Study on the concentration, distribution, and persistence of health spending for the contributory scheme in Colombia.

Colombia is among the countries with the most robust financial protection against personal health spending in the world, with out-of-pocket spending ranking lowest across OECD countries. We investigate the evolution, distribution, and persistence of health spending by age group, sex, health care setting, health condition and geographic region for over 19 million users of Colombia's health system between 2013 and 2021 (contributory scheme). We use average patient-level expenditure data from the Health-Promoting Entities of the Ministry of Health and Social Protection. We applied multivariate statistical techniques such as multiple correspondence analysis, factor maps and correlations. For both sexes, average health expenditure increases gradually with age until 60 years, accelerating thereafter abruptly. Health conditions with the highest percentage of expenditure were those related to neoplasms, blood diseases, circulatory system, pregnancy, puerperium and perinatal period. We found that home-based care in Amazonía-Orinoquía is almost non-existent, and that outpatient care represents a high proportion in all age groups (over 65%) compared to the other regions. There is a strong persistence of expenditure from one year to the next (i.e. they can provide relevant information for prediction), especially in areas with a larger supply of health services such as Bogotá-Cundinamarca. To the authors' knowledge, this is the most comprehensive and detailed micro-analysis of health spending that has been developed for a Latin American country to date.

Use of Cost-Effectiveness Thresholds in Healthcare Public Policy: Progress and Challenges.

The article offers a comparative analysis of the influence of cost-effectiveness thresholds in the decision-making processes in financing policies, coverage, and price regulation of health technologies in nine countries. We investigated whether countries used cost-effectiveness thresholds for public health policy decision making and found that few countries have adopted the cost-effectiveness threshold as an official criterion for financing, reimbursement, or pricing. However, in countries where it is applied, such as Thailand, the results have been very favorable in terms of minimizing health technology prices and ensuring the financial sustainability of the health system. Although the cost-effectiveness threshold has opportunities for improvement, particularly in certain institutional contexts and with adequate participation of the different strategic actors in the formulation of public policy, its potential use and added value are significant in various aspects.

The effect of the exit of an insurer, due to government liquidation, on access to health care: evidence from Colombia.

Our study evaluates the liquidation effect of a health insurer from a subsidized scheme, with the largest number of members in Colombia, on restrictions to future access to user care. Based on the information regarding complaints and judicial claims about healthcare, the effect of this government decision is estimated using a dynamic econometric model of differences in differences. Our results suggest that the liquidation of the Health-Promoting Entity (EPS, its acronym in Spanish) CAPRECOM has a negative effect, specifically, it led to an increase of 0.32 and 0.21 in complaints rates per 1,000 members in the receiving EPSs during the first and second quarters after the intervention, respectively. However, this effect does not persist over time and becomes diluted in the following quarters. There is no evidence of a relationship between the magnitude of the effect and the EPSs performance ranking. Additionally, we do not find significant effects on judicial claims. Our results are important concerning the design and implementation of public policies for EPSs liquidation. We demonstrate the necessity of implementing actions to incorporate guidelines and strategic plans during the transition period. Such actions would enable safeguarding the right to health for the affected population in a liquidation insurer case.

Science, technology, and innovation in health for the next twenty years: A survey analysis in Colombia.

Background: Colombia is a Latin American country with a very complex social and political context that has not allowed the allocation of sufficient resources to the fields of science, technology, and innovation (STI). This is particularly worrying for the area of health since not enough resources are allocated for public health, research, or education. Methods: The so-called "Great Survey in Health 2019" was administered online through the SurveyMonkey platform to 5298 people in different regions of the country, representing the public, private, and academic sectors. The questionnaire consisted of 46 open and closed questions, including demographic inquiries. Data analysis involved textual analytics and sentiment analysis. Results: Overall, 56% of those surveyed were women within the adult life cycle. Most respondents had a postgraduate education. Greater participation was observed in the Oriental, Bogotá, and Antioquia regions, which also concentrate the largest number of resources for STI. Among the main recommendations derived from the results, priorities include investing in research, personalised medicine, promoting the social appropriation of knowledge, addressing mental health, regulating research through a statute, promoting undergraduate research, and establishing recertification exams to pursue excellence. Conclusion: The results of this original study serve as a fundamental input to promote and strengthen the STI processes in life sciences and health. They serve as a guide to generate public policies and actions that guarantee better health and well-being for the Colombian population, strategically proposing a clear roadmap for the next 20 years.

