Loh, Lawrence C. MD, MPH; Peik, Samuel M. MD, MPH
Physician interest in public health and preventive medicine has been growing worldwide, driven in part by unsustainable levels of health care spending, rising rates of chronic disease, global pandemic diseases and disasters, and a resurgence of previously controlled, vaccine-preventable diseases. Although this interest may appear novel, prevention has been described, at least conceptually, since at least 400 B.C.E. when Hippocrates mused that “protecting and developing health must rank even above that of restoring it when it is impaired.”1 Similarly, dietary restrictions described in ancient Judeo-Christian texts represented some the earliest preventive measures taken by the community to prevent disease.2 One such example includes the prohibition on eating animals that died prior to slaughter, a possible indicator of disease.3
An early call to incorporate public health and preventive medicine into modern medical training arose in Abraham Flexner’s4 1910 report, which clearly states: “The physician’s function is fast becoming social and preventive, rather than individual and curative. Upon him society relies to ascertain, and through measures essentially educational to enforce, the conditions that prevent disease and make positively for physical and moral well-being.” Recently, a group of investigators reviewed Flexner’s public health principles,5 and although they highlighted the progress made a century on toward improving the health of the population, they also remained cautious that medical training continues to be overwhelmingly clinical. These authors advocated greater incorporation of public health into medical training because such training would allow future physicians to develop competencies in biostatistics and epidemiology, to cultivate a better understanding of “their roles in the broader health system,” and to learn to “effectively address issues at the population level … by thinking upstream.”5
The approval of the first public health residency programs in the United States in 19516 signaled the birth of public health and preventive medicine as a medical specialty. Such formal, accredited residency programs now form the cornerstone of public health physician training in some countries, such as the United States7 and Canada.8 In other countries, however, no formal clinical training programs exist9; in such places, physicians often self-select public health practice based on their professional interests in policy, research, or program planning, and only occasionally do physicians receive formal training through an educational program such as a master of public health (MPH) degree.
To our knowledge, no existing literature has compared the state of formal public health specialty training in different countries. In this article, we examine the similarities and differences in public health and preventive medicine residency training in Canada and the United States. We consider specific aspects: the definition and scope of the specialty, oversight and location of training programs, residency length and requirements, residency funding, availability of residency positions, specialty certification, and roles of specialists. Our resulting analysis and synthesis aims to support educators and faculty in both countries in their efforts to provide relevant, high-quality training programs while developing transborder collaborations.
Public Health and Preventive Medicine Residency Training in Canada
Definition and scope of specialty
In Canada, the specialty “concerned with the health of populations”10 is now known as public health and preventive medicine (PHPM); it was known as community medicine until 2011.11 The name change is the result of a bid to better reflect the work of PHPM specialists who work in public health fields safeguarding the health of populations. General PHPM specialists are experts with population health knowledge (i.e., an intimate familiarity with the population they are tasked with serving) and skills in biostatistics and epidemiology, environmental health, social and behavioral sciences, health program planning and policy, management, health economics, and relevant biological sciences. These specialists collaborate with one another and other professionals, leading the effort to maintain and improve the health and well-being of the communities they serve. PHPM specialists assess the health needs of the population using tools such as research, surveillance, and population health assessments. These various methods provide data which guide efforts to prevent disease by protecting and promoting community health. Such strategies form the basis of publicly delivered programs; examples include maternal–child health initiatives or harm-reduction measures.10
Oversight and location of specialty training
The Royal College of Physicians and Surgeons of Canada (RCPSC) provides oversight for the PHPM specialty as well as for 62 other specialty and subspecialty medical disciplines in Canada.12 Additionally, the RCPSC defines the roles of the PHPM specialist, and the roles, in turn, form the basis for postgraduate training in the specialty. The RCPSC Office of Education sets standards for all postgraduate medical education, accredits residency programs, assesses applicants’ eligibility for certification, and conducts certifying examinations.12
Nuanced differences in residency program accreditation requirements have resulted in divergent PHPM training philosophies between Canada and the United States. Firstly, unlike in the United States, transitional years and rotating internships ended in Canada in 1990. Instead, Canadian medical students enter residency training directly upon graduation.13 Secondly, Canadian residency programs are always associated with an accredited academic university center14; this formal relationship facilitates collaborations and linkages among the residency training programs associated with a single academic center.
