short term exposure to ambient air pollution and individual emergency department visits CORD-Papers-2022-06-02 (Version 1)

Title: Short-term exposure to ambient air pollution and individual emergency department visits for COVID-19: a case-crossover study in Canada
Abstract: BACKGROUND: Ambient air pollution is thought to contribute to increased risk of COVID-19 but the evidence is controversial. OBJECTIVE: To evaluate the associations between short-term variations in outdoor concentrations of ambient air pollution and COVID-19 emergency department (ED) visits. METHODS: We conducted a case-crossover study of 78 255 COVID-19 ED visits in Alberta and Ontario Canada between 1 March 2020 and 31 March 2021. Daily air pollution data (ie fine particulate matter with diameter less than 2.5 m (PM(2.5)) nitrogen dioxide (NO(2)) and ozone were assigned to individual case of COVID-19 in 10 km 10 km grid resolution. Conditional logistic regression was used to estimate associations between air pollution and ED visits for COVID-19. RESULTS: Cumulative ambient exposure over 03 days to PM2.5 (OR 1.010; 95% CI 1.004 to 1.015 per 6.2 g/m(3)) and NO(2) (OR 1.021; 95% CI 1.015 to 1.028 per 7.7 ppb) concentrations were associated with ED visits for COVID-19. We found that the association between PM(2.5) and COVID-19 ED visits was stronger among those hospitalised following an ED visit as a measure of disease severity (OR 1.023; 95% CI 1.015 to 1.031) compared with those not hospitalised (OR 0.992; 95% CI 0.980 to 1.004) (p value for effect modification=0.04). CONCLUSIONS: We found associations between short-term exposure to ambient air pollutants and COVID-19 ED visits. Exposure to air pollution may also lead to more severe COVID-19 disease.
Published: 2022-03-30
Journal: Thorax
DOI: 10.1136/thoraxjnl-2021-217602
DOI_URL: http://doi.org/10.1136/thoraxjnl-2021-217602
Author Name: Lavigne Eric
Author link: https://covid19-data.nist.gov/pid/rest/local/author/lavigne_eric
Author Name: Ryti Niilo
Author link: https://covid19-data.nist.gov/pid/rest/local/author/ryti_niilo
Author Name: Gasparrini Antonio
Author link: https://covid19-data.nist.gov/pid/rest/local/author/gasparrini_antonio
Author Name: Sera Francesco
Author link: https://covid19-data.nist.gov/pid/rest/local/author/sera_francesco
Author Name: Weichenthal Scott
Author link: https://covid19-data.nist.gov/pid/rest/local/author/weichenthal_scott
Author Name: Chen Hong
Author link: https://covid19-data.nist.gov/pid/rest/local/author/chen_hong
Author Name: To Teresa
Author link: https://covid19-data.nist.gov/pid/rest/local/author/to_teresa
Author Name: Evans Greg J
Author link: https://covid19-data.nist.gov/pid/rest/local/author/evans_greg_j
Author Name: Sun Liu
Author link: https://covid19-data.nist.gov/pid/rest/local/author/sun_liu
Author Name: Dheri Aman
Author link: https://covid19-data.nist.gov/pid/rest/local/author/dheri_aman
Author Name: Lemogo Lionnel
Author link: https://covid19-data.nist.gov/pid/rest/local/author/lemogo_lionnel
Author Name: Kotchi Serge Olivier
Author link: https://covid19-data.nist.gov/pid/rest/local/author/kotchi_serge_olivier
Author Name: Stieb Dave
Author link: https://covid19-data.nist.gov/pid/rest/local/author/stieb_dave
sha: 1735b63453203a919259873a78c7381632c52897
license: cc-by
license_url: https://creativecommons.org/licenses/by/4.0/
source_x: Medline; PMC; WHO
source_x_url: https://www.medline.com/https://www.ncbi.nlm.nih.gov/pubmed/https://www.who.int/
pubmed_id: 35361687
pubmed_id_url: https://www.ncbi.nlm.nih.gov/pubmed/35361687
pmcid: PMC8983401
pmcid_url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8983401
url: https://doi.org/10.1136/thoraxjnl-2021-217602 https://www.ncbi.nlm.nih.gov/pubmed/35361687/
has_full_text: TRUE
Keywords Extracted from Text Content: lagresponse R t patient COVID-19 mixmeta two-metre OxCGRT O 3 COVID-19 Tracker I 2 PM 2.5 41 42 extract COVID-19-cases EDs airway CCHS modification=0.01 Canadians between-health μg/m 3 O 3 CIs Ontario pulmonary DAG nitrogen dioxide COVID-19 patients ≥65 SES O 3 . modifica-tion=0.04 O 3 * myocardial PM 2.5 10.75°C PM 10 pollution-COVID-19 × Cochran's Q-test DLNMs patients U07.1 'COVID-19 U07.2 'COVID-19 r=−0.11 S4-S6 gaseous pollutants lag-response −33.34°C NO 2 28.51°C 7-14 https://creativecommons.org/ licenses/by/4.0/. Eric
