Failure of an effective physiologic threshold compliance tool to demonstrate benefit in a clinical trial of traumatic brain injury patients

Abstract

Background: Better physiologic threshold compliance holds promise for improving outcomes in neurocritical care patients.

Methods: Our group developed a threshold compliance tool. This software computes and displays the proportion of values out of range in real time. We captured intracranial pressure (ICP) measures in our patients before and after implementation of this technology. Ten months after the threshold compliance tool was introduced we initiated a randomized controlled trial involving acute traumatic brain injury (TBI) patients to assess whether the tool was effective at reducing out-of-range ICP values.

Results: A total of 54 patients with ICP monitors were included in our analysis, 42 of whom sustained a TBI. Implementation of the threshold compliance tool was associated with an 85.3% reduction in ICP values exceeding 22 mmHg in neurocritical care patients (p = 0.004) and a 76.8% reduction in patients with TBI (p = 0.043). Out-of-range values in an area-under-the-curve analysis were reduced by 78.8% in all patients (p = 0.009) and in TBI patients by 77.9% (p = 0.051). Out-of-range values were not further reduced during our randomized controlled trial examining the threshold compliance tool, and a difference between treatment groups was not suggested.

Conclusions: Implementation of a threshold compliance tool was associated with a marked and significant reduction in out-of-range ICP values. Benefit was, however, not evident in a randomized controlled trial. Our analysis provides a unique perspective on our failure to detect an apparent true difference and may provide insights into other neurotrauma trial failures.

Keywords: Compliance; Failure; Head injury; Intracranial pressure; Neurocritical care; Neuromonitoring; Technology; Threshold; Traumatic brain injury; Trial.