The science of evidence synthesis in hematopoietic stem-cell transplantation: Meta-analysis and quality assessment

Abstract

A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. After being introduced in the 1970s, meta-analysis significantly influenced decision making in many scientific disciplines, helping to establish evidence-based medicine and to resolve seemingly contradictory research outcomes. Since the first meta-analysis on autologous hematopoietic stem-cell transplantation (HSCT) was published in 1989, the implementation of the method into research and clinical guidance in hematopoietic stem-cell transplantation faced challenges specific to the field. Here, we take the opportunity provided by the recent fortieth anniversary of meta-analysis to reflect on the accomplishments, limitations, and developments in the field of research synthesis in HSCT by summarizing the main methodological features of meta-analysis and its extensions, and by exemplifying the power and evolution of evidence synthesis in HSCT.