Residency length and structure
The duration of residency training in Canada varies depending on specialty: two years for family medicine, four years for general internal medicine and general pediatrics, and five or six years for many of the other specialty and subspecialty training programs.
Canadian PHPM residency programs are thus five-year direct-entry programs. To a very limited extent, residents may transfer laterally from another residency program within the same academic center. This sort of transfer provides a second potential entry route into PHPM. However, this entry route is relatively uncommon, and credit for previous training is determined on a case-by-case basis.
The training requirements for Canadian PHPM programs specify successful completion of at least one year of each of the following: clinical training, academic work, and field-based PHPM placements/rotations.10 The additional two years of required training are more flexible and may include up to one additional year of clinical training and any combination of academic or field-based training. The typical, but by no means universal, sequence for PHPM training in Canada is as follows (see also below): 2 clinical years, leading to certification as a family physician; 12 to 18 months of graduate training (i.e., academic work), commonly leading to an MPH (or equivalent) degree; and 18 to 24 months of PHPM practicum rotations.10
Clinical training. As mentioned, most trainees complete all of their clinical training prior to beginning their academic and field-based work.
PHPM and family medicine. Because of the substantial overlap between primary care and preventive medicine, many Canadian PHPM programs encourage residents to pursue their family medicine certification while they are completing their PHPM training requirements. Certification in family medicine (from the College of Family Physicians of Canada) requires two years of clinical training in an accredited program15; thus, PHPM residents can fulfill the clinical requirements for family medicine certification during their PHPM residency by completing both the required and the optional year of clinical training within a family medicine residency program without prolonging the five-year residency pathway.15
PHPM and other specialties. Whereas other specialty residency programs may have public health relevance, the direct-entry nature of Canadian residency training makes the incorporation of non-family-medicine specialties within PHPM residency programs difficult. Such combinations (e.g., pediatrics or internal medicine with PHPM) are more historic, dating back to the era of rotating internships, when PHPM was a further subspecialty certification instead of a direct-entry program.
In programs that provide the option, most PHPM residents will complete two back-to-back years of family medicine clinical training, but this is not compulsory. A small minority of residents choose to meet the minimal requirement by completing only the first year of clinical training in family medicine, using the extra year instead for further academic and/or field-based training. On the converse, most Canadian PHPM programs allow family medicine residents to complete a third clinical year focused on enhanced skills (e.g., addiction medicine, women’s health, emergency medicine);15 some PHPM residents have taken leave from the traditional five-year program to pursue such opportunities.
Postclinical training. On completion of clinical training, PHPM residents complete the minimum of one year of graduate public health training (i.e., academic work), most commonly obtaining an MPH degree or equivalent. Entering residents with acceptable previous graduate qualifications receive one year’s credit and can thereby shorten their graduate degree program, leaving 18 to 24 months for completing field-based rotations in PHPM. Other PHPM residents use this additional time either to complete an alternative graduate program (e.g., master of business administration, master of education) or to begin working toward a doctorate of philosophy (PhD) degree.
In the final phase, after finishing their clinical training and academic work, residents are required to complete a minimum of 12 months of field-based placements at accredited program sites. Most programs, however, extend this period to two years in total. Common areas of focus for these placements include communicable disease control, environmental health, program planning, chronic disease, policy, and senior management. Programs have flexibility in specifying obligatory rotations, designing these to provide a comprehensive public health practice experience.
Completion of the five-year program permits a resident to apply to sit for the certifying examinations, which, if successfully completed, grants the title of PHPM specialist. This title provides PHPM practitioners with another qualification or credential in addition to other credentials earned during residency training, commonly (as described) family medicine certification and an MPH degree.
Residents in Canada are funded, regardless of their specialty, through university central payroll offices16 which receive funds from provincial ministries of health. Salaries increase at a negotiated rate according to year of postgraduate year training level, and no national formula for funding exists.
Availability of residency positions
In 2010, approximately 131 residents enrolled in PHPM training programs in Canada17 across 14 residency programs (10 Anglophone [i.e., English speaking] and 4 Francophone [i.e., French speaking]).18 In the 2009–2010 match, 21 first-round positions were available to Canadian medical graduates (CMGs), and 5 first-round positions were available to international medical graduates (IMGs).19 Of these, 15 (71%) of the CMG positions and all 5 of the IMG positions were successfully filled.
