Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Household activities through various lenses: crossing surveys, diaries and electric consumption

The analysis of household energy consumption usually involves the description of technical systems and of people behaviors. This work focuses on the relationship between people activities, appliances use, and electric consumption. It relies on the application of a wide range of measurement tools on a unique sample of 60 households in France. Overall, questionnaires, diaries, and measured consumption provided a consistent description of the intensity and time of use of the three appliances studied. However, variations were found, depending on the indicator and appliance studied. The levels of activity derived from the diaries and consumption show large differences. However, they can be explained based on reasonable assumptions on the differences in the nature of the activities. Most importantly the variations in the intensity of use across households are consistent among the three measurement tools. This result allowed a partial description of the role of the frequency and duration of use, appliances features and energy saving gestures in the final energy consumption. In terms of methodology, this study shows that, questionnaires can provide consistent information on the relative level of energy consumption by household, while diaries provide reliable information about when this energy is consumed, supporting the use of the large scale and wide spread “Time Use Surveys” to model the diversity of power demand in Europe and America

Household activities through various lenses: crossing surveys, diaries and electric consumption

The analysis of household energy consumption usually involves the description of technical systems and of people behaviors. This work focuses on the relationship between people activities, appliances use, and electric consumption. It relies on the application of a wide range of measurement tools on a unique sample of 60 households in France. Overall, questionnaires, diaries, and measured consumption provided a consistent description of the intensity and time of use of the three appliances studied. However, variations were found, depending on the indicator and appliance studied. The levels of activity derived from the diaries and consumption show large differences. However, they can be explained based on reasonable assumptions on the differences in the nature of the activities. Most importantly the variations in the intensity of use across households are consistent among the three measurement tools. This result allowed a partial description of the role of the frequency and duration of use, appliances features and energy saving gestures in the final energy consumption. In terms of methodology, this study shows that, questionnaires can provide consistent information on the relative level of energy consumption by household, while diaries provide reliable information about when this energy is consumed, supporting the use of the large scale and wide spread “Time Use Surveys” to model the diversity of power demand in Europe and America

Spatial location of activities and energy consumption of households in France

The design of policies and interventions aiming at the reduction of energy consumption requires a good understanding of the underlying social logics. In this perspective, this paper focuses on how the distribution of daily activities at home and away, in various locations, result into different levels of energy consumption in buildings and transportation. This analysis is based on an ad hoc survey of 2000 French households in late 2013. The questionnaire was focused on daily activities, mobility and energy consumption. This core information was complemented with questions about values, residential location and equipment choices. Additional information was collected regarding building types, appliances and socio-demographics. We also did a socio-spatial description of the geographical areas, based on several databases from the French statistical office (INSEE). Our initial analysis consists in clustering respondents based on their stated daily activities and values, in an attempt to qualify distinct lifestyles. Short- and long-term choices at the individual and household level were considered in this task. We then described how these lifestyles and how they deploy in space, imply the use of different types and levels of energy consumption