title: Design and analytic concepts for periodontal clinical trials.
abstract: Aspects of the design and analysis of periodontal clinical trials are surveyed from a biostatistical perspective. Design issues discussed include protocol preparation, subject selection and its documentation, randomization, problems associated with the sample versus population paradigm in sampling of microbes and gingival fluid constituents, quality control, cross-over and split-mouth versus parallel-arm designs, blinding, and multicenter trials. Analytic discussion deals with the definition and choice of analytic unit, appropriate methods for the analysis of data from multiple sites within the same subject, the nature and application of randomization tests, interim analyses, subgroup analyses, and multiple comparison issues. Examples are provided to illustrate the feasibility of analyzing site-specific data while accounting for intra-subject correlation, which represents the increased similarity of sites chosen from the same mouth as compared to sites from different patients.
authors: Task Force on Design and Analysis, Inc., Lawrenceville, NJ.
authors: P B
authors: PB
authors: Imrey
authors: N W
authors: NW
authors: Chilton
mesh_terms: D016009:Chi-Square Distribution; D002986:Clinical Trials as Topic / Q000379:methods* / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D004311:Double-Blind Method; D006801:Humans; D016018:Least-Squares Analysis; D008828:Microbiological Techniques; D015337:Multicenter Studies as Topic / Q000379:methods; D010361:Patients; D010510:Periodontal Diseases / Q000628:therapy*; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic / Q000379:methods; D015203:Reproducibility of Results; D012107:Research Design; D012494:Sampling Studies; D016037:Single-Blind Method