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

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. Systematic review and meta-analysis of individual data according to the guidelines of meta-analysis of observational studies in epidemiology. Pubmed and Cochrane databases. Adult studies published in English between May 2005 and May 2015. 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. 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.