title: Intensive care unit mortality trends in children after hematopoietic stem cell transplantation: a meta-regression analysis.
abstract: BACKGROUND
  There is ongoing discussion whether intensive care unit mortality has decreased over time for children after hematopoietic stem cell transplantation.
  
  
  OBJECTIVE
  To analyze intensive care unit mortality trends in children after hematopoietic stem cell transplantation.
  
  
  METHODS
  Search of MEDLINE, EMBASE, and Cochrane databases, and a manual review of reference lists.
  
  
  METHODS
  Prospective and retrospective cohort studies containing intensive care unit mortality data of children after hematopoietic stem cell transplantation.
  
  
  METHODS
  Mortality statistics and features associated with mortality were abstracted from studies of interest. To assess mortality over time, the median years of inclusion in original studies were included as risk factor. A multiple random-effects meta-regression analysis was conducted to assess the independent contribution of prognostic factors on mortality.
  
  
  RESULTS
  Twenty-three studies were included, reporting on 1101 intensive care unit admissions. Overall intensive care unit mortality was 60% (range, 25%-91%). Once mechanical ventilation was necessary (n = 822), mean intensive care unit mortality was 71% (range, 25%-91%). Over the years, significantly fewer intensive care unit admitted patients received mechanical ventilation (p < 0.001). Univariable analysis in all intensive care unit admitted patients showed a significant decrease in mortality associated with year of inclusion. Mechanical ventilation and pulmonary disease were associated with increased mortality. In the multiple meta-regression analysis, only pulmonary disease remained significantly associated with mortality (odds ratio = 1.21, 95% confidence interval 1.01-1.46 per 10% increase in the number of patients with pulmonary disease in studies). The association between year of inclusion and intensive care unit mortality was less pronounced (odds ratio = 0.92, 95% confidence interval 0.84-1.01).
  
  
  CONCLUSIONS
  There is a widely held impression that intensive care unit mortality clearly decreased in children after hematopoietic stem cell transplantation. However, characteristics of intensive care unit admitted patients significantly changed over time. After correcting for this, an improvement in intensive care unit survival was less evident. More studies are needed before a true improvement in intensive care unit survival can be confirmed.
authors.affiliation: Department of Pediatrics, the Pediatric Intensive Care Unit, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands. j.vangestel@umcutrecht.nl
authors.forename: Josephus P J
authors.initials: JP
authors.lastname: van Gestel
authors.forename: Casper W
authors.initials: CW
authors.lastname: Bollen
authors.forename: Ingeborg
authors.initials: I
authors.lastname: van der Tweel
authors.forename: Jaap Jan
authors.initials: JJ
authors.lastname: Boelens
authors.forename: Adrianus J
authors.initials: AJ
authors.lastname: van Vught