An applicant for PHPM certification must be either a graduate of an accredited Canadian or U.S. medical school20 or a graduate of a non-Canadian or U.S. medical school who has proof of having passed a major licensing exam, such as the Medical Council of Canada Qualifying Examination Parts I and II. Once verified, applicants must then pass both the written and oral components of the PHPM RCPSC examination in order to obtain specialty certification as a Fellow of the RCPSC in Public Health and Preventive Medicine.
Maintenance of certification (MOC) allows specialists to renew their fellowship status and may also be a condition of licensure in some provinces. As such, PHPM specialists must accumulate continuing professional development credits through completion of activities such as reading journal articles, completing personal learning projects, or attending conferences.21 Specialists must earn 40 credits per year and 400 credits per five-year cycle. There is no limit on most activities, except for self-reported journal review, which is limited to 100 credits per five-year cycle. At present, there is no required periodic examination to maintain certification.
Roles of specialists
The RCPSC objectives of training10 describe PHPM specialists as physicians who are involved in
the practice of public health at a local, regional, national or international level; the planning and administration of health services, whether in institutions or in government; community-oriented clinical practice with an emphasis on health promotion and disease prevention; the assessment and control of occupational and environmental health problems; teaching and research.
Family-medicine-certified PHPM specialists may also practice clinical medicine, serving as family physicians or focusing on groups of patients relevant to public health (inner-city populations, immigrants/refugees, those suffering from addiction, women, etc.). PHPM specialists serve as physician leaders who use both public policy and the application of health programs to address a broad range of community health issues. Their work can range from local-level control of communicable disease outbreaks and environmental hazards to national research or advocacy on the wider social determinants of health.10
Public Health and Preventive Medicine Residency Training in the United States
Definition and scope of specialty
In the United States, preventive medicine (PM) is the medical specialty that focuses on the health of individuals, communities, and defined populations. PM specialists receive training in the core competencies of biostatistics, epidemiology, environmental and occupational medicine, health services, management of health care organizations, research, and clinical prevention.22 Additional essential knowledge includes an understanding of social and behavioral health, communication, health policy, public health law and ethics, and global health.23
PM includes three specialty areas: aerospace medicine (AM), occupational medicine (OM), and public health and general preventive medicine (PH/GPM). It also includes two subspecialty areas: undersea and hyperbaric medicine and medical toxicology.22 Additionally, the American Board of Medical Specialties (ABMS) recently approved a new subspecialty area: clinical informatics.24,25 The general term “preventive medicine” is often unofficially used to refer to the specialty of PH/GPM. In this article, we use the term “preventive medicine” (or PM) as officially defined (i.e., to encompass AM, OM, and PH/GPM).
Oversight and location of specialty training
In contrast to Canada, the United States has two regulatory bodies that oversee training and certification requirements. The Accreditation Council for Graduate Medical Education (ACGME) sets the standards for, evaluates, and accredits residency programs.26 The American Board of Preventive Medicine (ABPM) oversees the board certification of PM physicians; since 1948, PM has been 1 of the now 24 primary specialties recognized by the ABMS.22,27 A major difference between PM programs in the United States and those in Canada is that, in the former, PM residency programs are affiliated with a variety of sponsoring institutions: medical schools, schools of public health, hospitals, governmental or military institutions, or public health departments.
Before entering a residency training program, prospective PM residents must meet the same requirements as residents in all other specialties, including holding an appropriate medical degree (i.e., a degree from a U.S. or Canadian medical school, or—along with additional U.S. licensing requirements—a degree from an international medical school) and passing the United States Medical Licensing Examination.
Many residents in PM have prior board specialty certifications, particularly in the primary care specialties of family medicine, internal medicine, and pediatrics. Doctors of osteopathic medicine and doctors of what has been called allopathic medicine typically pursue the same graduate medical education opportunities, and in the context of PM residencies, no prescribed differences in training exist outside of those related to individual residents’ interests.
The typical length of a PM residency training program in the United States is three years, similar to most primary care residencies (residency training for other specialties in the United States can be four or five years in length). The first year usually entails either an internship (i.e., clinical training) in any of the ACGME-accredited specialties—commonly (but not exclusively) in a primary care specialty—or a transitional-year internship. Often, the internship year occurs at an institution other than the one sponsoring the PM residency program. The remaining two years of PM residency training consist of a combination of graduate education (academic work) leading to an MPH or equivalent degree, and practicum experiences in a particular subspecialty (AM, OM, or PH/GPM).
