Physician Workforce: Physician Supply Increased in Metropolitan and Nonmetropolitan Areas but Geographic Disparities Persisted
Released: 2003-10-31T00:00:00

Letter

Background

From the 1950s until the early 1970s, concerns about physician shortages prompted measures by the federal and state governments to increase physician supply. Federal and state governments supported the growth in the physician population by providing funds for constructing medical schools and increasing medical school class sizes, offering loans and scholarships to medical students, and paying hospitals through Medicare to subsidize residency training costs. Concurrent with these initiatives, the total physician supply and per-capita supply increased in the United States.

By the 1980s and through the 1990s, however, concerns were raised about the adequacy of the physician supply. A 1981 study by the Graduate Medical Education National Advisory Committee (GMENAC) and a series of reports from 1992 to 1999 by the Council on Graduate Medical Education (COGME) forecast a national physician surplus. COGME based these estimates on its determination that the appropriate target for physician supply ranged from 145 to 185 physicians per 100,000 people. These estimates were predicated in part on the belief that managed care, with its emphasis on preventive care and reliance on primary care gatekeepers exercising tight control over access to specialists, would become a more typical health care delivery model. COGME and others have noted that managed care has not become as dominant as predicted. By 2000, some research concluded that physician supply increased even more than these studies predicted. Some researchers, however, questioned whether there was a national surplus of physicians.

A report from the Institute of Medicine (IOM) describes why studies of the physician workforce vary. According to the IOM report, disagreement about the adequacy of physician supply arises because there is no single accepted approach to estimating physician supply or demand. Varying assumptions related to factors that may affect future supply or demand can lead to different conclusions about the adequacy of future physician supply. Projecting future physician supply depends on the approach used to count physicians, measure their productivity, and estimate the rate of entrance into and exit from the profession. Estimating demand for physicians’ services requires even more assumptions. Demand for physicians’ services can be estimated using current and projected service utilization patterns or by determining an ideal level of care to treat the projected incidence and prevalence of illness among the population. In addition, physician practice patterns, the use of new technology, the supply and role of nonphysician providers, and rates and levels of insurance coverage also affect estimates of the demand for and supply of physicians’ services.

In spite of the difficulty of determining whether the overall number of physicians is indeed the right number, there is little disagreement that physicians have been located disproportionately in metropolitan areas relative to the U.S. population. Geographic disparities in physician supply have persisted even as the national physician supply has increased steadily. Economic factors and professional preferences have all been offered as evidence to explain why physicians, and specialists in particular, locate in metropolitan areas. For example, physicians depend on the availability of hospitals, laboratories, and other technology, and metropolitan areas tend to have more of these facilities and equipment than nonmetropolitan areas. Small nonmetropolitan areas generally lack a large enough population or hospital resources to support a specialty practice, because specialists handle less prevalent but more complicated illnesses and require more specialized support facilities and technology.

To influence overall physician supply and address perceived physician shortages in certain areas, several federal programs fund efforts to address these issues. The bulk of federal dollars to support physician education is through Medicare’s graduate medical education (GME) payments to teaching hospitals, which totaled an estimated $7.8 billion in 2000, the latest year for which data were available. These GME payments are distributed based on the number of physicians being trained and Medicare’s share of patient days in the hospital. Medicare also pays physicians a 10 percent bonus above the usual payment amount for services they provide to beneficiaries in health professional shortage areas (HPSAs). These Medicare Incentive Payments totaled $104 million in 2002.

Programs intended to encourage health professionals to practice in underserved areas and to support the training and education of health professionals are administered by HRSA, within the Department of Health and Human Services (HHS). HRSA programs include the National Health Service Corps (NHSC) and grant and loan support programs for health professions education and training. Most of these programs address three objectives of improving the distribution of health professionals in underserved areas, increasing representation of minorities and individuals from disadvantaged backgrounds in health professions, and increasing the supply of health professionals. They also address other objectives such as improving the quality of education and training. In fiscal year 2001, spending for the NHSC was $70.8 million and spending for health professions education and training programs was $266 million. Funds for the NHSC and for health professions education and training programs support a range of health professions including medicine. See appendix II for more information about program spending or appropriations and program objectives.

