Conceptos y herramientas para transitar hacia la sostenibilidad : avances a 2020

En este contexto institucional, desde las líneas de investigación de sostenibilidad en paisajes urbano-rurales, gestión ambiental sectorial y conflictos socioecológicos, los autores de esta publicación se plantearon el reto de generar una serie de documentos denominada “Conceptos y herramientas para transitar hacia la sostenibilidad” que recoja el conocimiento y la experiencia del Instituto entorno a los cambios transformacionales necesarios a nivel nacional para lograr el establecimiento de unos sistemas socioecológicos sostenibles en el país. En el caso de este primer documento de la serie, se busca recoger los avances conceptuales y las herramientas generadas por el Instituto hasta 2020 para apalancar TSS planteadas.Bogotá D.C

Escenarios prospectivos de sostenibilidad en la cooperación entre comunidades rurales: análisis de bifurcaciones y sistemas de Filippov

En el contexto de la sostenibilidad de sistemas socio-ecológicos existe una creciente comunidad académica estudiando las relaciones que definen este tipo de sistemas y las herramientas para cualificarlos y cuantificarlos. Desde el modelamiento matemático, los sistemas dinámicos son una alternativa para desarrollar estas herramientas. En esta tesis se proponen diferentes modelos matemáticos desde una construcción sistémica, y se analizan sus implicaciones dinámicas a partir de la teoría de bifurcaciones y el mapeo de Poicare, con el propósito de evaluar la sensibilidad de los sistemas ante cambios en los valores de los parámetros y entender todos los escenarios de sostenibilidad en diferentes planos paramétricos. Este análisis se propone como una metodología para evaluar la sostenibilidad de sistemas socio-ecológicos a partir del estado estacionario de los mismos. Los modelos propuestos consideran la interacción dinámica entre la población y el uso que le dan a sus recursos renovables desde tres temas principales: el comportamiento de comunidades aisladas en las que no existe interacción con actores externos, el rol del intercambio comercial (continuo y discontinuo) entre dos comunidades y como este intercambio cambia los escenarios de sostenibilidad de las comunidades involucradas. Los resultados indican que los diagramas de bifurcaciones permiten entender el cambio que sufren los escenarios de sostenibilidad cuando se cambian uno o dos parámetros simultáneamente, lo que permite proponer medidas de sostenibilidad basadas en las propiedades dinámicas del sistemaAbstract In the context of the sustainability of socioecological systems there is a growing academic community studying the relationships that define this type of systems and the tools to qualify and quantify them. From mathematical modeling, Dynamical Systems Theory is an alternative to develop these tools. This thesis proposes different mathematical models from a systemic construction, and its dynamic implications are analyzed from the bifurcation theory and the Poincare mapping, with the purpose of evaluating the sensitivity of the systems to changes in the values of the parameters and understand all sustainability scenarios in different parameters. This analysis is proposed as a methodology to evaluate the sustainability of socioecological systems from the steady state of the same. The proposed models consider the dynamic interaction between the population and the use they give their renewable resources from three main themes: the behavior of isolated communities in which there is no interaction with external actors, the role of commercial exchange (continuous and discontinuous) between two communities and how this exchange changes the sustainability vii scenarios of the communities involved. The results indicate that the bifurcation diagrams allow to understand the change suffered by the sustainability scenarios when one or two parameters are changed simultaneously, which allows proposing sustainability measures based on the dynamic properties of the systemDoctorad

Non-Linear and Non-Smooth dynamics study in sustainable development systems

El eje temático de este trabajo es estudiar la interacción dinámica a largo plazo entre la explotación de recursos naturales y el crecimiento de la población en una sociedad que depende económicamente de la agricultura y los recursos naturales. Se presentan diferentes modelos de desarrollo y se analizan utilizando teoría de bifurcaciones y simulaciones en el espacio de estados con el objetivo de encontrar valores de los parámetros que permitan un comportamiento a largo plazo ya sea con la extinción de los recursos o con valores positivos de estos. Las simulaciones muestran que los sistemas dependen fuertemente de los parámetros tecnológicos y sociales los cuales inducen diferentes tipos de bifurcaciones. Hopf, silla-nodo, puntos de bifurcación de codimension dos, comportamiento caótico, y bifurcaciones de ciclos limite aparecieron en los sistemas. Fenómenos no suaves como deslizamiento y pseudo equilibrios fueron obtenidos cuando una reserva de recursos renovables es protegida de la explotación humana. Para un escenario sostenible se concluyó que se deben introducir al sistema varias acciones de sostenibilidad con el objetivo de permanecer en los equilibrios no triviales o en un comportamiento oscilatorio / Abstract: The central thematic of this work is the study of the long-run dynamic interaction between the exploitation of natural resources and population growth in a society that is economically dependant on renewable resources and agriculture. Different mathematical models of development are presented and analysed through bifurcation theory and state space simulations in order to obtain parameter settings that yield positive values of resources and population in the long-run and parameter settings in which resources become extinct. Simulations show that systems are highly dependant on social and technological parameters which induce different types of bifurcations. Hopf, saddle-node, codimension-two bifurcations points, chaotic behaviour, and bifurcation of limit cycles appeared in the systems. Non-smooth phenomena such as sliding and pseudo equilibrium are also present when a reserve of renewable resources is protected from human exploitation. Analysis conclude that for a sustainable scheme, several sustainability actions must be introduced in the system in order to keep non-trivial equilibrium or stationary oscillations among the dimensions.Maestrí

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research