The following post is written by Angel N. Desai describing a local infectious disease challenge that she faces in her daily work.

As an infectious disease fellow in training in the United States, one of my frequent frustrations involves diagnostic stewardship. While in general, the adage of “more data is better” does ring true, ordering unnecessary laboratory tests without considering the implications of a positive result can often do more harm than good to patients. In the field of infectious disease, a patient’s personal history often affords the most important clues for coming to a diagnosis, and it is only when considering that history in conjunction with an individual’s pre-test probability that certain diagnostic tests should be considered. Unfortunately, laboratory tests are often ordered due to habit or concern that has been promulgated in medical teaching despite emerging evidence to the contrary. A recent study published in JAMA Surgery by Salazar et al. for example, discussed the routine ordering of urine cultures and treatment in the absence of symptoms in patients scheduled for non-urologic procedures. The study ultimately found that treatment of asymptomatic bacteriuria identified in preoperative urine cultures did not lead to reductions in the risk for postoperative infections [1]. Another study by Stohs et al. found that weekly outpatient surveillance blood cultures obtained from asymptomatic hematopoietic cell transplant recipients on high-dose steroids for treatment of acute graft-versus-host disease were frequently of low benefit and often led to an excess of antibiotic usage and unnecessary costs [2].

These papers offer a few examples of where diagnostic testing with murky indications not only result in higher financial burdens to a U.S. healthcare system already afflicted by skyrocketing costs, but also potentially adverse events for individual patients as well. On a day-to-day level, I am often confronted with a positive lab test with little clinical significance or relevance, often causing undue anxiety among consulting medical teams and patients. This can be a difficult avenue to navigate as a consultant, and I have spent much of my time in training considering how to resolve some of these issues. On a microscopic level, I have worked with our local infection control and quality and safety committees on trying to reduce some of the unnecessary urine cultures ordered on inpatients in the setting of negative urinalyses and/or symptoms. However, an emphasis on medical education in regard to appropriate indications and limitations of certain diagnostic tests is necessary for larger changes to be made in this arena. Cooperative learning and careful consideration of test characteristics are vital to advocating for stewardship as advances in laboratory testing produce more diagnostic tools in the future.

1. Salazar JG, O’Brien W, Strymish JM, Itani K, Branch-Elliman W, Gupta K. Association of Screening and Treatment for Preoperative Asymptomatic Bacteriuria with Postoperative Outcomes Among US Veterans. JAMA Surg. Published online December 12, 2018. Doi:10.1001/jamasurg.2018.4758.
2. Stohs E et al. Limited Utility of Outpatient Surveillance Blood Cultures in Hematopoeitic Cell Transplant Recipients on High-Dose Steroids for Treatment of Acute Graft-versus-Host Disease. Biol Blood Marrow Transplant. 2019 Feb 1. doi:10.1016/j.bbmt.2019.01.031.