Which health conditions report the most spending on medical imaging? Evidence for Colombia.

Medical imaging is essential for the proper diagnosis and treatment of many diseases. The literature has found that medical imaging generally accounts for a significant percentage of total healthcare spending. We analyzed a national database between 2013 and 2021, with more than 19 million patients on average, to review which health conditions account for the highest spending on medical imaging in the Colombian health system. We segmented the analysis by type of medical imaging, life cycles, health condition and sex. Our findings indicate that cardiac and mental illnesses account for the highest per capita spending on medical imaging, especially for the elderly. As a proportion of total expenditure, hypertension and tuberculosis are added, with special emphasis on the infancy-childhood life cycle.

The value of mathematical modelling approaches in epidemiology for public health decisión making

It is discussed the relevance of quantitative approaches, specifically mathematical modelling in epidemiology, in the public health decision-making process. This topic is discussed here based on the experience of various experts in mathematical epidemiology and public health. First, the definition of mathematical modelling is presented, especially in the context of epidemiology. Second, the different uses and socio-political implications, including empirical examples of recent experiences that have taken place at the international level are addressed. Finally, some general considerations regarding the challenges encountered in the use and application of mathematical modelling in epidemiology in the decision-making process at the local and national levels.

Se trata sobre la importancia de los abordajes cuantitativos, específicamente la formulación de modelos matemáticos en epidemiología, dentro del proceso de toma de decisiones en salud pública. Esta importante temática se analiza basándose en la experiencia de algunos expertos en epidemiología matemática y salud pública. En primer lugar, se presenta la definición de modelación matemática, particularmente dentro del contexto de la epidemiología. En segundo lugar, se abordan los diferentes usos y las implicaciones socio-políticas, incluyendo ejemplos de experiencias recientes que han ocurrido a nivel internacional. Finalmente, se hace referencia a ciertas consideraciones generales respecto a los retos que representa el uso y la aplicación de modelos matemáticos en epidemiología para el proceso de toma de decisiones a nivel local y nacional.

Predictive models for health outcomes due to SARS-CoV-2, including the effect of vaccination: a systematic review.

BACKGROUND: The interaction between modelers and policymakers is becoming more common due to the increase in computing speed seen in recent decades. The recent pandemic caused by the SARS-CoV-2 virus was no exception. Thus, this study aims to identify and assess epidemiological mathematical models of SARS-CoV-2 applied to real-world data, including immunization for coronavirus 2019 (COVID-19). METHODOLOGY: PubMed, JSTOR, medRxiv, LILACS, EconLit, and other databases were searched for studies employing epidemiological mathematical models of SARS-CoV-2 applied to real-world data. We summarized the information qualitatively, and each article included was assessed for bias risk using the Joanna Briggs Institute (JBI) and PROBAST checklist tool. The PROSPERO registration number is CRD42022344542. FINDINGS: In total, 5646 articles were retrieved, of which 411 were included. Most of the information was published in 2021. The countries with the highest number of studies were the United States, Canada, China, and the United Kingdom; no studies were found in low-income countries. The SEIR model (susceptible, exposed, infectious, and recovered) was the most frequently used approach, followed by agent-based modeling. Moreover, the most commonly used software were R, Matlab, and Python, with the most recurring health outcomes being death and recovery. According to the JBI assessment, 61.4% of articles were considered to have a low risk of bias. INTERPRETATION: The utilization of mathematical models increased following the onset of the SARS-CoV-2 pandemic. Stakeholders have begun to incorporate these analytical tools more extensively into public policy, enabling the construction of various scenarios for public health. This contribution adds value to informed decision-making. Therefore, understanding their advancements, strengths, and limitations is essential.

Internet of Things and citizen science as alternative water quality monitoring approaches and the importance of effective water quality communication.

