Investigating the impact of physical activity interventions on delirium outcomes in intensive care unit patients: A systematic review and meta-analysis.

Background: To investigate the impact of physical activity interventions, including early mobilisation, on delirium outcomes in critically ill patients. Methods: Electronic database literature searches were conducted, and studies were selected based on pre-specified eligibility criteria. Cochrane Risk of Bias-2 and Risk Of Bias In Non-randomised Studies-of Interventions quality assessment tools were utilised. Grading of Recommendations, Assessment, Development and Evaluations was used to assess levels of evidence for delirium outcomes. The study was prospectively registered on PROSPERO (CRD42020210872). Results: Twelve studies were included; ten randomised controlled trials one observational case-matched study and one before-after quality improvement study. Only five of the included randomised controlled trial studies were judged to be at low risk of bias, with all others, including both non-randomised controlled trials deemed to be at high or moderate risk. The pooled relative risk for incidence was 0.85 (0.62-1.17) which was not statistically significant in favour of physical activity interventions. Narrative synthesis for effect on duration of delirium found favour towards physical activity interventions reducing delirium duration with median differences ranging from 0 to 2 days in three comparative studies. Studies comparing varying intervention intensities showed positive outcomes in favour of greater intensity. Overall levels of evidence were low quality. Conclusions: Currently there is insufficient evidence to recommend physical activity as a stand-alone intervention to reduce delirium in Intensive Care Units. Physical activity intervention intensity may impact on delirium outcomes, but a lack of high-quality studies limits the current evidence base.