title: Sample calculations for comparing rates.
authors.affiliation: Statistics and Research Design, Bern, Switzerland.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Pandis
authors.forename: David
authors.initials: D
authors.lastname: Machin
mesh_terms: D000465:Algorithms; D003627:Data Interpretation, Statistical; D018865:Dental Research / Q000706:statistics & numerical data*; D004868:Equipment Failure / Q000706:statistics & numerical data; D006801:Humans; D016910:Orthodontic Brackets / Q000706:statistics & numerical data; D018570:Risk Assessment; D018401:Sample Size; D016019:Survival Analysis