New ACGME requirements. New program training requirements implemented by the ACGME, which took effect in July 2011, have substantially changed the PM residency pathway. These new requirements emphasize the integration of the final 2 years of training (eliminating the possibility of a stand-alone academic year), specify a minimum amount of direct patient care depending on the specialty (2 months for PH/GPM and 4 months for AM and OM), and oblige residents to complete at least 2 months of experience in a governmental public health agency.28 The new requirements also set a minimum of 24 months of postinternship training, eliminating the potential for programs to grant advanced standing to incoming residents who have prior graduate medical education training or academic degrees. Finally, the new requirements call for 11 months of direct patient care in the internship year, substantially more than the 6 months that ABPM requires.28,29
Combined residency programs. Incorporating another specialty into a PM residency is becoming more common in the United States. Although the ACGME does not officially recognize PM combined residencies, individual specialty boards can approve them, and eight programs have thus far received approval (six in internal medicine and two in family medicine).30 The ACGME accredits each of the individual programs separately as long as each meets its own stand-alone requirements. The duration of the combined program is typically one year shorter than the programs would be if completed sequentially.31 These combined programs typically integrate the primary care and PM training curricula into a single program at one institution, providing concurrent training in both specialties. The possibility of combining training in two ABPM specialties (such as PH/GPM and OM) also exists because of the extensive overlap between the specialties.
Most residency programs in the United States are funded by Medicare and/or Medicaid through the Centers for Medicare and Medicaid Services, a branch of the Department of Health and Human Services (HHS).32 However, because PM residents do not typically train in environments that directly care for these patient populations, it is one of two specialties (along with pediatrics) that do not typically qualify for this funding. Limited funding is therefore available through a combination of private and public sources, both of which have been shrinking over the past several years. Private funds are obtained from supporting academic institutions, grants from national organizations such as the American Cancer Society, and payment for rotation services (i.e., salary support).33 Public funds come primarily through grants from the Health Resources Services Administration (HRSA), a separate branch of HHS, which is the federal agency primarily responsible for improving access to health care services for people who are uninsured, isolated, or medically vulnerable.34 HRSA funding is categorized as discretionary spending, so it is subject to the annual appropriations process in Congress, making it particularly vulnerable to budget cuts. Training funds have also recently been made available from the American Recovery and Reinvestment Act (commonly known as the “stimulus bill”) and the Public Health and Prevention Fund, which came into being as a result of the Patient Protection and Affordable Care Act.35 However, it is unclear whether these funds will be protected or extended beyond their current provision.
Availability of residency positions
In 2011, 621 ACGME-accredited slots in 71 programs were available for PM residents36; however, only 318 (51%) of these were filled. Although the last few years have seen a slight increase in the number of residents pursuing PM training (due to the temporary increased funding mentioned above), the overall trend has seen a steadily decreasing number of residents over the last decade due, primarily, to a lack of stable funding.33 PM has traditionally had low participation in the National Resident Matching Program; current data indicate that only a handful of applicants match through this system.37 Although some PM residencies select trainees for the clinical year and PM residency together, most residents use the NRMP to match for their clinical internship only and then complete an individual program application for their PM residency.
In the United States, the ABPM offers four pathways for board certification: residency, alternate, special, and complementary. Requirements common to all four include (1) graduation from an approved medical school, (2) current valid and unrestricted medical license (U.S. or Canadian), (3) one year of postgraduate clinical training accredited by an approved U.S. or Canadian governing body, (4) completion of the MPH or equivalent degree, (5) at least one practicum year in an accredited program, and (6) current practice in the specialty.29,38 Medical licensure varies by state and requires anywhere from one to three years of postgraduate medical education for an unrestricted license.39 Two written examinations (one core and one specialty) are required for board certification, but there is no oral component.29
The residency pathway as described above is the typical route to certification. The other pathways allow PM specialists to meet the academic and practicum requirements through specific courses and a combination of experience and training in other ABMS programs. The alternative pathway applies to those graduating from medical school before 1984, whereas the special pathway applies to those who hold a current certification in another ABPM specialty.29 The complementary pathway, which took effect in March 2011, is designed to accommodate those who make a midcareer switch to PM and requires only one year of residency.38
MOC for PM occurs on a 10-year recertification cycle. Recertification requires passing an examination, recording 100 hours of ABPM-approved MOC activities (30 hours every 3 years), and logging 150 hours in ABPM-approved continuing medical education pursuits (45 hours every 3 years). ABPM-approved MOC activities, which tend to be specific to the PM specialty, may include attendance at specialty annual conferences, participation in professional courses, or using online resources. Continuing medical education, typically required to maintain state licensure, tends to be more general to the medical profession.40 MOC and continuing medical education designations are not mutually exclusive, and approved activities may count for both.
