title: Reduction in burden of illness: a new efficacy measure for prevention trials.
abstract: A new efficacy measure is developed for use in prevention trials of interventions which may affect both disease incidence and disease severity. We assign a severity score to each incident case and sum severity scores over all incident cases within each treatment group to create a burden-of-illness score for each treatment group. Efficacy is evaluated by the difference between the burden-of-illness per randomized subject in the two randomized treatment groups. Since the numbers of summands in each burden-of-illness score is a random variable, standard methods of analysis are not directly applicable. The asymptotic distribution and sampling properties of the net reduction in the burden-of-illness score are derived for trials designed to stop either after a fixed length of follow-up or after the occurrence of a fixed number of cases. We illustrate the method with data from a clinical trial of a human rotavirus vaccine.
authors.affiliation: Department of Statistics, University of Florida, Gainesville 32611.
authors.forename: M N
authors.initials: MN
authors.lastname: Chang
authors.forename: H A
authors.initials: HA
authors.lastname: Guess
authors.forename: J F
authors.initials: JF
authors.lastname: Heyse
mesh_terms: D003627:Data Interpretation, Statistical; D003967:Diarrhea / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D015233:Models, Statistical; D011322:Primary Prevention / Q000706:statistics & numerical data*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D012400:Rotavirus Infections / Q000453:epidemiology / Q000517:prevention & control; D018401:Sample Size; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014765:Viral Vaccines
chemical_list: D014765:Viral Vaccines