The Value of Infectious Disease Specialists in Oncology Practices Remains Cloudy

Bruno P. Granwehr, MD, MS

Patient care is shifting from inpatient to outpatient settings, especially in oncology. And while consultations with infectious disease specialists often take place in the inpatient setting, the use of infectious disease services in the outpatient setting needs further investigation. A study in Current Opinions in Oncology suggests that the value added by these specialists could improve outcomes and reduce drug utilization, length of stay, and readmissions in an aging, and increasingly complex, cancer population. It’s estimated that by 2025, the costs of infection in cancer patients over 65 years of age will increase by as much as 45%¹.

Data from the general population demonstrate the value of infectious disease consultation in specific infections, antibiotic stewardship, infection control, and quality improvement, according to authors Bruno P. Granwehr, MD, MS, and Dimitrios P. Kontoyiannis, MD, MS, ScD, both from The University of Texas, MD Anderson Cancer Center.

In the cancer setting, however, there are fewer studies. Singer et al² showed a significant decrease in mortality from 20.5 to 9.9% in patients with fungemia and bacteremia when infectious disease specialists were consulted in patient care. And Pongas et al³ described the outpatient practice of two infectious diseases specialists from 1998 to 2008.

In the Pongas study, among patients referred to infectious disease specialists, 53% had a solid tumor, 8% were severely neutropenic, and 17% were receiving high-dose corticosteroids. Patients were referred from the leukemia, surgical oncology, and stem cell transplantation services. In contrast to the general infectious diseases setting, 35% of referrals (compared to 54.3% ⁴) were exclusively for management, whereas 42% were for diagnosis and management, and 22% for diagnosis alone.

The infectious diseases physicians provided alternative diagnoses in 53% of consultations, suggesting different types of infection in 46%, and noninfectious etiologies in 29% of consults. Similar to the general infectious diseases setting, 14% of consultations were for skin and soft tissue infection. In contrast to the general infectious diseases setting, diagnosis and/or management of pulmonary nodules or infiltrates composed 31% of consultations—almost twice as much as the general infectious diseases setting. The infectious diseases consultants initiated antimicrobial therapy in 31% and discontinuation of antibiotics in 5% of cases.

The value that infectious disease specialists bring in the inpatient setting is established, but because of the limited body of evidence for infectious disease in the outpatient cancer setting, the authors concluded that “further work needs to be done to characterize the impact of infectious diseases consultation specifically for cancer patients.”

References

1. Cooksley CD, Avritscher EB, Rolston KV, Elting LS. Hospitalizations for infection in cancer patients: impact of an aging population. Support Care Cancer 2009; 17:547—554.
2. Singer C, Kaplan MH, Armstrong D. Bacteremia and fungemia complicating neoplastic disease. A study of 364 cases. Am J Med 1977; 62:731—742.
3. Pongas G, Hamilos G, Rolston KV, Kontoyiannis DP. Formal adult infectious disease specialist consultations in the outpatient setting at a comprehensive cancer center (1998—2008): diverse and impactful. Support Care Cancer 2012; 20:261—265.
4. Grupper M, Potasman I. Formal adult infectious disease outpatient consultations: a retrospective 6-year survey. Infection