title: Comparison of selection procedures for the formation of homogeneous groups in clinical tests of dental care agents.
abstract: Synopsis Dental trials of new dental care formulations are studied with regard to specific quality characteristics such as inhibition of plaque formation and reduction of gingival bleeding, and require homogeneous panels of test persons in which both systematic and random sources of experimental error are excluded. The homogeneous panels must be formed from an available pool of test persons (global panel) so that each panel as a subset presents the same dental features on average and can be compared statistically one with another. This is a necessary condition for a valid scientific conclusion to be obtained from comparative dental studies. This type of homogeneous group division of a global panel can clearly be based on other medical features. Four selection procedures for the formation of homogeneous panels from the global panel were compared quantitatively with regard to their efficiency and homogeneity of group division, namely: - randomization method; - block target method; - median pair method; - block median pair method. With the exception of the randomization method, which can be applied more generally, the other selection methods require a preliminary study of the available test persons with regard to their medical features. A comparison of the four selection procedures shows that the three other methods are more likely to provide more homogeneous panels than the randomization method. Comparaison des procedures de selection concernant la formation de groupes homogènes dans les tests cliniques des agents de soins dentaires.
authors.affiliation: Henkel KGaA, Postbox 11 00, D-4000 Düsseldorf 1, Federal Republic of Germany.
authors.forename: E
authors.initials: E
authors.lastname: Bill
authors.forename: H J
authors.initials: HJ
authors.lastname: Klueppel