Extracted Text Content in Record: First 5000 Characters:Over the past decades, a large number of studies have shown that acute and chronic exposure to ambient air pollution is associated with increased morbidity and mortality. 1 Globally, ambient air pollution is the leading environmental risk factor for deaths and disability based on estimates of the Global Burden of Disease initiative. 2 Previous studies have shown associations between daily levels of ambient air pollution and acute pulmonary events, including respiratory tract infections. 3 4 4-8 In particular, recent evidence suggests that shortterm exposure to air pollution may increase the risk of worse outcomes in patients with COVID- 19. 9 Recent reports based on epidemiological timeseries studies have found positive associations of short-term exposure to ambient air pollution and daily new confirmed cases of COVID-19. 10 11 In fact, exposure to air pollution may impair airway immunity which may increase susceptibility to respiratory pathogens. Air pollution may also alter immune response to the infection and therefore lead to more severe disease. 5 While recent reports indicate a possible link between short-term variations in outdoor concentrations of ambient air pollution and COVID-19, none of these studies have used individual-level data. Individual-level assessment would also allow more robust investigation of effect modification by individual characteristics (eg, age, sex), including those related to characteristics of COVID-19 diagnosis. The general objective of this study was to test the hypothesis that short-term variations in outdoor concentrations of ambient air pollution increase the risk of emergency department (ED) visits for COVID-19. We also hypothesised that short-term variations in outdoor concentrations of ambient air pollution are associated with presence of pneumonia at the time of COVID-19 diagnosis in the A time-stratified case-crossover study was conducted across 40 health regions in Canada in order to estimate associations between short-term variations in outdoor concentrations of ambient air pollution and risk of ED visits for COVID-19. The case-crossover design is an adaptation of the case-control study in which cases serve as their own control, and it is well suited for studying transient risk factors 14 (online supplemental file 1 for additional details). The case's exposure at the index time (ie, day of admission for COVID-19) is compared with its exposure at control time intervals, which are chosen using a timestratified design. 15 The index period is measured before the event and the control period is measured before and after the event. [16] [17] [18] Referent intervals were selected from the same day of the week during the same month as the case interval (ie, 1:3 or 1:4 matching). For example, if the COVID-19 ED visit occurred on the second Wednesday in the month of January 2021, then the referent periods will be the other Wednesdays in January 2021, regardless if these occurred before or after the event. In fact, the time-stratified approach matches the exposure by day of the week and month to control for the influence of day-of-week effects. In addition, the time stratified approach is not subject to bias resulting from time trends and inherently takes into account seasonal trends in either the exposure levels and outcome data as well as for unmeasured subject-level risk factors (eg, obesity) that do no vary over short periods of time. 15 19 20 Health outcomes and data All ED cases of COVID-19 occuring between 1 March 2020 and 31 March 2021 in 40 health regions across the provinces of Ontario (35 health regions) and Alberta (5 health regions) in Canada were identified from the National Ambulatory Care Reporting System (NACRS) database maintained by CIHI. 21 Data were not available for other provinces for the time period under study given that only hospitals in Ontario and Alberta had mandated reporting for ED visits with diagnosis codes and were available when this study was initiated. Canada provides universal healthcare coverage for its residents; therefore, the NACRS database contain the large majority of ED visits in the provinces of Ontario and Alberta. Although the first patient being diagnosed with COVID-19 in Canada was identified on 25 January 2020, we limited our time period when the first wave of COVID-19 began around March 2020. Therefore, our study period overlapped the first wave as well as the second wave of COVID-19 cases, which occurred between October 2020 and February 2021. The following codes were identified from the main diagnosis to identify ED visits for COVID-19: International Classification of Diseases (ICD)-10th revision, Code U07.1 'COVID-19 case with virus identified by laboratory results', and U07.2 'COVID-19 case diagnosed clinically or epidemiologically but laboratory results are inconclusive, not available or testing is not performed'. After identifying the COVID-19-cases, we searched secondary diagnostic fields for viral pneumonia (ICD-1
Keywords Extracted from PMC Text: factors14 confounders.38 EDs modification.33 patients CIs COVID-19 patients minorities.47–50 r=−0.11 ≥65 DLNMs two-metre pandemic.53 μg/m3 cases.34 time-stratified lag-response COVID-19.10 11 PM2.541 42 Code U07.1 'COVID-19 pollution.18 53 COVID-19.12 13 A pollution)24 gaseous pollutants43 44 chemokines.44 O3 COVID-19 modification=0.01 pulmonary COVID-19-cases COVID-19 CIHI.21 10.75°C 's OxCGRT CCHS Canadians SES between-health COVID-19 cases.10 A third facility).37 pollution–COVID-19 myocardial U07.2 'COVID-19 extract NO2 −33.34°C × Tracker variable.31 Ontario DAG estimates.33 mortality.1 airway pollution-COVID-19 visits).25 mixmeta 28.51°C O3 patient PM10
