Prevalence and incidence of ICU delirium and pain: a systematic review and meta-analysis.

PURPOSE We performed a secondary analysis of a prior systematic review and meta-analysis to examine the prevalence and incidence of ICU delirium and pain. METHODS The original search examined MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled trials from inception to May 15, 2023 (PROSPERO ID: CRD42022367715). Articles eligible for the current study derived from those previously reviewed at full text review. Included in the current study were randomised or observational studies among critically ill adults, that reported delirium or pain incidence or prevalence. Proportion data was transformed using the Freeman-Tukey double arcsine method prior to pooling using a random effects meta-analysis model. Joanna Briggs' Institute prevalence checklist was used for risk of bias. RESULTS From 517 full-text articles, 213 original studies, 226 publications (183,285 patients) were included. The pooled delirium prevalence (173 studies) was 35.7% (95%CI 32.4-39.0%). The most common delirium subtype was hypoactive (16.5%, 95%CI 12.1-21.4%). The pooled delirium incidence (41 studies) was 28.8% (95%CI 23.2-34.8%). The pooled pain prevalence (11 studies) was 43.5% (95%CI 28.6-58.9%). Delirium prevalence but not incidence decreased since 2013 (before: 39.9%, 95%CI 34.7-45.3% vs. after: 32.3%, 95%CI 28.2-36.5%, p = 0.02). Pain prevalence decreased significantly since publication of pain, agitation and delirium guidelines in 2013 (before: 64.6%, 95%CI 41.6-84.6% vs. after: 35.8%, 95%CI 20.5-52.6%, p = 0.046). CONCLUSIONS Delirium and pain prevalence among adults admitted to ICUs have decreased since publication of pain, agitation and delirium guidelines. However, both remain common, occurring in up to one-half of patients.