Nicolás Valdés Ortega
A5024909749- Climate Change and Health Impacts
- Air Quality and Health Impacts
- Global Health Care Issues
- Health disparities and outcomes
- Thermoregulation and physiological responses
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Respiratory Support and Mechanisms
- Nutrition and Health in Aging
- Prostate Cancer Treatment and Research
- COVID-19 epidemiological studies
- COVID-19 Clinical Research Studies
- Neonatal Respiratory Health Research
- COVID-19 impact on air quality
- Energy and Environment Impacts
- Urologic and reproductive health conditions
- Prostate Cancer Diagnosis and Treatment
- Long-Term Effects of COVID-19
- Renaissance and Early Modern Studies
- Pancreatitis Pathology and Treatment
- Emergency and Acute Care Studies
- Stress and Burnout Research
- Medical research and treatments
- Healthcare Systems and Public Health
- COVID-19 Pandemic Impacts
- Occupational Health and Safety in Workplaces
Universidad de Los Andes, Chile
2017-2024
Pontificia Universidad Católica de Chile
2024
Vall d'Hebron Hospital Universitari
2022
Universitat Autònoma de Barcelona
2022
Research Network (United States)
2021
Oeschger Centre for Climate Change Research
2021
University of Bern
2021
Universidad de Los Andes
2019
Health Canada
2019
Universidad de Málaga
2017
The systematic evaluation of the results time-series studies air pollution is challenged by differences in model specification and publication bias.We evaluated associations inhalable particulate matter (PM) with an aerodynamic diameter 10 μm or less (PM10) fine PM 2.5 (PM2.5) daily all-cause, cardiovascular, respiratory mortality across multiple countries regions. Daily data on were collected from 652 cities 24 We used overdispersed generalized additive models random-effects meta-analysis...
Climate change can directly affect human health by varying exposure to non-optimal outdoor temperature. However, evidence on this direct impact at a global scale is limited, mainly due issues in modelling and projecting complex highly heterogeneous epidemiological relationships across different populations climates.We collected observed daily time series of mean temperature mortality counts for all causes or non-external only, periods ranging from Jan 1, 1984, Dec 31, 2015, various locations...
BackgroundExposure to cold or hot temperatures is associated with premature deaths. We aimed evaluate the global, regional, and national mortality burden non-optimal ambient temperatures.MethodsIn this modelling study, we collected time-series data on from 750 locations in 43 countries five meta-predictors at a grid size of 0·5° × across globe. A three-stage analysis strategy was used. First, temperature–mortality association fitted for each location by use regression. Second, multivariate...
Background Heatwaves are a critical public health problem. There will be an increase in the frequency and severity of heatwaves under changing climate. However, evidence about impacts climate change on heatwave-related mortality at global scale is limited. Methods findings We collected historical daily time series mean temperature for all causes or nonexternal causes, periods ranging from January 1, 1984, to December 31, 2015, 412 communities within 20 countries/regions. estimated...
The health burden associated with temperature is expected to increase due a warming climate. Populations living in cities are likely be particularly at risk, but the role of urban characteristics modifying direct effects on still unclear. In this contribution, we used multi-country dataset study effect modification temperature-mortality relationships by range city-specific indicators.We collected ambient and mortality daily time-series data for 340 22 countries, periods between 1985 2014....
Abstract Objective To evaluate the short term associations between nitrogen dioxide (NO 2 ) and total, cardiovascular, respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol. Design Two stage, time series approach, with overdispersed generalised linear models multilevel meta-analysis. Setting 398 cities in 22 low to high income countries/regions. Main outcome measures Daily deaths from total (62.8 million), cardiovascular (19.7 (5.5 million)...
Background: There is strong experimental evidence that physiologic stress from high temperatures greater if humidity higher. However, heat indices developed to allow for this have not consistently predicted mortality better than dry-bulb temperature. Objectives: We aimed clarify the potential contribution of an addition temperature in predicting daily summer by using a large multicountry dataset. Methods: In 445 cities 24 countries, we fit time-series regression model with distributed lag...
