Krewulak KD, et al. - Researchers evaluated risk factors as well as results for each delirium subtype (hypoactive, hyperactive and mixed) in an adult ICU population, via this systematic review. They explored MEDLINE, Embase, CINAHL, SCOPUS, Web of Science and PsycINFO databases and identified 9,635 relevant abstracts, of which, 20 studies were included. They found no link of sex with any delirium subtype in 4/4 (100%) studies. A total of 4/7 (57%) studies revealed a consistent link of mortality with hypoactive delirium. Across studies, inconsistent evidence was identified in support of the link of Acute Physiology and Chronic Health Evaluation II score, mechanical ventilation, length of stay, duration of delirium and removal of tubes. Despite providing data on many subtype-specific risk factors and outcomes, the included studies showed heterogeneity in terms of reporting and methodological quality, which limited the generalizability of the outcomes. Across studies, the proof for several subtype-specific risk factors or results was found to be inconsistent. It is crucial to have a standardized methodology as well as a universal template for gathering data in ICU delirium studies; assisting to recognize subtype-specific risk factors or results and reinforce the link of potential risk factors or outcomes.