Extracted PMC Text Content in Record: First 5000 Characters:Over the past decades, a large number of studies have shown that acute and chronic exposure to ambient air pollution is associated with increased morbidity and mortality.1 Globally, ambient air pollution is the leading environmental risk factor for deaths and disability based on estimates of the Global Burden of Disease initiative.2 Previous studies have shown associations between daily levels of ambient air pollution and acute pulmonary events, including respiratory tract infections.3 4 4–8 In particular, recent evidence suggests that short-term exposure to air pollution may increase the risk of worse outcomes in patients with COVID-19.9 Recent reports based on epidemiological time-series studies have found positive associations of short-term exposure to ambient air pollution and daily new confirmed cases of COVID-19.10 11 In fact, exposure to air pollution may impair airway immunity which may increase susceptibility to respiratory pathogens. Air pollution may also alter immune response to the infection and therefore lead to more severe disease.5 While recent reports indicate a possible link between short-term variations in outdoor concentrations of ambient air pollution and COVID-19, none of these studies have used individual-level data. Individual-level assessment would also allow more robust investigation of effect modification by individual characteristics (eg, age, sex), including those related to characteristics of COVID-19 diagnosis. The general objective of this study was to test the hypothesis that short-term variations in outdoor concentrations of ambient air pollution increase the risk of emergency department (ED) visits for COVID-19. We also hypothesised that short-term variations in outdoor concentrations of ambient air pollution are associated with presence of pneumonia at the time of COVID-19 diagnosis in the ED. This is particularly important, because it may indicate a more severe manifestation of COVID-19.12 13 A time-stratified case-crossover study was conducted across 40 health regions in Canada in order to estimate associations between short-term variations in outdoor concentrations of ambient air pollution and risk of ED visits for COVID-19. The case-crossover design is an adaptation of the case-control study in which cases serve as their own control, and it is well suited for studying transient risk factors14 (online supplemental file 1 for additional details). The case's exposure at the index time (ie, day of admission for COVID-19) is compared with its exposure at control time intervals, which are chosen using a time-stratified design.15 The index period is measured before the event and the control period is measured before and after the event.16–18 Referent intervals were selected from the same day of the week during the same month as the case interval (ie, 1:3 or 1:4 matching). For example, if the COVID-19 ED visit occurred on the second Wednesday in the month of January 2021, then the referent periods will be the other Wednesdays in January 2021, regardless if these occurred before or after the event. In fact, the time-stratified approach matches the exposure by day of the week and month to control for the influence of day-of-week effects. In addition, the time stratified approach is not subject to bias resulting from time trends and inherently takes into account seasonal trends in either the exposure levels and outcome data as well as for unmeasured subject-level risk factors (eg, obesity) that do no vary over short periods of time.15 19 20 All ED cases of COVID-19 occuring between 1 March 2020 and 31 March 2021 in 40 health regions across the provinces of Ontario (35 health regions) and Alberta (5 health regions) in Canada were identified from the National Ambulatory Care Reporting System (NACRS) database maintained by CIHI.21 Data were not available for other provinces for the time period under study given that only hospitals in Ontario and Alberta had mandated reporting for ED visits with diagnosis codes and were available when this study was initiated. Canada provides universal healthcare coverage for its residents; therefore, the NACRS database contain the large majority of ED visits in the provinces of Ontario and Alberta. Although the first patient being diagnosed with COVID-19 in Canada was identified on 25 January 2020, we limited our time period when the first wave of COVID-19 began around March 2020. Therefore, our study period overlapped the first wave as well as the second wave of COVID-19 cases, which occurred between October 2020 and February 2021. The following codes were identified from the main diagnosis to identify ED visits for COVID-19: International Classification of Diseases (ICD)-10th revision, Code U07.1 'COVID-19 case with virus identified by laboratory results', and U07.2 'COVID-19 case diagnosed clinically or epidemiologically but laboratory results are inconclusive, not available or testing is not performed'. After identifying the COVID-19-cases, we
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