Complexity of Infectious Diseases Compared With Other Medical Subspecialties

Abstract

Substantial attention has been given to the low compensation and declining fellowship applications in the field of infectious diseases (ID) [1–4]. We believe that the increasing complexity of our field is another important issue that deserves attention.

The breadth and complexity of a field of medicine is admittedly difficult to quantify and will be subject to debate. We sought to compare the field of ID with endocrinology, nephrology, and rheumatology, using available metrics. We chose to compare these other specialties because they are also primarily cognitive specialties without procedures and similar in size to ID.

Since UpToDate is the most widely used clinical resource for patient care [5] we enumerated its ID content. UpToDate is organized into specialties, sections, subsections, and articles. We enumerated the number of articles across the 4 specialties. This revealed that ID contained between 65% and 77% more articles than those of the other 3 specialties (n = 1402 vs 794–848 articles; see Figure 1 and Supplementary Data for exact numbers).

Figure 1.

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Comparison of internal medicine specialties by specialty-specific articles, society guidelines, new Food and Drug Administration (FDA)–approved medications, and starting faculty salaries. A, Numbers of UpToDate articles in each specialty section, as of 2 May 2023. B, Numbers of current evidence-based recommendations in specialty society guidelines (infectious diseases [ID], Infectious Diseases Society of America; endocrinology, Endocrine Society; nephrology, Kidney Disease: Improving Global Outcomes; and rheumatology, American College of Rheumatology). C, Numbers of FDA-approved new molecular entities from 1985 to 2022, for which the primary indication can be assigned to a specific specialty. D, Median assistant professor total compensation by specialty in 2022 (American Academy of Medical Colleges Faculty Salary Report [11]).

Likewise, professional societies produce practice guidelines that are widely used clinical resources. Each guideline is distilled into evidence based and graded recommendations. We enumerated the number of recommendations from active guidelines (ie, excluding archived guidelines). This revealed that the Infectious Diseases Society of America (IDSA) guidelines (n = 1903 recommendations) contained between 50% and 346% more recommendations than those of the Endocrine Society, Kidney Disease: Improving Global Outcomes, and the American College of Rheumatology. We also noted that the complexity of many guidelines has increased with time. For example, the aspergillosis guidelines increased from 14 pages in 2000 to 34 pages in 2008 and to 60 pages in 2016 [6–8].

Finally, we reviewed the new molecular entities or drugs approved by the Food and Drug Administration and assigned them to specialties based on their initial approved indication. Of 1199 new entities approved by the Food and Drug Administration from 1985 through 2021 [9], 189 (16%) have an ID indication, substantially more than the number ascribable to endocrinology, nephrology, or rheumatology.

Our message is not that the fields of endocrinology, nephrology, and rheumatology are simple. Their knowledge bases are also large, and we all take care of patients with extremely complicated disease processes and comorbid conditions. Indeed, one large study found that patient complexity was highest among those seen by nephrologists and ID physicians [10]. Rather, our argument is that the knowledge base required of the ID physician is increasingly complex. For example, in just 3 years UpToDate has produced 29 articles related to coronavirus disease 2019 (COVID-19), and the IDSA has 70 pages of guidelines on COVID-19. Given this ever-evolving complexity, we see a number of important implications for our field.

First, the complexity of ID clinical decision making is not adequately appreciated or compensated by payers. The physician work relative value unit is supposed to reflect the time and intensity associated with furnishing a service; however, there is no additional intensity that can be assigned because of the complexity of our field or decision making. Notably, according to the American Academy of Medical Colleges [11], the median total compensation for an assistant professor in ID is less than for the other specialties (Figure 1). The IDSA is well aware of this and has authored letters to Congress stating that ID reimbursement does not adequately reflect the value and complexity of care provided by ID clinicians [12]. In other fields such as business, law, and engineering, experts that command broad and deep expertise will generally receive greater compensation. We hope data such as these can be used to advocate for the complexity of our decision making and enhanced compensation.

Second, while the complexity of the field of ID may be appealing for some of us that entered the specialty, it may present an unattractive lifestyle choice for others, particularly when coupled with the low compensation of the field. Difficulty in mastering a field has been noted as a reason for declining interest in ID [13]. While the high complexity of our field cannot be reduced, we need to acknowledge it and identify ways to recruit in the face of it [14].

Third, how to educate future and current physicians on the large and increasing content of ID will become increasingly difficult. This affects not only our ID fellows but also medical residents and students who do not specialize in ID. The primary pedagogical method for ID material has been didactics and memorization [1]. This will become more difficult. For the 80% of US counties that do not have an ID physician already [15] general practitioners will need to manage infections amidst this increasing content. How to distill knowledge and guidelines to generalists will become increasingly challenging and important.

Fourth, how we practice as ID divisions and subspecialty groups may need to evolve. It will become harder for the general ID specialist to stay abreast of the latest information and evidence in all areas. Large ID groups and divisions may need to further develop sub-subspecialists within ID for optimal clinical care, much as oncology does.

In summary, the high complexity of the ID field is a reality and will likely increase. We believe that this complexity is inadequately captured by current compensation schemes and is likely a contributor to the declining applicant pool. The increasing body of ID knowledge content coupled with a flat or declining number of specialists is an ominous formula. These systemic trends will likely continue, and clinical care stands to worsen without significant structural reform.

Supplementary Data

Supplementary materials are available at Open Forum Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so questions or comments should be addressed to the corresponding author.

Acknowledgments

Author contributions. Both authors contributed to the writing and editing of this manuscript.

Financial support. This work was supported by the National Institutes of Health (grants K24AI102972 to E. H. and T32 AI007046 to B. G.).

References

Author notes