Essays in economic theory

This dissertation consists of two essays in Game Theory with Incomplete Information. The common theme of the essays pertains to the interpretation and origin of incomplete information in strategic situations. In the first essay, I study bargaining between a buyer and a seller when the buyer can invest in generating outside options at a cost, and the seller cannot observe his investment choice. I model the negotiation phase as an incentive compatible and ex-post individually rational direct mechanism, which maximizes a weighted average of the buyer's and seller's expected payoff. When the weight on the buyer is larger, trade happens with certainty, the price equals the seller’s cost, and the buyer does not invest in generating outside options. When the weight on the seller is larger, the optimal mechanism is a posted price mechanism at the worst outside option that the buyer could have, provided that the cost function of the buyer is decreasing in first order stochastic dominance. The probability of trade is strictly below 1, even if it would be socially efficient to trade. In the second essay, I propose a notion of Rationalizability, called Incomplete Preference Rationalizability, for games with incomplete preferences. Under an appropriate topological condition, the incomplete preference rationalizable set is non-empty and compact. I argue that incomplete orderings can be used to model incomplete information in strategic settings. Drawing on this connection, I show that in games with private values the sets of incomplete preference rationalizable actions, of belief-free rationalizable actions (Battigalli et al., 2011, Bergemann and Morris, 2017), and of interim correlated rationalizable actions (Dekel et al., 2007) of the universal type space coincide

Usefulness of High-Sensitivity Troponin I in Risk Stratification and Final Disposition of Patients with Acute Heart Failure in the Emergency Department: Comparison between HFpEF vs. HFrEF

Background and Objectives: In patients with acute heart failure (AHF), there is no definite evidence on the relationship between high-sensitivity cardiac troponin (hs-cTnI) and the left ventricular ejection fraction (LVEF) comparing the reduced and preserved EF conditions. Materials and Methods: Between January and April 2022, we retrospectively analyzed the data from 386 patients admitted to the emergency departments (ED) of five hospitals in Rome, Italy, for AHF. The criteria for inclusion were a final diagnosis of AHF; a cardiac ultrasound and hs-cTnI evaluations in the ED; and age > 18 yrs. We excluded patients with acute coronary syndrome (ACS). Based on echocardiography and hs-cTnI evaluations, the patients were grouped for (1) preserved (HFpEF) or (2) reduced LVEF (HFrEF) and a a) negative (within the normal range value) or b) positive (above the normal range value) of hs-cTnI, respectively. Results: There was a significant negative relationship between a positive test for hs-cTnI and LVEF. When compared to the group with a negative hs-cTnI test, the patients with a positive test, both from the HFpEF and HFrEF subgroups, were significantly more likely to have an adverse outcome, such as being admitted to the intensive care unit (ICU) or dying in the ED. Moreover, a reduced ejection fraction was linked with a final disposition to a higher level of care. Conclusions: In patients admitted to the ED for AHF without ACS, there is a negative relationship between hs-cTnI and a reduced LVEF, although a significant percentage of patients with a preserved LVEF also resulted to have high levels of hs-cTnI. In the absence of ACS, hs-cTnI seems to be a reliable biomarker of myocardial injury in AHF in the ED and should be considered as a risk stratification parameter for these subjects regardless of the left ventricular function. Further larger prospective studies are needed to confirm these preliminary data

Implementation of the ERAS (Enhanced Recovery after Surgery) protocol for colorectal cancer surgery in the Piemonte Region with an Audit and Feedback approach: Study protocol for a stepped wedge cluster randomised trial: A study of the EASY-NET project

