Time-stratified Case-crossover Study Research Articles

Association between ambient temperature and genitourinary emergency ambulance dispatches in Japan: A nationwide case-crossover study.

Although the effects of temperature on genitourinary morbidity and mortality have been investigated in several countries, it remains largely unexplored in Japan. We investigated the association between ambient temperature and genitourinary emergency ambulance dispatches (EADs) in Japan and the modifying roles of sex, age, and illness severity. We conducted a time-stratified case-crossover study with conditional quasi-Poisson regression to estimate the association between mean temperature and genitourinary EADs in all prefectures of Japan between 2015 and 2019. A mixed-effects meta-analysis was used to pool the association at the country level. Subgroup analyses were performed to explore differences in associations stratified by sex, age, and illness severity. We found an increased risk of genitourinary EAD associated with higher temperatures. The cumulative relative risk (RR) at the 99th temperature percentile compared with that at the 1st percentile was 1.74 (95% confidence interval (CI) = [1.60, 1.89]). We observed higher heat-related RRs in males (RR = 1.89; 95% CI = [1.73, 2.07]) than females (RR = 1.56; 95% CI = [1.37, 1.76]), and in the younger (RR = 2.13; 95% CI = [1.86, 2.45]) than elderly (RR = 1.39; 95% CI = [1.22, 1.58]). We found a significant association for those with mild or moderate cases (RR = 1.77; 95% CI = [1.62, 1.93]), but not for severe or life-threatening cases (RR = 1.20; 95% CI = [0.80, 1.82]). Our study revealed heat effects on genitourinary EADs in Japan. Men, youth, and mild-moderate illnesses were particularly vulnerable subgroups. These findings underscore the need for preventative measures aimed at mitigating the impact of temperature on genitourinary emergencies.

Dust particulate matter increases pulmonary embolism onset: A nationwide time-stratified case-crossover study in China

BackgroundParticulate matter (PM) has been found to elevate the risk of pulmonary embolism (PE) onset. Among the contributors to PM, dust PM stands as the second natural source, and its emissions are escalating due to climate change. Despite this, information on the effect of dust PM on PE onset is scarce. Hence, this study aims to investigate the impacts of dust PM10, dust PM2.5–10, and dust PM2.5 on PE onset. MethodsA nationwide time-stratified case-crossover study was conducted between 2015 and 2020, using data from 18,616 PE onset cases across 1,921 hospitals in China. The analysis employed a conditional logistic regression model to quantify the associations between dust PM10, dust PM2.5–10, and dust PM2.5 and PE onset. Furthermore, the study explored the time-distributed lag pattern of the effect of dust PM on PE development. Stratified analyses were performed based on sex, age, region, and season. ResultsDust PM10, dust PM2.5–10, and dust PM2.5 exhibited significant health effects on PE onset, particularly concerning exposure on the same day. The peak estimates were observed at lag 01 day, with the odds ratio being 1.011 [95 % confidence interval (CI): 1.003, 1.019], 1.014 (95 % CI: 1.003, 1.026), and 1.039 (95 % CI: 1.011, 1.068), for a 10 μg/m3 increase in the concentration of dust PM10, dust PM2.5–10, and dust PM2.5, respectively. In addition, the study identified a higher risk of PE onset associated with dust PM exposure during the warm season than that in cool season, particularly for dust PM2.5. ConclusionsThe findings from this study suggest that short-term exposure to dust PM, particularly dust PM2.5, may trigger PE onset, posing a significant health threat. Implementing measures to mitigate dust PM emissions and protect patients with PE from dust PM exposure is imperative.

