Purposeful microbiology comment added to urine cultures with Staphylococcus aureus increases orders for follow-up blood cultures

Abstract

Introduction. Patients with Staphylococcus aureus bacteriuria (SABU) often have underlying invasive disease, including S. aureus bacteremia (SAB). It has been proposed that most patients with SABU should have a blood culture done to rule out SAB. A preliminary audit suggested that our local hospitals had a low rate of follow-up blood culture orders for patients with SABU. In response to this, our microbiology laboratory changed the comment appended to urine cultures with growth of S. aureus to make a more assertive link between SABU and SAB and to recommend follow-up blood cultures. Aim. We designed a retrospective quasi-experimental study to see if the change in microbiology comment wording had an effect on clinician behaviour. We hypothesized that this simple comment change to make a more assertive link between SABU and SAB would lead to an increase in follow-up blood culture orders. Methodology. We used microbiology records to identify adult patients with urine cultures positive for Staphylococcus aureus at three acute-care hospitals in Hamilton, Ontario, Canada, for 1 year pre- and post-intervention. We recorded urine and blood culture results, timing, patient demographics, and in-hospital mortality. Results. A total of 243 adult patients with urine cultures with S. aureus were identified for inclusion. The primary outcome was met, as there was a significant increase in blood culture orders between the pre-intervention and post-intervention groups (66.9 % vs 80.4 %). This difference was mainly driven by an increase for emergency department and urgent care patients (30.6 % vs 63.6 %). The inpatient group had a high baseline rate of blood culture orders that did not change significantly (80.0 % vs 84.7 %). There was no significant change in detection of SAB (23.5 % vs 32.7 %) or inpatient mortality (18.0 % vs 24.7 %). Conclusion. Our study shows that a simple, purposeful comment appended to urine cultures with S. aureus leads to a significant increase in follow-up blood culture orders.

Staphylococcus aureus bacteriuria: implications and management

“…Microbiology comments on reports of urine cultures positive for S. aureus can be useful in guiding clinicians. 19 An appended comment suggesting repeat culture or blood cultures if the patient is unwell, or referring the clinician to a local guideline, and with prompts such as highlighting the need to treat in pregnancy, could be the basis for future work and service improvement.…”

Limited impact of a nudge comment in promoting de-escalation to first-generation cephalosporins in urinary tract infections

“…[4][5][6] Nudges have reduced inappropriate treatment of asymptomatic bacteriuria, decreased broad-spectrum antibiotic use, and increased collection of blood cultures after isolating Staphylococcus aureus from urine cultures. [7][8][9] These nudges suggested a specific action or noted the presence or absence of a bacteria or symptomatology. Our nudge promoted the linkage of 2 pieces of information to guide decision making: syndrome and MIC.…”