National Physician Supply Grew at Twice the Rate of the U.S. Population

The number of physicians in the United States increased about 26 percent, from about 541,000 to about 681,000 from 1991 to 2001. Physician growth was twice that of national population growth during this period. As a result, the total number of physicians per 100,000 people in the United States climbed 12 percent, from 214 in 1991 to 239 in 2001. The number of generalists per 100,000 people increased at about the same rate as the number of specialists per 100,000 people. (See table 1.) The national physician workforce maintained approximately a one-third generalist to two-thirds specialist composition between 1991 and 2001.

Growth in physician supply reduced the number of metropolitan and nonmetropolitan areas with fewer than 100 physicians per 100,000 people and increased the number of areas with greater than 300 physicians per 100,000 people. In 1991, 8 metropolitan areas and 27 statewide nonmetropolitan areas had fewer than 100 physicians per 100,000 people. By 2001, no metropolitan areas and 7 statewide nonmetropolitan areas had fewer than 100 physicians per 100,000 people. Twice as many metropolitan areas and statewide nonmetropolitan areas had at least 300 physicians per 100,000 people in 2001 as in 1991. (See figs. 1 and 2.) In 1991, the 25 percent of areas with the lowest physician supplies per 100,000 people had an average of 106 physicians per 100,000 people. By 2001, the 25 percent of areas with the lowest physician supplies per 100,000 people had an average of 132 physicians per 100,000 people. Similarly, the 25 percent of areas with the highest physician supplies per 100,000 people had an average of 319 physicians in 1991 and 362 physicians in 2001. See appendix III for information on physician supply by state metropolitan and nonmetropolitan areas in 1991 and 2001.

Physician Supply Per 100,000 People Increased in Most Areas but Geographic Disparities Persisted

All 48 statewide nonmetropolitan areas experienced an increase in the number of physicians per 100,000 people from 1991 to 2001 and 301 of 318 metropolitan areas experienced an increase in physicians per 100,000 people. Overall, the nonmetropolitan areas had higher proportional growth in physicians per 100,000 people than the metropolitan areas, but the disparity in the supply of physicians per 100,000 people between the metropolitan and nonmetropolitan areas persisted. Rates of growth in the number of physicians per 100,000 people, the supply of physicians per 100,000 people, and the mix of generalists and specialists among categories of metropolitan and nonmetropolitan counties varied. Among the five county categories we analyzed, nonmetropolitan counties with a large town had the biggest increase in physicians per 100,000 people from 1991 to 2001 and more physicians per 100,000 people than either nonmetropolitan counties without a large town or rural counties, but still fewer than metropolitan counties. Like metropolitan counties, nonmetropolitan counties with large towns had more specialists than generalists, while other nonmetropolitan counties had more generalists than specialists.

Almost All Areas Gained Physicians Per 100,000 People

The 48 statewide nonmetropolitan areas, including those with the lowest supplies of physicians per 100,000 people in 1991, registered gains in physicians per 100,000 people between 1991 and 2001. However, this growth rate was not even across all statewide nonmetropolitan areas and 7 areas remained below 100 physicians per 100,000 people. Five of these 7 statewide nonmetropolitan areas—Iowa, Indiana, Louisiana, Oklahoma, and Texas—that remained below 100 physicians per 100,000 people, had average increases in physicians per 100,000 people that were less than the 23 percent average increase for the nonmetropolitan United States. The remaining 2—statewide nonmetropolitan Alabama and Tennessee—had increases in physicians per 100,000 people that exceeded the national nonmetropolitan area average, but the number of physicians in these areas was so low in 1991 that this growth was not enough to elevate their physician supply above 100 per 100,000 people in 2001.

