Methods of functional outcome assessment in neurocritical care trials: A systematic review and meta-analysis

Background: Acute brain injury due to conditions such as subarachnoid haemorrhage and traumatic brain injury are associated with physical, psychological, cognitive, emotional, and social deficits. Despite reductions in morbidity and mortality, there have been few significant changes in clinical practice. It has been suggested that heterogeneity in outcome assessment in studies has contributed to this limited progress.

Objectives: The objectives of this study were to describe current methods of outcome assessment in aneurysmal subarachnoid haemorrhage and traumatic brain injury studies and to examine the relationship between methods of outcome assessment and reported outcomes.

Methods: We performed a systematic review and meta-analysis of randomised controlled trials and cohort studies enrolling an adult aneurysmal subarachnoid haemorrhage or traumatic brain injury population and reporting at least one functional outcome measure.

Results: We identified 176 studies, including 60 494 participants. The Glasgow Outcome Scale or the Glasgow Outcome Scale Extended was used in 68% (N = 120) of studies and the Modified Rankin Scale in 38% (N = 67) of studies. Outcome assessment was reported at different timepoints, using different methods of application, and often dichotomised using different ranges. Many studies did not report key details on methods of outcome assessment. Outcome assessment using the Modified Rankin Scale was associated with a higher proportion of patients reported as having a favourable outcome 0.62 (95% confidence interval [CI]: 0.58-0.67) than the Glasgow Outcome Scale 0.48 (95% CI: 0.43-0.53) or the Glasgow Outcome Scale Extended 0.42 (95% CI: 0.37-0.48, p < 0.01). In-person assessment was associated with an increased proportion of patients achieving a favourable outcome 0.55 (95% CI: 0.55-0.45) compared to telephone assessment 0.46 (95% CI: 0.40-0.52).

Conclusion: There is significant heterogeneity and incomplete reporting of methods of outcome assessment in critical care studies enrolling aneurysmal subarachnoid haemorrhage and traumatic brain injury patient populations. Our study identified an association between the methods of outcome assessment and reported outcomes. Our study supports initiatives to standardise outcome assessment in neurocritical care research to ensure the quality of outcome data.

Registration: The International Prospective Register of Systematic Reviews (CRD42023072206).