Hourly Heat Exposure and Acute Ischemic Stroke

Previous studies have demonstrated the associations of daily high temperature with hospitalizations and mortality from ischemic stroke, but the hourly association of ambient heat and acute ischemic stroke (AIS) onset has been rarely examined. To evaluate the association between hourly high ambient temperature and the onset of AIS. This time-stratified case-crossover study was conducted using a nationwide registry that collects data from more than 200 stroke centers in China. Participants were adult patients with AIS who were hospitalized in the warm seasons between January 1, 2019, and December 31, 2021. Hourly temperature and single-hour temperature exposure lag up to 24 hours before the AIS onset (lag 0 hours to lag 24 hours). The main outcome was onset of AIS. Associations between hourly mean temperatures and AIS onset were analyzed using conditional logistic regression integrated with the distributed lag nonlinear model. Stratification analyses were applied to examine potential association modifiers. Several sensitivity analyses were conducted to examine the robustness of the results. A total of 82 455 patients with AIS (mean [SD] age, 65.8 [11.9] years; 52 267 males [63.4%]) were included in the final analysis. A monotonically increasing risk of AIS onset was associated with higher temperatures. The excess AIS risk occurred immediately at lag 0 hours and persisted for 10 hours. Compared with the reference temperature (12.1 °C), the cumulative odds ratio (OR) over lag 0 to 10 hours of AIS onset associated with extremely high temperature (33.3 °C) was 1.88 (95% CI, 1.65-2.13) nationwide. The exposure-response curve was steeper in the north than in the south (OR, 1.80 [95% CI, 1.53-2.11] vs 1.57 [95% CI, 1.31-1.87]). The ORs were greater for males and patients with a history of dyslipidemia or atrial fibrillation, but the differences were not significant. Results of this study suggest that hourly heat exposure is associated with increased risk of AIS onset. This finding may benefit the formulation of public health strategies to reduce cerebrovascular risk associated with high ambient temperature under global warming.

Disparities in the association between ambient temperature and preterm birth according to individual and regional characteristics: a nationwide time-stratified case-crossover study

BackgroundSeveral studies have reported that climate change elevates heat exposure in pregnant women and high temperatures during pregnancy are associated with preterm births (PTBs). Although the association might be disproportionate, related evidence remains sparse. We evaluated the disproportionate risk of PTB associated with ambient temperature during pregnancy by individual and regional characteristics in South Korea.MethodsWe collected data on birth certificates and daily mean temperatures during the period from 2011 to 2019. A time-stratified case-crossover design was used to investigate the association between temperature and PTB and stratified analyses were conducted to examine the effect modification of individual and regional characteristics.ResultsA total of 160,067 singleton PTBs were recorded in Korea from 2011 to 2019. A 5℃ increase in the mean temperature during the last four weeks before delivery was associated with an increased risk of PTB with an odds ratio (OR) of 1.03 (95% confidence interval [CI]: 1.02, 1.05), and the association was more evident in mothers aged ≥35 years (OR: 1.06 [95% CI: 1.03, 1.10]) and with low education levels (OR: 1.04 [95% CI: 1.02, 1.05]). Additionally, the estimated risk was evident in districts with lower medical resources and more prominent disparities were shown by individual and regional characteristics in rural areas than in urban areas.ConclusionsThis study provides evidence that the risk of PTB related to ambient temperature is disproportionate by individual and regional characteristics and suggests the need for public health policies to alleviate the disparities, especially in rural areas.

Associations between short-term exposure to ambient temperature and renal disease mortality in Japan during 1979-2019: A time-stratified case-crossover analysis.

Previous studies have indicated that renal disease mortality is sensitive to ambient temperatures. However, most have been limited to the summer season with inconclusive evidence for changes in population vulnerability over time. This study aims to examine the association between short-term exposure to ambient temperatures and mortality due to renal diseases in Japan, and how this association varied over time. We conducted a two-stage, time-stratified case-crossover study from 1979 to 2019 across 47 prefectures of Japan. We obtained the data of daily mortality counts for all renal diseases, acute renal failure, and chronic renal disease. We fitted a conditional quasi-Poisson regression model with a distributed lag nonlinear model. A random-effects meta-analysis was applied to calculate national averages. We performed additional analyses by four subperiods, sex, and age groups. We analyzed 997,590 renal mortality cases and observed a reversed J-shaped association. Lower temperatures were associated with increased mortality in all renal disease categories. The cumulative relative risks at 2.5th percentile compared to the minimum mortality temperature percentile were 1.34 (95% confidence interval [CI] = 1.29, 1.40), 1.51 (95% CI = 1.33, 1.71), and 1.33 (95% CI = 1.24, 1.43) for all renal, acute renal failure, and chronic renal disease mortality, respectively. The associations were observed in individuals of both sexes and aged 65 years and above. The associations of kidney mortality with low temperature remained consistent, while the associations with high temperature were pronounced in the past, but not in recent periods. Protection for individuals with impaired renal function from exposure to low temperatures during cold seasons is warranted.

