Global evidence, local research: a country map of included studies from Cochrane Systematic Reviews

Article type
Authors
Yao L1, Cui R1, Wang X1, Wang Q1, Wei D1
1Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, China
Abstract
Background: Cochrane Systematic Reviews (SRs) are one source of high quality evidence, which are widely used in many countries in the development of clinical practice guidelines and health policies. However, worldwide, different ethnic groups have different tolerance levels to the same intervention. So it is important to analyze the geographical distribution of included studies from Cochrane SRs.
Objectives: To analyze the geographical distribution of included studies from Cochrane SRs.
Methods: Three-hundred Cochrane SRs with full text were randomly selected by computer from the Cochrane Database of Systematic Reviews (CDSR), and the countries or regions of their included studies were analyzed.
Results: The 300 Cochrane SRs included 2456 original studies. Among these 2456 studies, 1033 (42%) were conducted in Europe, 779 (32%) were conducted in North America, 442 (18%) were conducted in Asia, 107 (4%) were conducted in Oceania, 60 (3%) were conducted in Africa and 35 (1%) were conducted in South America.
Conclusions: Seventy-five per cent of studies were conducted in Europe and North America. Few original studies come from Asia, South America, Africa and Oceania. The unbalanced geographical distribution of original studies might cause indirectness when the Cochrane SRs are disseminated throughout the world.