Letter to the editor: Bias estimation of predictors and internal validity of the study "Admission characteristics predictive of in-hospital death from hospital-acquired sepsis: A comparison to community-acquired sepsis"
1 Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Reproductive Endocrinology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
2 Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: mohammadpanahi55@yahoo.com.