The missing variable

The effect of physician replacements on health care spending

The United States spends more on health care than comparable nations, with a spending gap that has markedly increased over the past 40 years.1 However, this additional spending has not translated into better health outcomes for Americans, with the United States lagging behind similar nations.2 Although health policy experts and economists have written volumes analyzing the deficit between US spending and health quality measures, 1 variable is always missing: the replacement of physicians by nonphysician practitioners.

Fewer physicians, more nonphysician practitioners

The United States has fewer practicing physicians per capita than most developed nations do, ranking 24th out of 28 countries with just 2.56 physicians per 1000 people. The only countries ranking worse than the United States are Canada (2.46 physicians per 1000), Poland (2.24), Mexico (2.17), and Korea (2.16). For contrast, the top physician ratios occur in Austria (4.99), Norway (4.31), Sweden (4.13), Germany (4.04), Switzerland (4.04), Italy (3.81), and Spain (3.69).3

Not only does the United States not have as many physicians compared with other similar nations, but it is failing to keep up in production of new doctors. The United States ranks 30th out of 35 industrialized countries in producing medical school graduates, graduating only 7.26 new doctors per 100,000 population in 2013, compared with countries like Ireland (20.13), Denmark (18.38), Australia (15.44), and Austria (14.85).4

Although the United States has increased the number of medical schools by 28% since 2003,5 residency slots—the final required stage of physician training—have remained flat due to a cap in payment support from the government that has been frozen place 1997.6 Although experts have decried a physician shortage for years, legislative action has failed to increase the residency slots required for physician licensure.

Rather than training more physicians, US health policy has instead incentivized the training and use of nonphysician practitioners. Although the US lags behind other countries in number of physicians, it leads the world in nonphysician practitioners, with 40.5 nurse practitioners and 40 physician assistants per 100,000 population.7

Expansion of nonphysician roles

Originally created in 1965 by physicians, the nurse practitioner and physician assistant professions were designed to bring primary medical care to underserved areas. However, over the past 40 years, these practitioners have increasingly assumed roles traditionally filled by physicians. Beginning in the 1970s, health care policy incentivized the growth of both professions, funding training programs and mandating the hiring of nonphysician practitioners in federally funded rural health clinics. By 1987, the federal government had spent $100 million on nurse practitioner training programs. In 2010, the Affordable Care Act further expanded the role of nurse practitioners, creating nurse-led clinics. By 2020, nearly half the states in the country had granted nurse practitioners the right to practice independently without physician supervision, with North Dakota recently becoming the first state to grant physician assistants the same privilege.

What impact has this physician replacement had on patient health and cost? We simply do not know. Although research has shown that nonphysician practitioners can provide safe and effective care when treating low-risk patients and working under physician supervision or following physician-created protocols,8 quality studies have not been conducted to evaluate care provided by nonphysicians practicing independently. Although many states have granted nurse practitioners the legislative authority to practice medicine for years, studies on patient outcomes in these “full-practice authority” states are glaringly absent.

Effect on health care costs

In addition, evidence exists that the rapid growth of nonphysician practitioners over the past 40 years may be a factor in the rise in healthcare spending. Studies have shown that nurse practitioners and physician assistants may increase health care costs because of more utilization of health care resources9; longer consultations and more follow-ups10; increased clinical staff time; increased ordering of laboratory11 and radiology tests12; unnecessary skin biopsies13; more prescription medications,14 including unnecessary antibiotics, psychotropic medications, and opioids; and poorer quality of referrals to specialists.15

These additional tests, procedures, and referrals can add up. In 2013, the Institute of Medicine estimated that “unnecessary services” added $210 billion to health care spending in the United States, making it the single biggest contributor to waste.16 Unfortunately, additional health care utilization can also result in large profits for corporations and private equity firms, which have been particularly quick to replace physicians with nonphysician practitioners. Patients often do not have a choice in who provides their care when they visit these facilities.