The increasing demand for water and worsening climate change place significant pressure on this vital resource, making its preservation a global priority. Water quality monitoring programs are essential for effectively managing this resource. Current programs rely on traditional monitoring approaches, leading to limitations such as low spatiotemporal resolution and high operational costs. Despite the adoption of novel monitoring approaches that enable better data resolution, the public's comprehension of water quality matters remains low, primarily due to communication process deficiencies. This study explores the advantages and challenges of using Internet of Things (IoT) and citizen science as alternative monitoring approaches, emphasizing the need for enhancing public communication of water quality data. Through a systematic review of studies implemented on-field, we identify and propose strategies to address five key challenges that IoT and citizen science monitoring approaches must overcome to mature into robust sources of water quality information. Additionally, we highlight three fundamental problems affecting the water quality communication process and outline strategies to convey this topic effectively to the public.

Loss ratio of the capitation payment unit of the health-promoting entities in Colombia between 2017 and 2021: a financial-actuarial approach.

BACKGROUND: Because of a change of government, the Colombian Ministry of Health and Social Protection is in the process of presenting a structural reform for the General System of Social Security in Health (GSSSH), in order to implement a 'preventive and predictive health model'. However, it will always be relevant to review and analyze the fiscal implications of any proposed public policy program, to protect financial sustainability and to promote the better functioning of the system in question. METHODS: To contribute to this topic, we have calculated, using a financial-actuarial approach, the loss ratio for the years 2017 to 2021 for the Capitation Payment Unit (CPU) for all the Health-Promoting Entities (HPE) for both contributory and subsidized schemes. This information, derived from public reports available on the official website of the National Health Superintendency, allows us to estimate the financial burden of the institutions that guarantee access to and provision of health services and technologies in Colombia. RESULTS: The study shows that close to half of the HPEs in Colombia (which represent 11.6 million affiliates) have CPU loss ratios of more than 100% for the year 2021, evidencing insufficient resources for the operation of health insurance. CONCLUSIONS: Finally, we propose some policy recommendations regarding the strengthening of informed decision-making to allow the healthy financial sustainability of the Colombian GSSSH.

Detecting unexpected growths in health technologies expenditures: the case of MIPRES in Colombia.

We developed an algorithm to explore unexpected growth in the usage and costs of health technologies. We exploit data from the expenditures on technologies funded by the Colombian government under the compulsory insurance system, where all prescriptions for technologies not included in an explicit list must be registered in a centralized information system, covering the period from 2017 to 2022. The algorithm consists of two steps: an outlier detection method based on the density of the expenditures for selecting a first set of technologies to consider (39 technologies out of 106,957), and two anomaly detection models for time series to determine which insurance companies, health providers, and regions have the most notorious increases. We have found that most medicines associated with atypical behavior and significant monetary growth could be linked to the use of recently introduced drugs in the market. These drugs have valid patents and very specific clinical indications, often involving high-cost pharmacological treatments. The most relevant case is the Burosumab, approved in 2018 to treat a rare genetic disorder affecting skeletal growth. Secondly, there is clear evidence of anomalous increasing trend evolutions in the identified enteral nutritional support supplements or Food for Special Medical Purposes. The health system did not purchase these products before July 2021, but in 2022 they represented more than 500,000 USD per month.

Years of life lost to COVID-19 in 49 countries: A gender- and life cycle-based analysis of the first two years of the pandemic.

Specific mortality rates have been widely used to monitor the main impacts of the COVID-19 pandemic; however, a more meaningful measure is the Years of Life Lost (YLL) due to the disease, considering it takes into account the premature nature of each death. We estimated the YLL due to COVID-19 between January 2020 and December 2021 in 49 countries for which information was available, developing an analytical method that mathematically refines that proposed by the World Health Organization. We then calculated YLL rates overall, as well as by sex and life cycle. Additionally, we estimated the national cost-effective budgets required to manage COVID-19 from a health system perspective. During the two years of analysis, we estimated that 85.6 million years of life were lost due to COVID-19 in the 49 countries studied. However, due to a lack of data, we were unable to analyze the burden of COVID-19 in about 75% of the countries in the world. We found no difference in the magnitude of YLL rates by gender but did find differences according to life cycle, with older adults contributing the greatest burden of YLL. The COVID-19 pandemic has posed a significant burden of disease, which has varied between countries. However, due to the lack of quality and disaggregated data, it has been difficult to monitor and compare the pandemic internationally. Therefore, it is imperative to strengthen health information systems in order to prepare for future pandemics as well as to evaluate their impacts.

Characterization of the population affiliated to the subsidized health insurance scheme in Colombia: a systematic review and meta-analysis.