Introduction The ERAS protocol (Enhanced Recovery After Surgery) is a multimodal pathway aimed to reduce surgical stress and to allow a rapid postoperative recovery. Application of the ERAS protocol to colorectal cancer surgery has been limited to a minority of hospitals in Italy. To promote the systematic adoption of ERAS in the entire regional hospital network in Piemonte an Audit and Feedback approach (A&F) has been adopted together with a cluster randomised trial to estimate the true impact of the protocol on a large, unselected population. Methods A multicentre stepped wedge cluster randomised trial is designed for comparison between standard perioperative management and the management according to the ERAS protocol. The primary outcome is the length of hospital stay (LOS). Secondary outcomes are: incidence of postoperative complications, time to patients' recovery, control of pain and patients' satisfaction. With an A&F approach the adherence to the ERAS items is monitored through a dedicated area in the study web site. The study includes 28 surgical centres, stratified by activity volume and randomly divided into four groups. Each group is randomly assigned to a different activation period of the ERAS protocol. There are four activation periods, one every 3 months. However, the planned calendar and the total duration of the study have been extended by 6 months due to the COVID-19 pandemic. The expected sample size of about 2200 patients has a high statistical power (98%) to detect a reduction of LOS of 1 day and to estimate clinically meaningful changes in the other endpoints. Ethics and dissemination The study protocol has been approved by the Ethical Committee of the coordinating centre and by all participating centres. Study results will be timely circulated within the hospital network and published in peer-reviewed journals. Trial registration number NCT04037787

sj-pdf-1-eso-10.1177_23969873231186863 – Supplemental material for Anticoagulation in acute ischemic stroke patients with mechanical heart valves: To bridge or not with heparin. The ESTREM study

Supplemental material, sj-pdf-1-eso-10.1177_23969873231186863 for Anticoagulation in acute ischemic stroke patients with mechanical heart valves: To bridge or not with heparin. The ESTREM study by Maurizio Paciaroni, Valeria Caso, Michele Romoli, Cecilia Becattini, Alexander Salerno, Costanza Rapillo, Fanny Simonnet, Davide Strambo, Isabella Canavero, Marialuisa Zedde, Rosario Pascarella, Sung-Il Sohn, Simona Sacco, Raffaele Ornello, Kristian Barlinn, Daniela Schoene, Jan Rahmig, Maria Giulia Mosconi, Ilaria Leone De Magistris, Andrea Alberti, Michele Venti, Giorgio Silvestrelli, Alfonso Ciccone, Marina Padroni, Michele Laudisi, Andrea Zini, Luana Gentile, Odysseas Kargiotis, Georgios Tsivgoulis, Rossana Tassi, Francesca Guideri, Maurizio Acampa, Luca Masotti, Elisa Grifoni, Alessandro Rocco, Marina Diomedi, Theodore Karapanayiotides, Stefan T Engelter, Alexandros A Polymeris, Annaelle Zietz, Fabio Bandini, Pietro Caliandro, Giuseppe Reale, Marco Moci, Aurelia Zauli, Manuel Cappellari, Andrea Emiliani, Antonio Gasparro, Valeria Terruso, Marina Mannino, Elisa Giorli, Danilo Toni, Marco Andrighetti, Anne Falcou, Lina Palaiodimou, George Ntaios, Dimitrios Sagris, Efstathia Karagkiozi, Anastasia Adamou, Panagiotis Halvatsiotis, Yuriy Flomin, Umberto Scoditti, Antonio Genovese, Nemanja Popovic, Leonardo Pantoni, Francesco Mele, Nicola Molitierno, Piergiorgio Lochner, Alessandro Pezzini, Massimo Del Sette, Davide Sassos, Sotirios Giannopoulos, Maria Kosmidou, Evangelos Ntais, Enrico Maria Lotti, Vincenzo Mastrangelo, Alberto Chiti, Andrea Naldi, Peter Vanacker, Mario Ferrante, Vera Volodina, Michelangelo Mancuso, Nicola Giannini, Marco Baldini, Kostantinos Vadikolias, Sofia Kitmeridou, Carlo Emanuele Saggese, Tiziana Tassinari, Valentina Saia and Patrik Michel in European Stroke Journal</p