Who is Caring for the Underserved? A Comparison of Primary Care Physicians and Nonphysician Clinicians in California and Washington

INTRODUCTION

Inequities in access to care mar the landscape of health care in the United States. Many communities lack sufficient numbers of primary care clinicians.¹ In other communities with an ample supply of clinicians, many patients nonetheless have difficulty obtaining needed services because they lack health insurance or have insurance such as Medicaid that many clinicians do not accept.^2,3

One important objective of national health workforce policy is to produce a supply of health professionals that better meets the needs of underserved populations. This objective featured prominently in federal government decisions in the 1960s and 1970s to institute funding of training programs for family physicians, nurse practitioners, and physician assistants under the authority of Title VII and Title VIII.⁴ These federal programs later expanded to also support training in primary care, internal medicine, pediatrics, and certified nurse-midwifery. Evaluation of the distribution of primary care clinicians and their involvement in care of underserved populations is timely in view of recent proposals that would jeopardize further funding of these federal training programs.

Limited research suggests that family physicians, nurse practitioners, and physician assistants are especially likely to practice in rural communities^1,5,6 and might be more likely to care for low-income patients.^7–,⁹ Other studies restricted to analyses of physician distribution have indicated that family physicians are more likely than other primary care physicians to work in rural and underserved communities.^1,10 No study, however, has comprehensively compared the geographic distribution and patient populations of clinicians across the different primary care disciplines.

A contemporary, comprehensive head-to-head study of primary care clinicians is important in view of the changing health care environment. The only comprehensive study of the geographic distribution of nonphysician clinicians was conducted 25 years ago.¹¹ Since that time, the supply of nurse practitioners, physician assistants, and certified nurse-midwives has grown, and many states have liberalized scope of practice regulations for nonphysician clinicians,^12,13 potentially changing the pattern of clinician location. Implementation of Title VII funding of pediatric and internal medicine training programs might also have produced shifts in physician geographic distribution since the time of earlier studies of physician distribution.

We investigated the degree to which clinicians in different primary care disciplines care for underserved populations. We compared the geographic distribution of physician and nonphysician primary care clinicians in California and Washington and examined the proportion of clinicians in each discipline practicing in underserved communities. We also investigated in more detail the patient populations served by a sample of these clinicians working in urban areas of California.

METHODS

RESULTS

DISCUSSION

Our study is the first to directly compare geographic distribution and patient populations among this large a variety of primary care disciplines. We found substantial differences across primary care clinician groups in California and Washington in their degree of involvement with underserved populations as measured by geographic distribution and patients served. In general, a higher proportion of nonphysician primary care clinicians than physicians practiced in underserved areas and cared for large numbers of minority patients and patients who are Medicaid beneficiaries or uninsured. Physician assistants, in particular, had a relatively large proportion of their members practicing in rural communities, in communities with a high proportion of low-income or minority residents, and in HPSAs. Among primary care physicians, family physicians were much more likely than internists, pediatricians, and obstetrician-gynecologists to practice in rural communities and in HPSAs. Our findings are consistent with those of studies from earlier eras and those of more limited scope^1,5–,¹¹.

It is important to note that the actual number of clinicians in a discipline working in underserved areas is a product of both the proportion of the clinicians in the discipline working in an underserved area and the total number of clinicians in the discipline. Although nonphysician clinicians have the greatest relative likelihood of practicing in rural areas and HPSAs, family physicians have the greatest absolute number of clinicians working in HPSAs and rural areas because there are more family physicians overall in each state, and family physicians have a relatively high propensity to practice in these communities.

Our study has several limitations. The nonclinician databases were less complete than the physician databases because the former relied on state surveys rather than a universal profession-administered database. In both types of data sets, some clinicians lacked information on office address. When we compared the ZIP codes of the preferred mailing address and office address for physicians in California who listed both addresses, however, 84% of these physicians had both addresses in the same ZIP code. In addition, our finding that our results did not change when we excluded physicians and nonphysicians with only preferred mailing addresses suggests that our findings are not likely to be biased by possible misassignment of clinicians based on home, rather than work, addresses.

