,52731,92619.9%
Orange County, CA PMSA2,846,289395,72313.9%280,76330,18110.7%
Chicago, IL PMSA8,272,768384,9324.7%888,50524,9642.8%
San Diego, CA MSA2,813,833263,3639.4%313,75022,5937.2%
Washington, DC--MD--VA--WV PMSA4,923,153332,9196.8%446,28820,7034.6%
Total in 10 MSAs44,372,0975,127,77511.6%4,726,555489,57310.4%

Source: U.S. Census Bureau, Census 2000 Summary File 1 (SF 1) 100-Percent Data, Table P12. Available online at: http://factfinder.census.gov/servlet/DTGeoSearchByListServlet?ds_name=DEC_2000_SF1_U&_lang=en&_ts=164553925612

Table 2.17 Top 10 MSAs for Number of Hispanic/Latino Population 65 Years of Age and Older: 2000

Metropolitan Statistical AreaTotal
population:
Total
Total
population:
Hispanic or
Latino
Percent of total
population
who are
Hispanic or
Latino
Total
population
65+
Asian/NH/PI
population,
65+
Percent of all
65+ population
who are
Hispanic or
Latino
Los Angeles--Long Beach, CA PMSA9,519,3384,242,21344.6%926,673187,44720.2%
Miami, FL PMSA2,253,3621,291,73757.3%300,552184,62561.4%
New York, NY PMSA9,314,2352,339,83625.1%1,109,821146,21913.2%
San Antonio, TX MSA1,592,383816,03751.2%169,74859,48635.0%
Riverside--San Bernardino, CA PMSA3,254,8211,228,96237.8%342,42349,49914.5%
Chicago, IL PMSA8,272,7681,416,58417.1%888,50544,6205.0%
El Paso, TX PMSA679,622531,65478.2%66,07343,21065.4%
Houston, TX, PMSA4,177,6461,248,58629.9%311,21337,96812.2%
San Diego, CA PMSA2,813,833750,96526.7%313,75034,14910.9%
McAllen-Edinburg-Mission, TX MSA2,813,833750,96526.7%313,75034,14910.9%
Total42,447,47114,369,67433.9%4,484,032820,07018.3%

Source: U.S. Census Bureau, Census 2000 Summary File 1 (SF 1) 100-Percent Data, Table P12. Available online at: http://factfinder.census.gov/servlet/DTGeoSearchByListServlet?ds_name=DEC_2000_SF1_U&_lang=en&_ts=164553925612

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Page last reviewed January 2008
Internet Citation: Chapter 2c: Creation of New Race-Ethnicity Codes and Socioeconomic Status (SES) Indicators for MEdicare Beneficiaries - Chapter 2c. January 2008. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/research/findings/final-reports/medicareindicators/medicareindicators2c.html