scholarly journals Case-Crossover Method with a Short Time-Window

2019 ◽  
Vol 17 (1) ◽  
pp. 202 ◽  
Author(s):  
Mieczysław Szyszkowicz
Keyword(s):  
Time Window ◽  
Conditional Logistic Regression ◽  
Ambient Air ◽  
Epidemiological Studies ◽  
Ambient Air Pollution ◽  
Case Record ◽  
Case Crossover ◽  
Short Time Window ◽  
Short Time ◽  
Pollution Exposure

Numerous epidemiological studies have shown associations between short-term ambient air pollution exposure and various health problems. The time-stratified case-crossover design is a popular technique for estimating these associations. In the standard approach, the case-crossover model is realized by using a conditional logistic regression on data that are interpreted as a set of cases (i.e., individual health events) and controls. In statistical calculations, for each case record, three or four corresponding control records are considered. Here, the case-crossover model is realized as a conditional Poisson regression on counts with stratum indicators. Such an approach enables the reduction of the number of data records that are used in the numerical calculations. In this presentation, the method used analyzes daily counts on the shortest possible time-window, which is composed of two consecutive days. The proposed technique is positively tested on four challenging simulated datasets, for which classical time-series methods fail. The methodology presented here also suggests that the length of exposure (i.e., size of the time-window) may be associated with the severity of health conditions.

scholarly journals Evaluation of the Impact of Black Carbon on the Worsening of Allergic Respiratory Diseases in the Region of Western Serbia: A Time-Stratified Case-Crossover Study

Medicina ◽  
2019 ◽  
Vol 55 (6) ◽  
pp. 261
Author(s):  
Vesna Tomić-Spirić ◽  
Gordana Kovačević ◽  
Jelena Marinković ◽  
Janko Janković ◽  
Anđa Ćirković ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Allergic Asthma ◽  
Black Carbon ◽  
Conditional Logistic Regression ◽  
Positive Association ◽  
Ambient Air ◽  
Epidemiological Studies ◽  
Case Crossover ◽  
Ed Visits ◽  
The Impact

Background and Objectives: Many epidemiological studies have shown a positive association between black carbon (BC) and the exacerbation of allergic rhinitis and allergic asthma. However, none of the studies in Serbia examined this relationship yet. The aim of this study was to examine the associations between BC and emergency department (ED) visits for allergic rhinitis and allergic asthma in the Užice region of Serbia. Materials and Methods: A time-stratified case-crossover design was applied to 523 ED visits for allergic rhinitis and asthma exacerbation that occurred in the Užice region of Serbia between 2012–2014. Data regarding ED visits were routinely collected in the Health Center of Užice. The daily average concentrations of BC were measured by automatic ambient air quality monitoring stations. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were estimated using conditional logistic regression adjusted for the potential confounding influence of weather variables (temperature, humidity, and air pressure). Results: Statistically significant associations were observed between ED visits for allergic rhinitis and 2-day lagged exposure to BC (OR = 3.20; CI = 1.00–10.18; p = 0.049) and allergic asthma and 3-day lagged exposure to BC (OR = 3.23; CI = 1.05–9.95; p = 0.041). Conclusion: Exposure to BC in the Užice region increases the risk of ED visits for allergic rhinitis and asthma, particularly during the heating season.

scholarly journals Is there an association between the level of ambient air pollution and COVID-19?

2020 ◽  
Vol 319 (3) ◽  
pp. L416-L421 ◽  
Author(s):  
Baoming Wang ◽  
Hui Chen ◽  
Yik Lung Chan ◽  
Brian G. Oliver
Keyword(s):  
Air Pollution ◽  
Ambient Air ◽  
Epidemiological Studies ◽  
Ambient Air Pollution ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Air Pollution Exposure ◽  
Human Immune Response ◽  
Human Immune ◽  
Pollution Exposure

Epidemiological studies suggest that environmental factors (e.g., air pollution) can influence the spread and infectivity of coronavirus disease 2019 (COVID-19); however, very few papers have investigated or discussed the mechanism behind the phenomenon. Given the fact that pollution will increase as social distancing rules are relaxed, we summarized the current understanding of how air pollution may affect COVID-19 transmission and discussed several possible mechanisms. Air pollution exposure can dysregulate the human immune response and make people more susceptible to infections, and affect infectivity. For example, in response to exposure to air pollution, angiotensin-converting enzyme 2 will increase, which is the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This may increase the efficiency of viral infection. It is also possible that air pollution can facilitate SARS-CoV-2 spread by increasing the transmission, and potentially, SARS-CoV-2 can also survive longer when attached to a pollutant.

scholarly journals Evaluation of the Impact of Black Carbon on the Worsening of Allergic Respiratory Diseases in the Region of Western Serbia: A Time-Stratified Case-Crossover Study