Another potential source of error is item response bias. To the extent that nonphysician clinicians are more likely than physicians to value a professional persona that emphasizes care for underserved populations, they might be more likely to overestimate the proportions of Medicaid, uninsured, and minority patients in their practices. Audits of primary care physician practices, however, have indicated that physician reports are a valid representation of the relative number of Medicaid patients in their practice.¹⁷

Finally, our results might not necessarily be generalizable to other states. For example, physician assistant training programs in California and Washington might place a higher value on care of underserved populations than do training programs in other states.

Why do the professional disciplines studied have different proclivities for caring for underserved populations? Among the leading possible explanations are differences in scope of practice, service mission, and practice opportunities. Among the primary care physician specialties, family medicine has the broadest scope of practice, making family physicians especially well suited for the ecological niche of serving rural communities without the critical population density to support a triumvirate of internists, pediatricians, and obstetrician-gynecologists. Nurse practitioner and physician assistant training programs oriented toward family practice also tend to prepare their graduates for the comprehensive scope of practice required in rural settings.

Family medicine and the professions of nurse practitioner, physician assistant, and certified nurse midwife came of age in the 1960s and 1970s. A mission of caring for the underserved was one of the justifications not only for creating these specialties and professions but also for instituting federal grants for training programs in these disciplines. Some leaders of the new specialty of family medicine characterized the specialty as a counterculture movement in medicine, in part because of a belief that family medicine would care for populations that had largely been overlooked by mainstream medicine.^18,19 Other voices in family medicine cautioned, however, that the specialty might become marginalized by too great an identification with care for disadvantaged populations. In contrast, greater consensus about an emphasis on service to disadvantaged populations existed among leaders in the nurse practitioner, physician assistant, and certified nurse-midwifery professions as these professions became established in the 1960s and 1970s.^4,20 Our results support the view that the nonphysician primary care disciplines have to a large degree fulfilled their espoused mission of caring for underserved populations.

A third possible explanation that might particularly apply to the nonphysician clinicians is constrained opportunities to practice in more advantaged settings. During the formative decades of these professions, a mission of service to needy populations dovetailed with restrictive state practice regulations and a dominant physician profession. These factors limited practice in settings that would pose more direct competition to physicians in communities not suffering from shortages of primary care physicians. The relatively high proportion of nonphysician clinicians working in community clinics illustrates the convergence of these multiple possible factors: interest among nonphysician clinicians in serving vulnerable populations, active recruitment of these generalist clinicians by commu nity health centers, and limited practice alternatives. Our data cannot answer the important question of the degree to which the observed patterns of practice locations represent active choice by nonphysician clinicians as opposed to lack of other practice opportunities. It is possible, however, that as state practice regulations and Medicare payment policies for these clinicians continue to be liberalized, nonphysician clinicians might find greater opportunities to practice in settings that are not focused on care of underserved populations.

Our study has several policy implications. First, the primary care disciplines—family medicine, nurse practitioner, physician assistant, and certified nurse-midwife—that have been particularly dependent on funding from federal training grant programs such as Title VII and VIII are also the primary care disciplines with the greatest proportion of their members caring for underserved populations. Although this association does not prove that these federal grants have directly produced this pattern of service, it does suggest that these training programs in the aggregate have been relatively responsive to the priorities of the federal government for investment in primary care clinician education. It is doubtful that many of these training programs could continue to meet a mission of public service without ongoing support from the federal and state governments.

Second, the continued maldistribution of primary care clinicians suggests that it is appropriate for government to continue to provide incentives to training programs that emphasize production of clinicians for underserved communities. Traditionally, a key incentive has been funding preferences for programs that have a high proportion of graduates working in underserved settings. Our results suggest this funding preference should be continued. Third, policy makers should continue to monitor the geographic distribution and service patterns of primary care clinicians; the dramatic recent changes in the supply of nonphysician clinicians and state practice regulations for these clinicians could affect many of the underlying factors that influence practice location and populations served, potentially resulting in a change with time in patterns of practice location and populations served.

A host of powerful factors, including differences across practice settings in earning potential, lifestyle preferences, clinical infrastructure, and cultural barriers, perpetuate physician maldistribution in the United States.¹ History has shown the fallacy of expecting growth in physician supply to spontaneously ameliorate this maldistribution through a policy of passive diffusion of physicians to underserved communities.⁴ For physicians and nonphysician clinicians alike, achieving a more equitable pattern of service to needy populations will require ongoing, active commitment by policy makers, educational institutions, and the professions to a mission of public service and to implementation of the incentives and support required to promote care to the underserved.