COMPERA 2.0. a refined four-stratum risk assessment model for pulmonary arterial hypertension

Background: Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a 3-strata model to categorise risk as low, intermediate, or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on 4 risk categories with intermediate risk subdivided into intermediate-low and intermediate-high risk. Methods: We analysed data from COMPERA, a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on functional class (FC), 6 min walking distance (6 MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal fragment of pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed with Kaplan-Meier analyses, log-rank testing, and Cox proportional hazards models. Results: Data from 1,655 patients with PAH were analysed. Using the 3-strata model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined 4-strata risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the 3-strata model and in 49.2% with the 4-strata model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk. Conclusions: Modified risk stratification using a 4-strata model based on refined cut-off levels for FC, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original 3-strata model

Decision processes of a suicide bomber : integrating economics and psychology

This paper provides a theoretical analysis regarding the rationality of suicide attacks from an economist’s point of view. It is argued that although a terrorist gives up future utility from consumption by committing a suicide attack, this loss can be overcompensated by the utility he derives from the attack. Some individual cases of suicide bombers are presented in order to elucidate the diversity of motivations behind the attacks. We derive conditions under which a rational agent might decide to become a suicide bomber – or to announce the attack and defect later. The paper shows why the decision to commit a suicide attack can be time-inconsistent and what mechanisms might prevent time-inconsistency. Integrating the psychological concepts of cognitive dissonance and terror management theory into our economic analysis, we demonstrate why – although predicted by standard economic theory – defection is a phenomenon rarely observed. We finally present some policy implications. In the light of our analysis, policies that focus on material well-being seem less promising than policies that address non-monetary benefits of suicide attacks. The paper concentrates on two policy strategies: offering alternatives – with respect to the aims of terrorism as well as the means to attain them – and reducing the information bias – with respect to the availability as well as the access to information