In medical research, the quality of data is the key to success. Thus, data quality control becomes an important part of ensuring the research's high quality. REDCap system is an emerging data acquisition system in medical research, which is gradually applied in research at home and abroad. It is a hot issue to realize double data entry and data quality control in using the REDCap system, which researchers are concerned about when this system is supposed to apply. This article will systematically introduce how to use the REDCap system for double data entry and quality control from the aspects of research project creation, data collection tool design, double data entry, data checking and exporting.

Hemophagocytic syndrome (HPS), which is currently named as hemophagocytic lymphohistiocytosis (HLH), is a hyperinflammatory syndrome characterized by persistent fever, hepatosplenomegaly, pancytopenia and hemophagocytosis found in bone marrow, liver, spleen and lymph nodes due to excessive activation of macrophages and cytotoxic T cells. Macrophage activation syndrome (MAS) is a specific form of HLH induced by autoinflammatory/autoimmune disorders which can be life-threatening and requires multiple disciplines. In order to improve clinicians′ understanding of MAS and standardize the clinical diagnosis and treatment practice of MAS, the rheumatology branch of Chinese Rheumatology Association organized domestic experts to formulate the diagnosis and treatment standard, in order to improve the diagnosis and treatment level of MAS and improve the prognosis of patients.