title: Hierarchical modeling: its time has come.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: DeLong
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods; D016000:Cluster Analysis; D016001:Confidence Intervals; D015233:Models, Statistical; D011785:Quality Assurance, Health Care / Q000379:methods; D012044:Regression Analysis; D012107:Research Design; D016896:Treatment Outcome