2019 ◽  
Author(s):  
Vesna Tomić Spirić ◽  
Gordana Kovačević ◽  
Jelena Marinković ◽  
Janko Janković ◽  
Anđa Ćirković ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Allergic Asthma ◽  
Black Carbon ◽  
Conditional Logistic Regression ◽  
Positive Association ◽  
Ambient Air ◽  
Epidemiological Studies ◽  
Case Crossover ◽  
Ed Visits ◽  
The Impact

Background and Objectives: Many epidemiological studies have shown a positive association between black carbon (BC) and the exacerbation of allergic rhinitis and allergic asthma. However, none of the studies in Serbia examined this relationship so far. The aim of this study was to examine the associations between BC and emergency department (ED) visits for allergic rhinitis and allergic asthma in the Užice region of Serbia. Materials and Methods: A time-stratified case-crossover design was applied to 523 ED visits for allergic rhinitis and asthma exacerbation that occurred in the Užice region of Serbia between 2012−2014. Data regarding ED visits were routinely collected in the Health Center of Užice. The daily average concentrations of BC were measured by automatic ambient air quality monitoring stations. Odds ratios and their corresponding 95% confidence intervals were estimated using conditional logistic regression adjusted for the potential confounding influence of weather variables (temperature, humidity, and air pressure). Results: Statistically significant associations were observed between ED visits for allergic rhinitis and 2-day lagged exposure to BC (OR = 3.20; CI = 1.00−10.18; p < 0.05) and allergic asthma and 3-day lagged exposure to BC (OR = 3.23; CI = 1.05−9.95; p < 0.05). Conclusion: Exposure to BC in the Užice region increases the risk of ED visits for allergic rhinitis and asthma, particularly during the heating season.

scholarly journals Differential Effect of Ambient Air Pollution Exposure on Risk of Gestational Hypertension and Preeclampsia

Hypertension ◽  
2019 ◽  
Vol 74 (2) ◽  
pp. 384-390 ◽  
Author(s):  
Carrie J. Nobles ◽  
Andrew Williams ◽  
Marion Ouidir ◽  
Seth Sherman ◽  
Pauline Mendola
Keyword(s):  
Air Pollution ◽  
Differential Effect ◽  
Gestational Hypertension ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Air Pollution Exposure ◽  
Pollution Exposure

scholarly journals 231 A SHORT TIME WINDOW TO PROFIT FROM IL-4 PLUS IL-10 ADDITION TO PROTECT CARTILAGE FROM BLOOD-INDUCED DAMAGE IN VITRO

2011 ◽  
Vol 19 ◽  
pp. S113
Author(s):  
M.E. van Meegeren ◽  
N.W. Jansen ◽  
G. Roosendaal ◽  
S.C. Mastbergen ◽  
F.P. Lafeber
Keyword(s):  
Time Window ◽  
Short Time Window ◽  
Short Time

scholarly journals 383. Feasibility of Specimen Self-collection in Young Children Undergoing SARS-CoV-2 Surveillance for In-person Learning

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S293-S293
Author(s):  
Jonathan Altamirano ◽  
Grace Tam ◽  
Marcela Lopez ◽  
India Robinson ◽  
Leanne Chun ◽  
...  
Keyword(s):  
Young Children ◽  
Time Window ◽  
School Administrators ◽  
Error Rates ◽  
Independent Observer ◽  
Specimen Collection ◽  
Timing Data ◽  
Short Time Window ◽  
Short Time ◽  
Over Time

Abstract Background While pediatric cases of COVID-19 are at low risk for adverse events, schoolchildren should be considered for surveillance as they can become infected at school and serve as sources of household or community transmission. Our team assessed the feasibility of young children self-collecting SARS-CoV-2 samples for surveillance testing in an educational setting. Methods Students at a K-8 school were tested weekly for SARS-CoV-2 from September 2020 - June 2021. Error rates were collected from September 2020 - January 2021. Clinical staff provided all students with instructions for anterior nares specimen self-collection and then observed them to ensure proper technique. Instructions included holding the sterile swab while making sure not to touch the tip, inserting the swab into their nostril until they start to feel resistance, and rubbing the swab in four circles before repeating the process in their other nostril. An independent observer timed random sample self-collections from April - June 2021. Results 2,590 samples were collected from 209 students during the study period when data on error rates were collected. Errors occurred in 3.3% of all student encounters (n=87). Error rates over time are shown in Figure 1, with the highest rate occurring on the first day of testing (n=20/197, 10.2%) and the lowest in January 2021 (n=1/202, 0.5%). 2,574 visits for sample self-collection occurred during the study period when independent timing data was collected (April - June 2021). Of those visits, 7.5% (n=193) were timed. The average duration of each visit was 70 seconds. Figure 1. Swab Error Rates Over Time Conclusion Pediatric self-collected lower nasal swabs are a viable and easily tolerated specimen collection method for SARS-CoV-2 surveillance in school settings, as evidenced by the low error rate and short time window of sample self-collection during testing. School administrators should expect errors to drop quickly after implementing testing. Disclosures All Authors: No reported disclosures

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