P1105 Short-term exposure to environmental air pollution and inflammatory bowel disease flares: a time-stratified case cross-over study

Abstract Background Some epidemiological studies suggest that long-term exposure to environmental air pollutants, such as particulate matter (PM), could have a role in inflammatory bowel disease (IBD) incidence and pathogenesis. However, less is known about the potential effect of short-term air pollution exposure. The aim of this study is to investigate whether short-term exposure to environmental air pollution is associated with the occurrence of IBD flares. Methods Anonymized hospital discharge records (HDR) with ICD-9-CM codes 555 (Crohn’s disease) and 556 (ulcerative colitis) for years 2002-2009 from all hospitals of the Lombardy region were collected. All HDR of adult patients (18-75 years) resident in Milan were included, except for recurrent hospitalizations within 6 months. Each record was assigned daily PM ≤10 µm (PM10) concentrations at municipality level by averaging PM10 levels of the day of admission with the levels of the day before (lag01) and of each preceding day up to six days before (lag06). To evaluate the association between PM10 and IBD-related hospitalizations, a time-stratified case-crossover study design was applied. Conditional logistic regression models, calculating Odds Ratios (OR) and 95% Confidence Intervals (95%CI) per increments of 10 µg/m3 of PM10, were performed. Results Overall, 2,176 hospital admissions (males=1,137, Crohn’s disease=1,264, ulcerative colitis=912) were included. In the entire population no clear association between PM10 and IBD-related hospitalization was identified, notwithstanding a small risk increase for males (OR: 1.03; 95%CI: 0.99-1.08 at lag04). When further stratifying for ICD code, an increased risk of hospitalization for "left-sided ulcerative colitis" (ICD code: 556.5) was found in males only, for exposures in all days preceding hospitalization up to lag04 (1.28; 1.05-1.28; 59 cases, 207 controls) (Figure 1). In females, the association was weaker, although positive (1.14; 0.91-1.42; 49 cases, 164 controls). No relevant findings emerged when looking at other ICD codes. Conclusion We observed an increased risk of IBD-related hospitalization in male patients with left-sided ulcerative colitis per increasing levels of air pollution in the days preceding hospital admission. Although preliminary, our findings suggest the possible role of sex as an effect modifier of the influence that air pollution might exert on IBD flares. Further studies are needed to better comprehend the complex framework characterizing the interplay between environmental and individual factors contributing to IBD.

Short-term high temperature may increase the incidence risk of collective conflicts: A case-crossover study in the Greater Middle East

BackgroundViolent conflict is a formidable global challenge, with long-lasting impacts on individual health and society security. There has been compelling evidence that heat can increase aggression intention on the individual level. However, little is known about the short-term relationship between ambient temperature and collective violent conflicts, especially in less developed regions. MethodWe conducted a time-stratified case-crossover study combined with the distributed lag nonlinear model (DLNM) among 247,773 violent conflicts from 29 countries or regions in the Greater Middle East, between 1997 and 2021. Potential modification effects of economic status and climate conditions were explored by stratified analyses. Negative control and sensitivity analyses were also performed to test the robustness of our model. ResultsWe observed significant associations between higher temperature and the onset of five categories of violent conflicts. The effects generally occurred within the first several days after exposure. The incidence risks of battles, violence against civilians, explosions/remote violence, protests and riots were 1.60 [95 % confidence interval (CI): 1.31–1.95], 1.82 (95 % CI: 1.37–2.42), 1.24 (95 % CI: 1.08–1.41), 1.16 (95 % CI: 1.09–1.24) and 1.54 (95 % CI: 1.22–1.95) when comparing extreme high temperatures to minimum-risk temperatures. The associations were generally more prominent in areas with lower economic levels and associations in regions of the continental climate are also stronger. ConclusionsOur finding reveals novel and concrete evidence that short-term high temperature could increase the risk of multiple forms of violent conflict in the Greater Middle East and provides new insights into the potential short-term mechanisms under the heat-collective violence association.

Short-Term Increases in NO2 and O3 Concentrations during Pregnancy and Stillbirth Risk in the U.S.: A Time-Stratified Case-Crossover Study.