In the aggregate, the 318 metropolitan areas of the United States experienced an increase in physicians per 100,000 people between 1991 and 2001. However, 17 (5 percent) metropolitan areas experienced declines in the number of physicians per 100,000 people during this period. (See table 2.) In 2001, 11 of these areas had physician supplies per 100,000 people that were below the national average of 239 physicians per 100,000 people. Only 2 individual metropolitan areas, however—the Topeka, Kansas and Enid, Oklahoma MSAs—experienced an actual decrease in their physician populations between 1991 and 2001. While the remaining 15 areas had more physicians in 2001 than in 1991, the population increase for all of them was large enough that they still experienced a decline over that decade in the number of physicians per 100,000 people. Five of these areas had physician population growth in excess of the national average of 26 percent. However, in these areas the higher-than-average growth in physician supply was exceeded by population growth that was also above the national average of 13 percent, resulting in a decline in physicians per 100,000 people.

Statewide Nonmetropolitan Areas Had Greater Proportional

The number of physicians per 100,000 people in nonmetropolitan areas, in which 19 percent of the U.S. population resided in 2001, increased 23 percent from 1991 to 2001. During this same time, the number of physicians per 100,000 people in metropolitan areas, in which 81 percent Increases in Physicians Per of the U.S. population resided in 2001, increased 10 percent. (See table 3.)

The higher growth rate in physicians per 100,000 people in nonmetropolitan areas over the decade did not translate into a reduction in the gap in the supply of physicians per 100,000 people in metropolitan versus nonmetropolitan areas. The disparity in the supply of physicians per 100,000 people between nonmetropolitan and metropolitan areas persisted because physicians continued to disproportionately locate in metropolitan areas. On net, about 17,000 physicians (12 percent of the physician population increase) went to nonmetropolitan areas between 1991 and 2001, while about 123,000 (88 percent of the physician population increase) went to metropolitan areas. The difference in physician supply between metropolitan and nonmetropolitan areas remained relatively unchanged from 1991, when the difference in supply was 143 per 100,000 people, to 2001 when the difference was 145 per 100,000 people.

In nonmetropolitan areas, the number of specialists per 100,000 people increased faster than the number of generalists per 100,000 people. As a result, the generalist and specialist composition shifted from an even mix of generalists and specialists in 1991 to 48 percent generalists and 52 percent specialists in 2001. In metropolitan areas, generalists and specialists per 100,000 people increased at approximately the same rate, shifting the composition less than 1 percent from 36 percent generalists and 64 percent specialists in 1991 to 35 percent generalists and 65 percent specialists in 2001.

Rates of Growth in Physician Supply Differed Among Categories of Nonmetropolitan and Metropolitan Counties

To obtain additional information about physician supply within nonmetropolitan and metropolitan areas, we aggregated county physician and population data into five categories defined by a county’s nonmetropolitan or metropolitan status and the presence and size of a town within the county. All five county categories had an increase in physicians per 100,000 people from 1991 to 2001. (See fig. 3.) But the rates of growth in physician supply per 100,000 people, supply of physicians per 100,000 people, and mix of generalists and specialists varied by county category. While nonmetropolitan counties with a large town (10,000 to 49,999 residents) had the biggest percentage increase in physicians per 100,000 people of all county categories, their supplies per 100,000 people were still less than large and small metropolitan counties’ supplies in 1991 and 2001. Among nonmetropolitan counties, however, those with a large town had more physicians per 100,000 people than those without a large town or rural counties in 1991 and 2001. Like metropolitan counties, nonmetropolitan counties that are more urbanized—those with a large town—had more specialists than generalists per 100,000 people. Less urbanized nonmetropolitan counties—those without a large town—and rural counties had more generalists than specialists per 100,000 people in 1991 and 2001.