BACKGROUND: Some reports suggest there are differences in health needs between the population affiliated to the subsidized health insurance scheme (SS) and those affiliated to the contributory health insurance scheme (CS) in Colombia. The objective of this study was to identify the epidemiological profile of the population affiliated to the SS in Colombia and to compare the main epidemiological features of the SS to the CS. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) methodology, the search was carried out from 1993, with no other restriction. The information was synthesized into five categories according to the most important risk populations. We estimated combined incidences from epidemiological surveillance data, prevalence ratio, and other measures to estimate the difference between the studied groups. A 95% confidence interval was considered. A random effects model was used weighted by the inverse of the variance of the cumulative incidence calculated for each disease. The risk of bias was assessed using the Joanna Briggs Institute's critical appraisal tools. RESULTS: A total of 16,236 articles were identified; 14,972 were excluded after title and abstract screening, 725 articles were verified as full text, and finally 268 articles were included. The relative risk of non-communicable and communicable diseases was lower in the SS than in the CS (RR: 0.37 and 0.72, respectively, p-value < 0.05). However, the risk of presenting obstetric and maternal conditions in the SS versus the CS was RR 1.55 for frequent conditions during early childhood, and for other diseases it was RR 1.28 with a p-value of < 0.05. The use of health services was different by scheme, with less demand, access, and provision being found in health services in the SS. CONCLUSIONS: This study allowed us to conclude that there are differences in the incidence, prevalence, and use of health services between health affiliation schemes (SS and CS) in Colombia, thereby assisting in decision-making for stakeholders. TRIAL REGISTRATION: PROSPERO Registration number CRD42021279234.

Statistical actuarial estimation of the Capitation Payment Unit from copula functions and deep learning: historical comparability analysis for the Colombian health system, 2015-2021.

The Capitation Payment Unit (CPU) financing mechanism constitutes more than 70% of health spending in Colombia, with a budget allocation of close to 60 trillion Colombian pesos for the year 2022 (approximately 15.7 billion US dollars). This article estimates actuarially, using modern techniques, the CPU for the contributory regime of the General System of Social Security in Health in Colombia, and compares it with what is estimated by the Ministry of Health and Social Protection. Using freely available information systems, by means of statistical copulas functions and artificial neural networks, pure risk premiums are calculated between 2015 and 2021. The study concludes that the weights by risk category are systematically different, showing historical pure premiums surpluses in the group of 0-1 years and deficits (for the regions normal and cities) in the groups over 54 years of age.

[Epidemiological and clinical characteristics of the COVID-19 epidemic in Mexico: Quintana Roo case]. / Características epidemiológicas y clínicas de la epidemia COVID-19 en México: caso Quintana Roo.

Objective: Identify risk factors for severe outcome in Mexican patients with COVID-19 in the population of Quintana Roo. Material and methods: Study of 5,916 who met the criteria for suspected cases of COVID-19, 2,531 confirmed by qrTPCR-Sars-CoV-2 tests, of which 1,486 were positive, among which they were classified as hospitalized (severe COVID-19) and outpatients. Multivariate logistic regression analysis was performed to explore the factors associated with the severity of COVID-19 and death as clinical outcomes. The basic reproduction number (R0) was calculated Statistical analysis) Endorsement of the ethics committee 2301. Results: SARS-CoV-2 positive patients presented a high prevalence of hypertension 29.1%, diabetes 23.5%, obesity 24%, and 48.5% have at least one chronic disease. There is a high risk of severity for COVID-19 in patients with diabetes OR=3.14, hypertension OR=1.88, obesity OR=1.68, kidney disease OR=3.2, older than 65 years OR=13.6 and men OR=1.7. These factors also increase the risk of death up to 7.7 times. The maximum R0 during the epidemic was 2.4. Conclusion: Liver and kidney disease, diabetes, hypertension, and obesity are significantly associated with severe COVID-19 and death.

