title: Understanding Large Database Studies.
abstract: There are several problems unique to large data sets. Large amounts of biased data are still biased and clinical significance is not always the same as statistical significance. Large number of predictors of outcome can confound conclusions, but there are several ways to manage wide ranging data sets including matching, regression, propensity scores, and randomization.
authors.affiliation: The Rothman Institute, Philadelphia, PA.
authors.forename: Mitchell G
authors.initials: MG
authors.lastname: Maltenfort
mesh_terms: D016208:Databases, Factual; D066264:Datasets as Topic; D005544:Forecasting; D006801:Humans; D012107:Research Design; D015983:Selection Bias; D016896:Treatment Outcome