Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In their meta-analysis of randomized controlled trials of folic acid supplementation and risk of cardiovascular disease, Dr Bazzano and colleagues1 provided a clear description of their inclusion criteria and study selection process. Using multiple databases when searching for studies that meet meta-analysis inclusion criteria may help avoid selection bias.2 Failure to search multiple health databases can result in missing up to half of the relevant literature.3
Mahid SS, Minor KS, Galandiuk S. Folic Acid Supplementation and Cardiovascular Diseases. JAMA. 2007;297(14):1549-1550. doi:10.1001/jama.297.14.1549-a