Agency Comments

We provided a draft of this report to HRSA for comment. HRSA said that the study supports the conclusion that the disparity in the distribution of physicians in rural and urban areas persists and has narrowed. HRSA also agreed with our assessment of the difficulties and variation associated with determining an appropriate supply for any given geographic area. However, HRSA noted that the report should draw conclusions to make the report more complete.

HRSA also commented that rural citizens are still grossly underserved, noting that physician supply can be a rough measure of access to physician services in a given area and that even in areas with a large number of physicians many people still lack access due to a number of factors. HRSA’s comments are reprinted in appendix IV.

Although we found that a geographic disparity persists, we did not find that the disparity in the distribution between metropolitan and nonmetropolitan areas has narrowed. Physician supply grew faster in nonmetropolitan than metropolitan areas, on a national basis, but this did not reduce the disparity because there are so many physicians in metropolitan areas. As we stated in the draft report that HRSA reviewed, while nonmetropolitan areas experienced higher growth rates in physicians per 100,000 people, the difference in physician supply per 100,000 people remained relatively unchanged from 1991 to 2001.

HRSA noted that physician supply is only one of several factors affecting the accessibility of health care in an area. However, assessing the adequacy of access to physicians was beyond the scope of our work. HRSA also provided technical comments that we incorporated as appropriate.

We are sending copies of this report to the Administrator of the Health Resources Services Administration and other interested parties. We will also provide copies to others upon request. In addition, the report will be available at no charge on the GAO Web site at http://www.gao.gov. If you or your staff have any questions about this report, please call me at (202) 512-7119 or Christine Brudevold at (202) 512-2669. Major contributors to this report were Kathryn Linehan and Ann Tynan.

Appendix I: Scope and Methodology

To conduct this work, we counted active, nonfederal, patient care physicians with a known address, including interns and residents, in the United States. We used individual physician-level data on medical doctors (MD) from the 1991 and 2001 American Medical Association (AMA) Physicians’ Professional Data, also known as the AMA Masterfile and 1991 and 2001 data on doctors of osteopathic medicine (DO) from the American Osteopathic Association (AOA) Masterfile. These data are widely used in studies of physician supply because they are a comprehensive list of U.S. physicians and their characteristics.

To determine physician supply per 100,000 people, we obtained county- level resident population data for 1991 and 2001 from the U.S. Census Bureau Web site. We used data from the Department of Agriculture Web site to determine urban influence codes for each county. For additional information about physician supply in the United States, we reviewed relevant literature and interviewed academic researchers on the topic of the U.S. physician workforce.

To obtain federal program information, we interviewed officials from the Health Resources and Services Administrative (HRSA) and officials at the Centers for Medicare & Medicaid Services (CMS). HRSA officials provided information on the scope and expenditures of health professions training and education programs and the National Health Service Corps. CMS officials provided information on the Medicare Incentive Payments to physicians providing services in health professional shortage areas.

We combined counts of MDs and DOs to determine the total number of physicians in each of our study years. Each physician was counted without adjustment for hours worked. To determine physicians per 100,000 people, we divided the physician population in a given area by the total population in the area in that same year. To count generalists and specialists we used each physician’s specialty information in the AMA and AOA data files to categorize physicians as generalists or specialists. Physicians whose specialty information was listed as family practice, general practice, general internal medicine, and general pediatrics were categorized as generalists. All other physicians with specialty information available were categorized as specialists.

To assign physicians to a geographic area in the United States, we used address information in the AMA and AOA data files. The address information in these files does not specify whether the address refers to the physician’s home, office, or some other location and it is possible that some physicians live and work in different counties. Because of this limitation, we did not analyze the data at the individual county level. We combined multiple, adjacent counties into larger geographic units. We assigned counties to a metropolitan statistical area (MSA), primary metropolitan statistical areas (PMSA), or New England county metropolitan area (NECMA). We grouped data from all areas within a state that were not in a MSA, PMSA, or NECMA into one statewide nonmetropolitan area for each state. We used 2001 MSA, PMSA, and NECMA classifications for the 2001 and 1991 data.

