Methodology: 3.5/5
Usefulness: 3.5/5

Ann Intern Med. 2019 Oct 15;171(8):547-554. Cheng MP, et al.

Question and Methods: Multi-center diagnostic study that investigated the sensitivity of post-antimicrobial blood cultures compared to pre-antimicrobial blood cultures in severe sepsis.
Findings: The absolute difference in pre-antimicrobial (102/325 (31.4%)) compared to post-antimicrobial blood cultures (63/325 (19.4%)) was 12.0% (5.4%-18.6%;< 0.001) yielding a sensitivity of 52.9% (42.8%-62.9%).
Limitations: Recruitment while investigators were on-site with an average of 1 enrollment per site per month.  Low number of culture positives.

Interpretation: This practical study quantifies the decreased sensitivity of post-antimicrobial blood cultures with time and lays the groundwork for future research investigating impact on patient-centered outcomes.

By: Dr. Jessica McCallum

Hans Rosenberg
Dr. Rosenberg is an emergency physician at the Ottawa Hospital, assistant professor at the University of Ottawa, and Director of the Digital Scholarship and Knowledge Dissemination Program.