Many recent randomized controlled trials in the field of septic shock failed to demonstrate a benefit on mortality. Randomized controlled trials increasingly report organ support duration and organ support-free days as primary or secondary outcomes. We conducted a methodologic systematic review to assess how organ support outcomes were defined and reported in septic shock randomized controlled trials.
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We included randomized controlled trials published between January 2004 and March 2018 that involved septic shock adults and assessed organ support duration and/or organ support-free days for hemodynamic support, respiratory support, or renal replacement therapy.
For each randomized controlled trial, we extracted the definitions of organ support duration and organ support-free days. We particularly evaluated how nonsurvivors were accounted for. Study authors were contacted to provide any missing information regarding these definitions.
We included 28 randomized controlled trials. Organ support duration and organ support-free days outcomes were reported in 17 and 15 randomized controlled trials, respectively, for hemodynamic support, 15 and 15 for respiratory support, and five and nine for renal replacement therapy. Nonsurvivors were included in the organ support duration calculation in 13 of 14 randomized controlled trials (93%) for hemodynamic support and nine of 10 (90%) for respiratory support. The organ support-free days definition for hemodynamic support, respiratory support, and renal replacement therapy was reported in six of 15 randomized controlled trials (40%), eight of 15 randomized controlled trials (53%), and six of nine randomized controlled trials (67%) reporting an organ support-free days outcome, respectively. Of these, one half assigned “0” to nonsurvivors, and the other half attributed one point per day alive free of organ support up to a predefined time point.
This study highlights the heterogeneity and infrequency of organ support duration/organ support-free days outcome reporting in septic shock trials. When reported, the definitions of these outcome measures and methods of calculation are also infrequently reported, in particular how nonsurvivors were accounted for, which may have an important impact on interpretation.