title: Comments on a commentary: statistical evaluation of split mouth caries trials.
abstract: When results of split mouth caries trials are reported, the most frequently used outcome measures are "effectiveness" and "net gain". In a recent review by Riordan & FitzGerald (Community Dent Oral Epidemiol 1994;22:192-7) of the statistical analysis of data from such trials, the close connection between effectiveness and the traditional epidemiological outcome measure, relative risk, was pointed out and the latter measure was recommended. The confidence intervals for these parameters were, however, incorrect. This note provides valid confidence intervals for net gain, effectiveness and relative risk based on data from split mouth trials and presents examples of the calculations.
authors.affiliation: Department of Biostatistics, Faculty of Health Sciences, University of Aarhus, Denmark. vaeth@biostat.aau.dk
authors.forename: M
authors.initials: M
authors.lastname: Vaeth
authors.forename: S
authors.initials: S
authors.lastname: Poulsen
mesh_terms: D016001:Confidence Intervals; D015986:Confounding Factors, Epidemiologic; D018849:Controlled Clinical Trials as Topic / Q000379:methods* / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D018865:Dental Research / Q000379:methods*; D006801:Humans; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D010895:Pit and Fissure Sealants / Q000627:therapeutic use; D012306:Risk
chemical_list: D010895:Pit and Fissure Sealants