To investigate potential interactive effects of fine particulate matter (PM
Older adults are generally amongst the most vulnerable to heat and cold. While temperature-related health impacts projected increase with global warming, influence of population aging on these trends remains unclear. Here we show that at 1.5 °C, 2 3 °C heat-related mortality in 800 locations across 50 countries/areas will by 0.5%, 1.0%, 2.5%, respectively; among which 1 5 4 deaths can be attributed aging. Despite a decrease cold-related due progressive warming alone, mostly counteract this...
The Paris Agreement binds all nations to undertake ambitious efforts combat climate change, with the commitment "hold warming well below 2 °C in global mean temperature (GMT), relative pre-industrial levels, and pursue limit 1.5 °C". constitutes an goal for which greater evidence on its benefits health would help guide policy potentially increase motivation action. Here we contribute this gap assessment potential benefits, terms of reductions temperature-related mortality, derived from...
Introduction: This study aimed to look into possible correlations between male age and different sperm parameters derived from semen analysis deoxyribonucleic acid (DNA) fragmentation.Methods: retrospective descriptive included 2681 patients who underwent at Clínica Las Condes (CLC), Santiago, Chile, January 2014 May 2017; were analyzed.Results: Males above the of 50 significantly more likely present anomalies in volume, concentration, DNA fragmentation; males aged 41+ years have lower...
Background: The association between fine particulate matter (PM 2.5 ) and mortality widely differs as well within countries. Differences in PM composition can play a role modifying the effect estimates, but there is little evidence about which components have higher impacts on mortality. Methods: We applied 2-stage analysis data collected from 210 locations 16 In first stage, we estimated location-specific relative risks (RR) for associated with daily total through time series regression...
Epidemiological evidence on short-term association between ambient carbon monoxide (CO) and mortality is inconclusive limited to single cities, regions, or countries. Generalisation of results from previous studies hindered by potential publication bias different modelling approaches. We therefore assessed the exposure CO daily in a multicity, multicountry setting.We collected data air pollution, meteorology, total 337 cities 18 countries covering various periods 1979 2016. All included had...
Minimum mortality temperature (MMT) is an important indicator to assess the temperature-mortality association, indicating long-term adaptation local climate. Limited evidence about geographical variability of MMT available at a global scale.We collected data from 658 communities in 43 countries under different climates. We estimated associations derive for each community using Poisson regression with distributed lag nonlinear models. investigated variation by climatic zone mixed-effects...
BackgroundIncreased mortality risk is associated with short-term temperature variability. However, to our knowledge, there has been no comprehensive assessment of the variability-related burden worldwide. In this study, using data from MCC Collaborative Research Network, we first explored association between variability and across 43 countries or regions. Then, provide a more picture global variability, gridded resolution 0·5° × were used assess at global, regional, national levels....
BackgroundClimate change can directly impact temperature-related excess deaths and might subsequently the seasonal variation in mortality. In this study, we aimed to provide a systematic comprehensive assessment of potential future changes variation, or seasonality, mortality across different climate zones.MethodsIn modelling collected daily time series mean temperature (all causes non-external only) via Multi-Country Multi-City Collaborative (MCC) Research Network. These data were during...
BackgroundExposure to cold spells is associated with mortality. However, little known about the global mortality burden of spells.MethodsA three-stage meta-analytical method was used estimate by means a time series dataset 1960 locations across 59 countries (or regions). First, we fitted location-specific, spell-related associations using quasi-Poisson regression distributed lag non-linear model period up 21 days. Second, built multivariate meta-regression between location-specific and seven...
Assessing the association between temperature frequency and mortality can provide insights into human adaptation to local ambient temperatures. We collected daily time-series data on from 757 locations in 43 countries during 1979–2020. used a two-stage time series design assess all-cause mortality. The results were pooled at national, regional, global levels. observed consistent decrease risk of as normalized increases across globe. average increase comparing 10th 100th percentile was 13.03%...
Abstract The rising humid heat is regarded as a severe threat to human survivability, but the proper integration of into heat-health alerts still being explored. Using state-of-the-art epidemiological and climatological datasets, we examined association between multiple stress indicators (HSIs) daily mortality in 739 cities worldwide. Notable differences were observed long-term trends timing events detected by HSIs. Air temperature (Tair) predicts heat-related well with robust negative...