Associations between gaseous pollutant exposure and stillbirth have focused on exposures averaged over trimesters or gestation. We investigated the association between short-term increases in nitrogen dioxide (NO2) and ozone (O3) concentrations and stillbirth risk among a national sample of 116 788 Medicaid enrollees from 2000 to 2014. A time-stratified case-crossover design was used to estimate distributed (lag 0-lag 6) and cumulative lag effects, which were adjusted for PM2.5 concentration and temperature. Effect modification by race/ethnicity and proximity to hydraulic fracturing (fracking) wells was assessed. Short-term increases in the NO2 and O3 concentrations were not associated with stillbirth in the overall sample. Among American Indian individuals (n = 1694), a 10 ppb increase in NO2 concentrations was associated with increased stillbirth odds at lag 0 (5.66%, 95%CI: [0.57%, 11.01%], p = 0.03) and lag 1 (4.08%, 95%CI: [0.22%, 8.09%], p = 0.04) but not lag 0-6 (7.12%, 95%CI: [-9.83%, 27.27%], p = 0.43). Among participants living in zip codes within 15 km of active fracking wells (n = 9486), a 10 ppb increase in NO2 concentration was associated with increased stillbirth odds in single-day lags (2.42%, 95%CI: [0.37%, 4.52%], p = 0.02 for lag 0 and 1.83%, 95%CI: [0.25%, 3.43%], p = 0.03 for lag 1) but not the cumulative lag (lag 0-6) (4.62%, 95%CI: [-2.75%, 12.55%], p = 0.22). Odds ratios were close to the null in zip codes distant from fracking wells. Future studies should investigate the role of air pollutants emitted from fracking and potential racial disparities in the relationship between short-term increases in NO2 concentrations and stillbirth.

Ambient PM2.5 and cardiopulmonary mortality in the oldest-old people in China: A national time-stratified case-crossover study

Evidence on the associations of fine particulate matter (PM2.5) with cardiopulmonary mortality in the oldest-old (aged 80+ years) people remains limited. We conducted a time-stratified case-crossover study of 1,475,459 deaths from cardiopulmonary diseases in China to estimate the associations between short-term exposure to ambient PM2.5 and cardiopulmonary mortality among the oldest-old people. Each 10μg/m3 increase in PM2.5 concentration (6-day moving average [lag05]) was associated with higher mortality from cardiopulmonary diseases (excess risks [ERs]= 1.69%, 95% confidence interval [CI]: 1.54%, 1.84%), cardiovascular diseases (ER= 1.72%, 95% CI: 1.54%, 1.90%), and respiratory diseases (ER= 1.62%, 95% CI: 1.33%, 1.91%). Compared to the other groups, females (ER= 1.94%, 95% CI: 1.73%, 2.15%) (p for difference test= 0.043) and those aged 95-99 years (ER= 2.31%, 95% CI: 1.61%, 3.02%) (aged 80-85 years old was the reference, p for difference test= 0.770) presented greater mortality risks. We found 14 specific cardiopulmonary causes associated with PM2.5, out of which emphysema (ER= 3.20%, 95% CI: 1.57%, 4.86%) had the largest association. Out of the total deaths, 6.27% (attributable fraction [AF], 95% CI: 5.72%, 6.82%) were ascribed to short-term PM2.5 exposure. This study provides evidence of PM2.5-induced cardiopulmonary mortality and calls for targeted prevention actions for the oldest-old people. This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Foreign Expert Program of the Ministry of Science and Technology, the Natural Science Foundation of Guangdong, China, and the Science and Technology Program of Guangzhou.

The impact of ambient temperature and air pollution on SARS-CoV2 infection and Post COVID-19 condition in Belgium (2021–2022)