Objetivo: identificar factores de riesgo para desenlace a COVID-19 grave en pacientes mexicanos con de COVID-19 en población en Quintana Roo. Material y métodos: estudio de 5,916 quienes cumplieron criterios de casos sospechosos de COVID-19, 2,531 confirmados por pruebas qrTPCR-Sars-CoV-2 de los cuales 1,486 fueron positivos entre los cuales se clasifico en hosptializados (COVID-19 grave) y ambulatorios. Se realizó análisis de regresión logística multivariada para explorar los factores asociados con la gravedad de COVID-19 y defunción como desenlaces clínicos. Se calculó el número básico de reproducción (R0) Análisis estadístico) Aval del comité de ética 2301. Resultados: pacientes positivos a SARS-CoV-2 presentaron alta prevalencia de hipertensión 29.1%, diabetes 23.5%, obesidad 24%, y 48.5% tiene al menos una enfermedad crónica. Existe alto riesgo de severidad para COVID-19 en pacientes con diabetes OR=3.14; hipertensión OR=1.88, obesidad OR=1.68, enfermedad renal OR=3.2, mayores de 65 años OR=13.6 y hombres OR=1.7. Estos factores también incrementan el riesgo de defunción hasta 7.7 veces. El R0 máximo durante la epidemia fue de 2.4. Conclusión: la enfermedad hepática, renal, diabetes, hipertensión y obesidad se asocian significativamente a COVID-19 severo y defunción.

Cost-Effectiveness Analysis of Strategies of COVID-19 Vaccination in Colombia: Comparison of High-Risk Prioritization and No Prioritization Strategies With the Absence of a Vaccination Plan.

OBJECTIVES: Our study compares two national COVID-19 vaccination plan strategies-high-risk prioritization and no prioritization-and estimates their cost-effectiveness compared with no vaccination, to generate possible recommendations for future vaccination plans. METHODS: We developed a Markov discrete-time, compartmental, deterministic model stratified by Colombian departments, healthcare workers, comorbidities, and age groups and calibrated to seroprevalence, cases, and deaths. The model simulates three scenarios: no vaccination, no prioritization of vaccination, and prioritization of high-risk population. The study presents the perspective of the health system of Colombia, including the direct health costs financed by the government and the direct health outcomes related to the infection. We measured symptomatic cases, deaths, and costs for each of the three scenarios from the start of the vaccination rollout to February 20, 2023. RESULTS: Both for the base-case and across multiple sensitivity analyses, the high-risk prioritization proves to be the most cost-effective of the considered strategies. An increment of US$255 million results in an incremental cost-effectiveness ratio of US$3339 per disability-adjusted life-year avoided. The simulations show that prioritization of high-risk population reduces symptomatic cases by 3.4% and deaths by 20.1% compared with no vaccination. The no-prioritization strategy is still cost-effective, with an incremental cost-effectiveness ratio of US$5223.66, but the sensitivity analysis the show potential risks of losing cost-effectiveness under the cost-effectiveness threshold (one gross domestic product per averted disability-adjusted life-year). CONCLUSIONS: The high-risk prioritization strategy is consistently more cost-effective than the no-prioritization strategy across multiple scenarios. High-risk prioritization is the recommended strategy in low-resource settings to reduce the burden of disease.

Natural marine products as antiprotozoal agents against amitochondrial parasites.

The goal of this work is to compile and discuss molecules of marine origin reported in the scientific literature with anti-parasitic activity against Trichomonas, Giardia, and Entamoeba, parasites responsible for diseases that are major global health problems, and Microsporidial parasites as an emerging problem. The presented data correspond to metabolites with anti-parasitic activity in human beings that have been isolated by chromatographic techniques from marine sources and structurally elucidated by spectroscopic and spectrometric procedures. We also highlight some semi-synthetic derivatives that have been successful in enhancing the activity of original compounds. The biological oceanic reservoir offers the possibility to discover new biologically active molecules as lead compounds to develop new drug candidates. The molecular variety is extensive and must be correctly explored and managed. Also, it will be necessary to take some actions to preserve the source species from extinction or overharvest (e.g., by cryopreservation of coral spermatozoa, oocytes, embryos, and larvae) and coordinate appropriate exploitation to increase the chemical knowledge of the natural products generated in the oceans. Additional initiatives such as the total synthesis of complex natural products and their derivatives can help to prevent overharvest of the marine ecosystems and at the same time contribute to the discovery of new molecules.

NeuroImmunoEndocrinology: A brief historic narrative.