Roles of specialists
PM physicians in the United States have a wide variety of jobs based primarily on preventing health problems prospectively. These include positions in all levels of government (federal, state, and local), in public health departments, in nongovernmental agencies, in the private sector (industry and corporations), and in academic institutions. Because of the relatively small specialty size and unique market demands for each specialty, matching residency training with job opportunities is a constantly evolving process.41 PM physicians take diverse career paths but, in general, practice similar skills to their counterparts in Canada, which include disease prevention, health promotion, outbreak investigations, international medicine, academic or research work, policy development, corporate medicine, and specialized clinical medicine.
Comparisons, Contrasts, and Considerations
An examination of postgraduate capacity for public health and preventive medicine training in Canada and the United States is timely given the growing challenges for the specialty on both sides of the border. Trends and shifts in demographics stand to present common challenges to population health efforts in both countries, while public health physicians in both systems continue to advocate appropriate funding for public health efforts as well as the training, graduation, and equitable distribution of an adequate workforce.
The Centers for Disease Control and Prevention (U.S.) has outlined 10 public health achievements over the past century that have significantly improved the health of populations in the industrialized world.42 These steps forward have not diminished the need for public health physicians. Rather, the ever-increasing complexity of health care systems requires public health specialists to objectively prioritize population health needs in order to provide efficient and effective patient care for all. Because Canada and the United States have similarities in culture, lifestyle, and infrastructure, preventive medicine specialists would benefit from an international collaboration focused on health research and policy which examines issues beyond traditional health protection functions. Such a collaboration could also help to maximize the limited resources devoted to public health. Famously underfunded, public health is colloquially referred to in Canada as the “three percent” (a reference to the 2004 Naylor Report which showed that only 3.5% of total health care spending in Canada goes to preventive efforts).43 Joining forces in this way, specialists could demonstrate the ultimate value of prevention by improving health and preserving scarce health care resources at the same time.
Workforce challenges on both sides of the border are highlighted by the growing demand for public health specialists, and in both countries, this greater demand is driven by increased societal awareness of the value of prevention. In 2006, the Ontario Medical Association issued a report44 on the public health system in that province in light of two high-profile events: (1) the 2000 Walkerton tragedy (the drinking water in the town of Walkerton, Ontario, was contaminated with Escherichia coli O157:H7), and (2) the 2003 outbreak of severe acute respiratory syndrome, which greatly affected the city of Toronto. The report found that 12 of the province’s 36 district health units did not have a full-time public health physician specialist serving as a medical officer of health.44
In the United States, several reports—with both a local45 and national23 focus—have detailed the shortage of public health professionals. Additionally, many physicians who practice public health are not specialty trained. Although they may have graduate education (e.g., an MPH degree) or practical experience, they have not completed dedicated residency training or certification in preventive medicine or public health. As in Canada, leadership positions in public health in the United States are often filled by nonphysicians, a reality that may mask the need for specialty-trained physicians. This shortage persists despite recent tragedies—Hurricane Katrina along the Louisiana and Mississippi Gulf Coast in 2005 and the 9/11 terrorist attacks in New York City, Washington, DC, and Shanksville, Pennsylvania, in 2001—which highlight the unique challenges the changing global geopolitical environment presents for public health.
Finally, both countries face challenges related to their respective licensure processes. Both Canada and the United States give responsibility for licensure to state and provincial governments, whereas specialty certification is overseen at the national level. This mismatch can potentially lead to conflicts in workforce planning, particularly if jurisdictions have different requirements.
