Blog | Friday, March 2, 2018

Diagnostic stewardship is all the rage!


Dan Morgan recently blogged here about diagnostic stewardship, referencing a JAMA viewpoint we published last year, and I'll be presenting on the topic at the Remington Winter Course next month (join us!). So I wanted to draw attention to an excellent commentary just published in Infection Control & Hospital Epidemiology on diagnostic stewardship for health care-associated infections (HAIs), outlining opportunities and challenges. The key table outlines the strengths of various diagnostic stewardship strategies.

Also, in a great example of the need for diagnostic stewardship for HAIs, Clare Rock, MB Bch, MS, and colleagues just published this observational study in the American Journal of Infection Control. They retrospectively reviewed 18 months of surveillance for hospital-onset Clostridium difficile infection (HO-CDI) “LabID events” reported to the CDC's National Healthcare Safety Network.

For those not acquainted with the NHSN LabID event metrics, they do not consider patient-level clinical variables—only lab results and admission/testing dates. Of the 490 HO-CDI cases that occurred during the study period, chart review determined that 206 (42%!) of them were not likely to represent “true” CDI. In about half of “untrue” cases there was no significant diarrhea (defined as 3 or more loose stools in 24 hours), in 41% the patient had received a laxative in the prior 48 hours, and in almost 10% of cases the symptom onset was prior to the “hospital-onset” criterion but testing was delayed.

Graphs in the study demonstrate how improved test utilization could have changed their publicly-reported (and reimbursement-linked) HO-CDI rates. Of course the standardized infection ratio data assumes that no other hospitals implemented similar diagnostic stewardship programs …

When I talk about diagnostic stewardship to my laboratory colleagues, they often seem a bit puzzled—”OK, please don't test patients with low pre-test likelihood of disease—isn't that just diagnostics 101?” So why is the issue gaining more traction now? I think it's due to advances in diagnostic technology and changes in health care delivery. Our tests are becoming more sensitive and expansive (e.g. “syndromic” panels that detect dozens of targets in one fell swoop), and at the same time clinicians are seeing more patients in shorter periods of time and have less time to think about the tests they order—leading to more reliance on technology and less reliance on the careful history and exam findings that are required to generate thoughtful assessments of pre-test disease likelihood.

Also, I used to trudge 5 miles through 12 inches of snow to get to grade school, and kids these days ….

Finally, view this apt comic from the Journal of Clinical Microbiology's excellent new micro-comic series.

Daniel J. Diekema, MD, FACP, practices infectious diseases, clinical microbiology, and hospital epidemiology in Iowa City, Iowa, splitting time between seeing patients with infectious diseases, diagnosing infections in the microbiology laboratory, and trying to prevent infections in the hospital. This post originally appeared at the blog Controversies in Hospital Infection Prevention.