Core Outcomes in Critical Care: Development of a Core Outcome Set in Aneurysmal Subarachnoid Haemorrhage Clinical Research

Abstract

Aneurysmal subarachnoid haemorrhage (aSAH) is a catastrophic type of stroke with high mortality and morbidity. In contrast to the dramatic improvements in ischaemic stroke care, there has been no major changes in aSAH management over the past 20 years. One issue that may be limiting progress is the use of inconsistent, inappropriate, or insensitive outcome measures.

Our systematic review of aSAH research identified 129 trials that used 51 unique primary outcomes. The most common measures used were functional scales for neurological conditions that have different pathophysiology, epidemiology and long-term sequelae compared to aSAH. Measures of cognition and health related quality of life (HRQOL) were reported rarely.

At a multistakeholder workshop we built consensus around improving outcome selection in aSAH by developing a core outcome set (COS). A COS is a limited set of outcome measures that are recommended to be reported in all aSAH studies. It will ensure that we are selecting the right aspects of health (domains) at the right timepoints using the best available measurement instruments.

To inform domain selection we conducted two international surveys. A q-method survey revealed distinct viewpoints among stakeholders. HRQOL was the highest ranked domain followed by independence and function. In a Delphi survey the highest ranked domains were cognition and function, with domains such as aneurysm obliteration, rebleeding, HRQOL and mood also in the top 10. These results confirm a mismatch between outcomes used by researchers and those prioritised by stakeholders.

The results of the surveys were then presented to a second multistakeholder consensus workshop that generated a list of 4 core outcome domains: mortality, function, cognition and HRQOL. Further work is required to determine the ideal timepoints and best measurement instruments. This thesis improves outcome selection in aSAH research by addressing the current mismatch and provides the basis for a COS.