Bias in observational study designs: cross sectional studies.
Institute for Medical and Biomedical Education, St George's, University of London, London, UK p.sedgwick@sgul.ac.uk.
Philip
P
Sedgwick
D015982:Bias; D003430:Cross-Sectional Studies; D006801:Humans; D064887:Observational Studies as Topic; D012107:Research Design