Although commonalities between public health training in the United States and Canada exist, the systems have differences as well (Table 1). One notable point of comparison is the structure of both residency streams. Although both training systems integrate clinical training, graduate academic work, and practicum rotations, Canadian PHPM residents usually complete their clinical training in family medicine, whereas U.S. PM residents complete their primary residencies in a wide variety of clinical specialties—or no prior specialty at all. Compared with the public health practice (for PH/GPM) and specific clinical (for OM/AM) emphasis in PM in the United States, PHPM in Canada is traditionally research and administration based. This focus has fostered numerous linkages to family medicine and primary care, which, together with clinical requirements for RCPSC accreditation, have resulted in the de facto selection of family medicine as the clinical basis of training for Canadian PHPM specialists. Conversely, the growing popularity of combined programs in the United States could provide greater flexibility in recruiting applicants and addressing funding issues; however, where these dual-trained U.S. specialists ultimately practice is yet unknown. In both countries, experts with dual training who remain in primary care might accrue individual professional benefit from their public health training, but they will do little to alleviate the growing public health workforce shortage.
Another difference between public health training in the United States and in Canada is the duration of training. The shorter time to certification in the United States allows a more rapid response to changes in workforce demand. In addition, a single-track, preventive-medicine-focused program that incorporates sufficient clinical training in population health may provide more preparation for dealing with the issues unique to public health; most Canadian PHPM residents live in both the PHPM world and the family medicine world at the same time. Because no guidelines in the United States limit the prefellowship clinical training to a specific specialty, a greater number of qualified and interested trainees have the opportunity to pursue their interests in population health. At the same time, this flexibility could give rise to real and perceived inconsistencies; with less name recognition, employers may have more narrow expectations of specialists’ skill sets, which could hamper employment opportunities.
Other differences between Canadian and U.S. public health training exist in the location and funding of residency programs. Canadian residencies are housed exclusively in academic medical centers with a corresponding medical school, whereas U.S. residencies are located in a wide variety of settings, including some that are outside of traditional academic environments. Funding for resident salaries is provided by the provincial governments in Canada, a centralized and straightforward system with one stakeholder, whereas in the United States, funding is provided by a mixture of private funding and public grants, leading to a complicated system with multiple stakeholders. In the face of a looming U.S. public health workforce shortage, this complicated, mixed-funder system has created an uncertain and shrinking source of financial support in the United States and has harmed physician recruitment into the specialty.
A final difference exists in the governance structure of specialty training in both countries. Canada has a single body managing both residency education and specialty certification processes, whereas the United States has separate bodies managing each aspect. This system of shared management can be problematic; although communication and relationships between the agencies exist, conflicting requirements have created some discrepancies. For example, the complementary pathway offered by the ABPM, which requires 1 year of residency training in certain situations, is in conflict with the new ACGME requirements of 24 months of postinternship training.
Further assessment would be beneficial in determining whether the different training models produce different outcomes within each country’s preventive medicine community. Future researchers may examine the cooperation between colleagues (both public health and otherwise), the effects of diversity of expertise, the links between public health and primary care, and the impact on the public health workforce in an effort to identify the elements of an ideal training path.
Knowledge of the worldwide state of public health and preventive medicine benefits its practitioners. A greater evidence base supports the sharing of ideas and resources46 across borders and increases awareness of equivalent programs among countries—both of which, in turn, improve training outcomes. Allowing public health and preventive medicine professionals to quickly identify and inquire of one another provides benefit both on a routine basis and in the midst of crises, such as natural disasters or pandemics.47 A cross-border network of public health experts also permits greater information exchange and collaboration on best practices regarding emerging public health issues.48
We hope that our evaluation of public health physician specialty training in Canada and the United States helps to improve practitioners’ understanding of the parallel specialties in the neighboring countries. Further, we hope to facilitate new collaborations and connections between the U.S. and Canadian public health physician communities to improve collaboration, research, and discussion on a wide range of public health issues common to both sides of the border.
Acknowledgments: The authors gratefully acknowledge the comments and feedback provided by Dr. Bart Harvey, associate professor, Dalla Lana School of Public Health, University of Toronto, and Dr. David Mowat, medical officer of health, Peel Region Public Health Department.
Other disclosures: Dr. Peik is a member of the Residency Review Committee for Preventive Medicine, a committee of the Accreditation Council for Graduate Medical Education.
Ethical approval: Not applicable.
Disclaimers: The views expressed are those of the authors and should not be construed to represent the positions of the Department of the Army, Department of Defense, Accreditation Council for Graduate Medical Education, or Residency Review Committee for Preventive Medicine.