IntroductionThe associations between non-optimal ambient temperature, air pollution and SARS-CoV-2 infection and post COVID-19 condition (PCC) remain constrained in current understanding. We conducted a retrospective analysis to explore how ambient temperature affected SARS-CoV-2 infection in individuals who later developed PCC compared to those who did not. We investigated if these associations were modified by air pollution. MethodsWe conducted a bidirectional time-stratified case-crossover study among individuals who tested positive for SARS-CoV-2 between May 2021 and June 2022. We included 6302 infections, with 2850 PCC cases. We used conditional logistic regression and distributed lag non-linear models to obtain odds ratios (OR) and 95% confidence intervals (CI) for non-optimal temperatures relative to the period median temperature (10.6 °C) on lags 0 to 5. For effect modification, daily average PM2.5 concentrations were categorized using the period median concentration (8.8 μg/m3). Z-tests were used to compare the results by PCC status and PM2.5. ResultsNon-optimal cold temperatures increased the cumulative odds of infection (OR = 1.93; 95%CI:1.67–2.23, OR = 3.53; 95%CI:2.72–4.58, for moderate and extreme cold, respectively), with the strongest associations observed for non-PCC cases. Non-optimal heat temperatures decreased the odds of infection except for moderate heat among PCC cases (OR = 1.32; 95%CI:0.89–1.96). When PM2.5 was >8.8 μg/m3, the associations with cold were stronger, and moderate heat doubled the odds of infection with later development of PCC (OR = 2.18; 95%CI:1.01–4.69). When PM2.5 was ≤8.8 μg/m3, exposure to non-optimal temperatures reduced the odds of infection. ConclusionExposure to cold increases SARS-CoV2 risk, especially on days with moderate to high air pollution. Heated temperatures and moderate to high air pollution during infection may cause PCC. These findings stress the need for mitigation and adaptation strategies for climate change to reduce increasing trends in the frequency of weather extremes that have consequences on air pollution concentrations.

Ambient temperature variations and AIDS-related mortality: A time-stratified case-crossover study in 103 counties, China

BackgroundClimate change, characterized by the steady ascent of global temperatures and the escalating unpredictability of climate patterns, poses multifaceted challenges to public health worldwide. However, vulnerable groups, particularly the population affected by HIV/AIDS, have received little attention. ObjectivesWe aimed to examine the impacts of temperature variations on AIDS-related mortality. MethodsData on individuals with HIV/AIDS were collected from the HIV/AIDS Comprehensive Response Information Management System between 2013 and 2019. Temperature variation metrics were constructed by diurnal temperature range (DTR), temperature changes between neighboring days (TCN), and temperature variability (TV0-t). Time-stratified case-crossover design with conditional logistic regression models was used to investigate the associations between ambient temperature variations and AIDS-related mortality. ResultsEach 1 °C elevated in DTR was linked with a 5.28 % [95 % confidence intervals (CIs): 1.61, 9.08] increment in AIDS-related mortality at a lag of 0–6 days. Stronger associations between DTR and AIDS-related mortality were observed in the married than in single, with corresponding excess ORs (%) of 5.33 (95 % CIs: 0.29, 10.62) versus 4.79 (95 % CIs: −0.50, 10.36) for 1 °C increased in DTR at lag 0–6 days. Additionally, we noticed the impact of DTR was more pronounced in the warm season, leading to a 7.32 % (95 % CIs: 0.57, 14.51) elevation in the risks of AIDS-related mortality for 1 °C increase in DTR at lag 0–6 days, while the effect value decreased to 5.16 % (95 % CIs: 0.71, 9.81) in the cold season. ConclusionsOur findings indicated that DTR might be a significant risk factor for AIDS-related deaths among ambient temperature variation indicators, and underscored the importance of considering temperature variability in public health interventions aimed at mitigating this risk of AIDS-related mortality.

Assessing the short-term effects of PM2.5 and O3 on cardiovascular mortality using high-resolution exposure: a time-stratified case cross-over study in Southwestern China.

Air pollution is a major risk factor of cardiovascular disease (CVD). To date, limited studies have estimated the effects of ambient air pollution on CVD mortality using high-resolution exposure assessment, which might fail to capture the spatial variation in exposure and introduce bias in results. Besides, the three-year action plan (TYAP, 2018-2020) was released; thus, the constitution and health effect of air pollutants may have changed. In this study, we estimated the short-term effect exposed to particulate matters with parameter less than 2.5µm (PM2.5) and ozone (O3) with 0.05° × 0.05° resolution on CVD mortality and measured the influence of TYAP in the associations. We used random forest models with spatial weight matrices to attain high-resolution pollutant concentrations and conditional Poisson regression to assess the relationship between air pollution and cardiovascular mortality. With an increase of 10µg/m3 in PM2.5 and O3 during 2018-2021 in the Sichuan Basin (SCB), CVD mortality increased 1.0134 (95% CI 1.0102, 1.0166) and 1.0083 (95% CI 1.0060, 1.0107), respectively, using high-resolution air pollutant concentration, comparing to 1.0070 (95% CI 1.0052, 1.0087) and 1.0057 (95% CI 1.0037, 1.0078) using data from air quality monitoring stations (AQMs). After TYAP, the relative risk (RR) due to PM2.5 rose up to 1.0149 (95% CI 1.0054, 1.0243), and the RR due to O3 rose up to 1.0089 (95% CI 1.0030, 1.0148) in Sichuan Province. We found significantly positive association of cardiovascular mortality and air pollution in Sichuan Province. And using high-resolution exposure would be more accurate to estimate the effect of air pollution on CVD. After TYAP, the cardiovascular mortality risk estimation due to PM2.5 decreased in elderly in SCB, and the risk due to O3 increased in Sichuan Province.

