title: Estimation of optimal dynamic anticoagulation regimes from observational data: a regret-based approach.
abstract: A complication of long-term anticoagulation is that the optimal dose level varies not only between patients but over time within patients, in response to short-term changes in lifestyle. Consequently, doseage needs to be adaptive but there are as yet no accepted decision rules. Since anticoagulant use is increasing worldwide there is a need for more objective and routine procedures. In this paper, we describe an analysis of observational longitudinal anticoagulant data, aimed at determining an optimal reactive dose-changing strategy. We use the regret parameterization approach advocated by Murphy (J. R. Stat. Soc. Ser. B 2003; 65:331-366). Practical problems encountered in the implementation of the approach are discussed and illustrated.
authors.affiliation: Department of Biostatistics, University of Copenhagen, Denmark. sr@biostat.ku.dk
authors.forename: Susanne
authors.initials: S
authors.lastname: Rosthøj
authors.forename: Catherine
authors.initials: C
authors.lastname: Fullwood
authors.forename: Robin
authors.initials: R
authors.lastname: Henderson
authors.forename: Syd
authors.initials: S
authors.lastname: Stewart
mesh_terms: D000465:Algorithms; D000925:Anticoagulants / Q000008:administration & dosage*; D001778:Blood Coagulation Disorders / Q000188:drug therapy*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D011517:Prothrombin Time; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D014859:Warfarin