Changes in critically ill cancer patients’ short-term outcome over the last decades: results of systematic review with meta-analysis on individual data

Purpose: The number of averted deaths due to therapeutic advances in oncology and hematology is substantial and increasing. Survival of critically ill cancer patients has also improved during the last 2 decades. However, these data stem predominantly from unadjusted analyses. The aim of this study was to assess the impact of ICU admission year on short-term survival of critically ill cancer patients, with special attention on those with neutropenia. Methods: Systematic review and meta-analysis of individual data according to the guidelines of meta-analysis of observational studies in epidemiology. Datasource: Pubmed and Cochrane databases. Eligibility criteria: Adult studies published in English between May 2005 and May 2015. Results: Overall, 7354 patients were included among whom 1666 presented with neutropenia at ICU admission. Median ICU admission year was 2007 (IQR 2004–2010; range 1994–2012) and median number of admissions per year was 693 (IQR 450–1007). Overall mortality was 47.7%. ICU admission year was associated with a progressive decrease in hospital mortality (OR per year 0.94; 95% CI 0.93–0.95). After adjustment for confounders, year of ICU admission was independently associated with hospital mortality (OR for hospital mortality per year: 0.96; 95% CI 0.95–0.97). The association was also seen in patients with neutropenia but not in allogeneic stem cell transplant recipients. Conclusion: After adjustment for patient characteristics, severity of illness and clustering, hospital mortality decreased steadily over time in critically ill oncology and hematology patients except for allogeneic stem cell transplant recipients.