Can increased expenses be offset by lower salaries for nonphysician practitioners? Probably not. One analysis in the United Kingdom found that employing a nurse practitioner is likely to cost as much or more than a primary care physician.17 Although in the past nonphysician salaries were significantly lower than those of physicians, the pay difference has markedly narrowed, with nonphysicians now advocating for “pay parity”—to be paid the same as their physician counterparts. The state of Oregon already requires that insurance companies pay nurse practitioners and physician assistants the same rates as physicians.18

It is time for health policy experts—and the public—to question whether replacing physicians with nonphysician practitioners is healthy for the state of the nation.


1. Kamal R, Ramirez G, Cox C. How does health spending in the U.S. compare to other countries? Peterson-KFF Health System Tracker. December 23, 2020. Accessed August 8, 2021. https://www.

2. How does the U.S. healthcare system compare to other countries? Peter G. Peterson Foundation. July 14, 2020. Accessed August 8, 2020.

3. Health care resources: physicians – overall. Organisation for Economic Co-Operation and Development. Accessed August 8, 2021. https://stats.

4. Organisation for Economic Co-Operation and Development (OECD). OECD.Stat database search engine. Accessed August 8, 2021. https://

5. Association of American Medical Colleges. Results of the 2017 medical school enrollment survey. May 2018. Accessed August 8, 2021.

6. The role of GME funding in addressing the physician shortage. Association of American Medical Colleges. Accessed August 8, 2021.

7. National Commission on Certification of Physician Assistants. 2018 statistical profile of certified physician assistants. 2019. Accessed August 8, 2021. files/2018StatisticalProfileofCertifiedPhysicianAssistants.pdf

8. Laurant M, van der Biezen M, Wijers N, Watananirun K, Kontopantelis E, van Vught AJAH. Nurses as substitutes for doctors in primary care. July 16, 2018. Accessed August 8, 2021. CD001271/EPOC_nurses-substitutes-doctors-primary-care

9. Hemani A, Rastegar DA, Hill C, al-Ibrahim MS. A comparison of resource utilization in nurse practitioners and physicians. Eff Clin Pract. 1999;2(6):258-265.

10. Venning P, Durie A, Roland M, Roberts C, Leese B. Randomised controlled trial comparing cost effectiveness of general practitioners and nurse practitioners in primary care. BMJ. 2000;320(7241):1048- 1053. doi:10.1136/bmj.320.7241.1048

11. Flynn BC. The effectiveness of nurse clinicians’ service delivery.Am J Public Health. 1974;64(6):604-611. doi:10.2105/ajph.64.6.604

12. Hughes DR, Jiang M, Duszak R Jr. A comparison of diagnostic imaging ordering patterns between advanced practice clinicians and primary care physicians following office-based evaluation and management visits. JAMA Intern Med. 2015;175(1):101-107. doi:10.1001/ jamainternmed.2014.6349

13. Jalian HR, Avram MM. Mid-level practitioners in dermatology: a need for further study and oversight. JAMA Dermatol. 2014;150(11):1149-1151. doi: 10.1001/jamadermatol.2014.1922.

14. Muench U, Perloff J, Thomas CP, Buerhaus PI. Prescribing practices by nurse practitioners and primary care physicians: a descriptive analysis of medicare beneficiaries. J Nurs Regul. 2017;8(1):21-30. doi:10.1016/S2155-8256(17)30071-6

15. Lohr RH, West CP, Beliveau M, et al. Comparison of the quality of patient referrals from physicians, physician assistants, and nurse practitioners. Mayo Clin Proc. 2013;88(11):1266-1271. doi:10.1016/j. mayocp.2013.08.013

16. Committee on the Learning Health Care System in America; Institute of Medicine. A Continuously Learning Health Care System. In: Smith M, Saunders R, Stuckhardt L, McGinnis JM, eds. Best Care at Lower Cost: The Path to Continuously Learning Health Care in America. National Academies Press; 2013:chap 5. Accessed August 8, 2020. https://www.

17. Hollinghurst S, Horrocks S, Anderson E, Salisbury C. Comparing the cost of nurse practitioners and GPs in primary care: modelling economic data from randomised trials. Br J Gen Pract. 2006;56(528):530-535.

18. NP payment parity bill signed into law. Nurse Practitioners of Oregon. Accessed August 8, 2021. https://www.