Study published on the effect of antimicrobial treatment duration
01.02.2023 – A new study from Switzerland investigated the effect of antimicrobial treatment duration on in-hospital mortality in critically ill patients. There was no evidence for a survival difference between patients who received a shorter treatment (<10 days) vs a longer treatment (more than 10 days).
The study used retrospective data from two tertiary care intensive care units in Switzerland (Inselspital Bern and CHUV Lausanne). Such a retrospective data analysis might be prone to immortal time bias. Immortal time bias occurs when the treatment allocation happens after the baseline assessment time point. Here, treatment duration was determined after the start of the antimicrobial treatment and not - as for example in a randomized controlled trial - on the day of diagnosis. Besides the clinical results, the researchers were able to show, that a naïve survival analysis would lead to a biased result in favor of the longer treatment duration group. More sophisticated statistical methods are needed to be able to avoid biased and spurious findings. The study results add to the existing evidence from other observational studies on the duration of antimicrobial treatment in critically ill patients. Results from an ongoing randomized controlled trial (BALANCE trial, NCT03005145) are still awaited.