Antibiotic Prescribing and Respiratory Viral Testing for Acute Upper Respiratory Infections Among Adult Patients at an Ambulatory Cancer Center

Background. Outpatient antibiotic prescribing for acute upper respiratory infections (URIs) is a high-priority target for antimicrobial stewardship that has not been described for cancer patients. Methods. We conducted a retrospective cohort study of adult patients at an ambulatory cancer center with URI diagnoses from 1 October 2015 to 30 September 2016. We obtained antimicrobial prescribing, respiratory viral testing, and other clinical data at first encounter for the URI through day 14. We used generalized estimating equations to test associations of baseline factors with antibiotic prescribing. Results. Of 341 charts reviewed, 251 (74%) patients were eligible for analysis. Nearly one-third (32%) of patients were prescribed antibiotics for URIs. Respiratory viruses were detected among 85 (75%) of 113 patients tested. Antibiotic prescribing (P =.001) and viral testing (P <.001) varied by clinical service. Sputum production or chest congestion was associated with higher risk of antibiotic prescribing (relative risk [RR], 2.3; 95% confidence interval [CI], 1.4-3.8; P <.001). Viral testing on day 0 was associated with lower risk of antibiotic prescribing (RR, 0.4; 95% CI 0.2-0.8; P =.01), though collinearity between viral testing and clinical service limited our ability to separate these effects on prescribing. Conclusions. Nearly one-third of hematology-oncology outpatients were prescribed antibiotics for URIs, despite viral etiologies identified among 75% of those tested. Antibiotic prescribing was significantly lower among patients who received an initial respiratory viral test. The role of viral testing in antibiotic prescribing for URIs in outpatient oncology settings merits further study.