Short-term exposure to ambient air pollution and injuries due to external causes according to intentions and mechanisms

Although injuries are a leading cause of death and affect the life expectancy of individuals who live with disabilities globally, the potential role of air pollution exposure on injuries due to external causes has received little scientific attention, especially compared with that given to the association of air pollution and non-external causes of morbidity and mortality. We investigated the association between emergency department visits for externally caused injuries and short-term exposure to major ambient air pollutants, with focus on the intentions and mechanisms of injuries. We identified 2,049,855 injured patients in Seoul, South Korea between 2008 and 2016 using the National Emergency Database. Daily short-term exposure to air pollution including particles <10 μm (PM10) and <2.5 μm (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3) was estimated based on hourly concentrations. We employed a time-stratified case-crossover study design using a conditional Poisson regression model adjusted for meteorological variables, influenza epidemics, and holidays. Immediate exposure (lag 0) to most pollutants significantly increased the risk of total injuries (PM2.5, 0.42 %; NO2, 0.68 %; SO2, 1.05 %; CO, 0.57 %; O3, 1.86 % per interquartile range increment), and the associations differed according to the intention and mechanism of injury. Unintentional and assault injuries were significantly associated with air pollution exposure, whereas self-harm injuries showed no association. In mechanism-specific analyses, injuries caused by falls, blunt objects, penetration, traffic accidents, machinery, and slips were associated with specific air pollutants, even in the co-pollutant models. The associations were stronger in injured patients aged <15 years, and in males than in their counterparts. Our results suggest that short-term air pollution exposure might play a role in the risk of externally caused injuries and the association may differ depending on the intention and mechanism of injury, which provide important evidence for injury prevention and air quality strategies.

Associations between Short-Term Exposure to Ambient Air Pollution and Influenza: An Individual-Level Case-Crossover Study in Guangzhou, China.

Influenza imposes a heavy burden on public health. Little is known, however, of the associations between detailed measures of exposure to ambient air pollution and influenza at an individual level. We examined individual-level associations between six criteria air pollutants and influenza using case-crossover design. In this individual-level time-stratified case-crossover study, we linked influenza cases collected by the Guangzhou Center for Disease Control and Prevention from 1 January 2013 to 31 December 2019 with individual residence-level exposure to particulate matter ( and ), sulfur dioxide (), nitrogen dioxide (), ozone () and carbon monoxide (CO). The exposures were estimated for the day of onset of influenza symptoms (lag 0), 1-7 d before the onset (lags 1-7), as well as an 8-d moving average (lag07), using a random forest model and linked to study participants' home addresses. Conditional logistic regression was developed to investigate the associations between short-term exposure to air pollution and influenza, adjusting for mean temperature, relative humidity, public holidays, population mobility, and community influenza susceptibility. eligible cases were identified in our study. Every increase in exposure to , , , and CO and every increase in over 8-d moving average (lag07) was associated with higher risk of influenza with a relative risk (RR) of 1.028 (95% CI: 1.018, 1.038), 1.041 (95% CI: 1.032, 1.049), 1.169 (95% CI: 1.151, 1.188), 1.004 (95% CI: 1.003, 1.006), and 1.134 (95% CI: 1.107, 1.163), respectively. There was a negative association between and influenza with a RR of 0.878 (95% CI: 0.866, 0.890). Our findings suggest that short-term exposure to air pollution, except for , is associated with greater risk for influenza. Further studies are necessary to decipher underlying mechanisms and design preventive interventions and policies. https://doi.org/10.1289/EHP12145.

Association between outdoor temperature and fatal police shootings in the United States, 2015-2021.

