Intelligence outcome of pediatric intensive care unit survivors: a systematic meta-analysis and meta-regression.

Background: Long-term morbidity after pediatric intensive care unit (PICU) admission is a growing concern. Both critical illness and accompanying PICU treatments may impact neurocognitive development as assessed by its gold standard measure; intelligence. This meta-analysis and meta-regression quantifies intelligence outcome after PICU admission and explores risk factors for poor intelligence outcome.

Methods: PubMed, Embase, CINAHL and PsycINFO were searched for relevant studies, published from database inception until September 7, 2021. Using random-effects meta-analysis, we calculated the standardized mean difference in full-scale intelligence quotient (FSIQ) between PICU survivors and controls across all included studies and additionally distinguishing between PICU subgroups based on indications for admission. Relation between demographic and clinical risk factors and study's FSIQ effect sizes was investigated using random-effects meta-regression analysis.

Results: A total of 123 articles was included, published between 1973 and 2021, including 8,119 PICU survivors and 1,757 controls. We found 0.47 SD (7.1 IQ-points) lower FSIQ scores in PICU survivors compared to controls (95%CI -0.55 to -0.40, p < .001). All studied PICU subgroups had lower FSIQ compared to controls (range 0.38-0.88 SD). Later year of PICU admission (range 1972-2016) and longer PICU stay were related to greater FSIQ impairment (R = 21%, 95%CI -0.021 to -0.007, p < .001 and R = 2%, 95%CI -0.027 to -0.002, p = .03, respectively), whereas male sex and higher rate of survivors were related to smaller FSIQ impairment (R = 5%, 95%CI 0.001 to 0.014, p = .03 and R = 11%, 95%CI 0.006 to 0.022, p < .001, respectively). Meta-regression in PICU subgroups showed that later year of PICU admission was related to greater FSIQ impairment in children admitted after cardiac surgery and heart- or heart-lung transplantation. Male sex was related to smaller FSIQ impairment in children admitted after cardiac surgery. Older age at PICU admission and older age at follow-up were related to smaller FSIQ impairment in children admitted after heart- or heart-lung transplantation.

Conclusions: PICU survivors, distinguished in a wide range of subgroups, are at risk of intelligence impairment. Length of PICU stay, female sex and lower rate of survivors were related to greater intelligence impairment. Intelligence outcome has worsened over the years, potentially reflecting the increasing percentage of children surviving PICU admission.