title: The choice of computational unit in the statistical analysis of unbalanced clinical trials.
abstract: Clinical periodontal research often involves the treatment of patients who have disease at several sites in the mouth. Should the units of analysis be the patients, the sites, or a combination of both? These strategies are explored and a worked example given.
authors.affiliation: London School of Hygiene and Tropical Medicine, UK.
authors.forename: J
authors.initials: J
authors.lastname: Osborn
mesh_terms: D000704:Analysis of Variance; D002986:Clinical Trials as Topic; D006801:Humans; D010510:Periodontal Diseases / Q000628:therapy*; D011897:Random Allocation; D012107:Research Design; D013223:Statistics as Topic