Although no precise moment or unique event marks its birth, neuroimmunoendocrinology arguably shares a great deal of history with other medical and biologic disciplines. It originated from empirical observations and suppositions that failed to prevail upon the existing axioms. Despite the widespread resistance to embracing novel ideas, the seeming defeats inspired visionary researchers. Those pioneers managed to systematize the emerging knowledge and were able to contribute to science with real foundations. In consequence, new concepts and ideas arose in physiology, anatomy, endocrinology and early immunology. Together, they gave rise to a budding approach on the integration between the nervous, immune and endocrine systems. Then, neuroimmunoendocrinology emerged as a discipline integrating an intricate system with multidirectional functions and interactions that allow for responding to internal and external threats. Such response is mediated by cytokines, hormones and neurotransmitters, involved in different physiologic mechanisms of the organism homeostasis. Neuroimmunoendocrinology is no longer an area of scientific skepticism; on the contrary, it has cemented its position as a biomedical discipline worldwide for the past 70 years. Now, it offers a better understanding of pathologic processes.

Estimating cost-effectiveness thresholds under a managed healthcare system: experiences from Colombia.

Like most of the world, low- and middle-income countries have faced a growing demand for new health technologies and higher budget constraints. It is necessary to have technical instruments to make decisions based on real-world evidence that allows maximization of the population's health with a limited budget. We estimated the supply-based cost-effectiveness elasticity, which was then used to determine the cost-effectiveness threshold for the healthcare system of Colombia, a middle-income country where multiple insurers, paid under capitation rules, manage the compulsory contributions of the citizens and government subsidies. Using administrative data, we explored the variation of health expenditures and outcomes at the insurer, geographical region, diagnosis group and year levels. To deal with endogeneity in a two-way fixed-effects model, we instrumented health expenditures using characteristics of the health system such as drug-price regulation. We estimated the threshold to be US$4487.5 per years of life lost avoided [14.7 million Colombian pesos (COP) at 2019 prices] and US$5180.8 per quality-adjusted life-years gained (17 million COP at 2019 prices), around one times the gross domestic product GDP per capita. To the best of our knowledge, this is the first estimation of the cost-effectiveness threshold elasticity supply-based in a middle-income country with a managed healthcare system.

Sera from patients with tuberculosis increase the phagocytic-microbicidal activity of human neutrophils, and ESAT-6 is implicated in the phenomenon.

Background: It has been reported that sera from patients with active pulmonary tuberculosis (APT) induced nuclear changes in normal neutrophils that included pyknosis, swelling, apoptosis, and production of extracellular traps (NETs). Similar changes were observed with some sera from their household contacts but not with sera from healthy, unrelated individuals. It was suggested that those sera from household contacts that induced neutrophil nuclear changes might correspond to people with subclinical tuberculosis. Thus, our experimental approach might serve to identify individuals with early, ongoing disease. Methods: Nuclear changes in neutrophils were fully evident by 3 h of contact and beyond. Circulating mycobacterial antigens were the most likely candidates for this effect. We wanted to know whether the nuclear changes induced on neutrophils by the sera of APT patients would negatively affect the phagocytic/microbicidal ability of neutrophils exposed to APT sera for short periods. Results: We now provide evidence that short-term contact (30 min) with sera from patients with pulmonary tuberculosis increases several phagocytic parameters of normal neutrophils, including endocytosis, myeloperoxidase levels, production of free reactive oxygen species, phagolysosome fusion, and microbicidal activity on Staphylococcus aureus, with these effects not being observed with sera from healthy donors. We also give evidence that suggests that ESAT-6 and CFP-10 are involved in the phenomenon. Conclusion: We conclude that activation is a stage that precedes lethal nuclear changes in neutrophils and suggests that autologous neutrophils must circulate in an altered state in the APT patients, thus contributing to the pathology of the disease.

Vulnerability interactive geographic viewer against COVID-19 at the block level in Colombia: Analytical tool based on machine learning techniques.

To mitigate the effects of the coronavirus disease 2019 (COVID-19) pandemic, different countries have developed computational tools and dashboards that generate value for decision-making in public health. We aimed to build an interactive geographic viewer for vulnerability to COVID-19 at the block level in Colombia to identify the location of populations that, because of sociodemographic characteristics and health conditions, could have more complications from COVID-19 infections. The vulnerability levels of the different blocks of 1,102 municipal capitals were calculated. Additionally, the institutions that provide health services and hotels were georeferenced, and changes in people's mobility dynamics in large cities were identified.