For analysis by county categories, we used urban influence codes, which group metropolitan and nonmetropolitan counties according to the official metropolitan status announced by the Office of Management and Budget in 1993, based on 1990 Census data. Urban influence codes group counties, county equivalents, and independent cities into nine categories.Metropolitan counties are grouped into two categories (1 and 2) by the size of the metropolitan area. Nonmetropolitan counties are grouped into seven groups (3 through 9) by their adjacency to metropolitan areas and the size of their own city. For this analysis of physician supply, we maintained categories 1, 2, and 9 and collapsed the remaining six categories into two, for a total of five categories. This analysis combines codes 3, 5, and 7 into one category (i.e., nonmetropolitan with a large town) and 4, 6, and 8 into one category (i.e., nonmetropolitan without a large town).

Appendix II: HRSA Programs That Address Supply and Distribution of Health Professionals

HRSA administers programs that encourage health professionals to practice in underserved areas and support health professions education and training. The National Health Service Corps and the State Loan Repayment Program, authorized by Title III of the Public Health Service Act, offer scholarships and loan repayments to health professionals in exchange for a commitment to practice in health professional shortage areas. Grant and loan support programs that support health professions education and training, authorized by Title VII of the Public Health Service Act, have diverse objectives. Generally, these programs support education and training for a range of health professions including medicine, chiropractics, dentistry, optometry, pharmacy, physician assistants, allied health, and public health. While most of the Title VII programs address three objectives of improving the distribution of health professionals in underserved areas, increasing representation of minorities and individuals from disadvantaged backgrounds in health professions, and increasing the supply of health professionals, they also address other objectives such as improving the quality of education and training. Table 4 provides information on Title III and Title VII program spending or appropriations and objectives.

Appendix III: Physicians Per 100,000 People by State Metropolitan and Nonmetropolitan Areas, 1991 and 2001

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Health Workforce: Ensuring Adequate Supply and Distribution Remains Challenging. GAO-01-1042T. Washington, D.C.: August 1, 2001.

Nursing Workforce: Emerging Nurse Shortages Due to Multiple Factors. GAO-01-944. Washington, D.C.: July 10, 2001.

Nursing Workforce: Multiple Factors Create Nurse Recruitment and Retention Problems. GAO-01-912T. Washington, D.C.: June 27, 2001.

Nursing Workforce: Recruitment and Retention of Nurses and Nurse Aides Is a Growing Concern. GAO-01-750T. Washington, D.C.: May 17, 2001.

Health Care Access: Programs for Underserved Populations Could Be Improved. GAO/T-HEHS-00-81. Washington, D.C.: March 23, 2000.

Community Health Centers: Adapting to Changing Health Care Environment Key to Continued Success. GAO/HEHS-00-39, Washington, D.C.: March 10, 2000.

Physician Shortage Areas: Medicare Incentive Payments Not an Effective Approach to Improve Access. GAO/HEHS-99-36. Washington, D.C.: February 26, 1999.

Health Care Access: Opportunities to Target Programs and Improve Accountability. GAO/T-HEHS-97-204. Washington, D.C.: September 11, 1997.

Foreign Physicians: Exchange Visitor Program Becoming Major Route to Practicing in U.S. Underserved Areas. GAO/HEHS-97-26. Washington, D.C.: December 30, 1996.

National Health Service Corps: Opportunities to Stretch Scarce Dollars and Improve Provider Placement. GAO/HEHS-96-28. Washington, D.C.: November 24, 1995.

Health Care Shortage Areas: Designations Not a Useful Tool for Directing Resources to the Underserved. GAO/HEHS-95-200. Washington, D.C.: September 8, 1995.

Health Professions Education: Role of Title VII/VIII Programs in Improving Access to Care is Unclear. GAO/HEHS-94-164. Washington, D.C.: July 8, 1994.