Here, we investigate the association between outdoor temperature and fatal police shootings in the United States between 2015 and 2021. We conducted a time-stratified case-crossover study. Data on fatal police shootings were from the Washington Post's Fatal Force database and temperature data were from Daymet. A 5°C increase in maximum same-day temperature was associated with a 1.033 (95% CI = 1.002, 1.065) increased odds of a fatal police shooting. In stratified analyses, the strongest associations were observed in victims who were armed (OR, 1.052 [95% CI = 1.017, 1.088), White (OR, 1.052 [95% CI = 1.006, 1.100), or aged 45+ (OR, 1.110 [95% CI = 1.044, 1.181]). In additional subgroup analyses, relative risks were also generally higher among those who were armed. There is evidence of an association between outdoor temperature and fatal police shootings in the United States, particularly when the victims were reported as armed. This study cannot determine if the associations are a result of any specific causes (e.g., increased police aggression or other factors).

Ambient heat and diabetes hospitalizations: Does the timing of heat exposure matter?

BackgroundAlthough ambient heat exposure is linked with diabetes mortality, the impacts of heat exposure on diabetes-related hospitalizations remain controversial. Previous research did not examine the timing of heat-diabetes associations and relation with comorbidities/risk factors. ObjectiveWe examined the association between heat exposure and diabetes-related hospitalizations in the transitional and summer months and identified populations vulnerable to heat. MethodsWe conducted a time-stratified case-crossover study. Data on diabetes hospital admissions (primary diagnosis of type 1 and type 2 diabetes, 2013–2020) were collected by the New York State (NYS) Department of Health under the state legislative mandate. We treated temperature and air pollutants as continuous variables and defined the heat exposure as per interquartile range (IQR, a measure between the 25th and 75th percentiles) increase of daily mean temperature. Conditional logistic regressions were performed to quantify the heat-diabetes associations after controlling for air pollutants and time variant variables. Multiplicative-scale interactions between heat and demographics/comorbidities/risk factors on diabetes hospitalizations were investigated. ResultsEach IQR increase in temperature was associated with significantly increased risks for diabetes admissions that occurred immediately and lasted for an entire week during multi-day lags in the transitional month of May (ranges of excess risk: 3.1 %–4.8 %) but not in the summer (June–August) (ranges of excess risk: −0.3 %–1.3 %). The significant increases in the excess risk of diabetes were also found among diabetes patients with complications of neuronopathy (excess risk: 27.7 %) and hypoglycemia (excess risk: 19.1 %). Furthermore, the modification effects on the heat-diabetes association were significantly stronger in females, Medicaid enrollees, non-compliant patients, and individuals with comorbidities of atherosclerotic heart disease and old myocardial infarction. ConclusionsAmbient heat exposure significantly increased the burden of hospital admissions for diabetes in transitional rather than summer months indicating the importance of exposure timing. Vulnerability to heat varied by demographics and heart comorbidity.

Increased Risk for Hospitalization Associated with Short Term Particle Air Pollution Exposure for California Residents with Sickle Cell Disease

Background: Air pollution is associated with numerous adverse health outcomes in the general population such as asthma exacerbations, pneumonia, myocardial infarction, and stroke. There is a strong association between air pollution and mechanistic processes associated with oxidative stress, vasoconstriction, and inflammation, suggesting a high risk of exposure for those with sickle cell disease (SCD). A small number of published studies have explored this relationship, primarily focusing on children. Only two studies have examined air pollution in the US, both with outcomes among urban area hospitals in Atlanta, GA. None have taken place in California, which has the worst air quality, including the four most polluted cities in year-round particle pollution in the nation. Additionally, all published studies have overlooked more rural exposure areas. Recent advances in environmental exposure assessment have enabled high-resolution predictions of ambient air pollution concentrations in the whole US, making it possible to cover unmonitored suburban and rural areas that were unrepresented in the past. In addition, these high-resolution predictions are more precise surrogates of the personal exposure measures than monitored data. Particulate matter with a diameter of 2.5 microns or less (PM 2.5) is the most harmful pollutant based on current research findings. We hypothesized that short term increases in PM 2.5 exposure were associated with an increased risk for hospitalization among individuals with SCD in California. Methods: We designed a time-stratified case-crossover study to estimate the percent change in risk for hospitalization for SCD complications associated with each 1mg/m 3 increase in PM 2.5 exposure. The zip code of residence was used to spatially link each hospital admission with PM 2.5 exposure using a novel hybrid exposure model allowing for estimated exposure in areas without direct remote sensing. We used conditional logistic regressions to examine the PM 2.5 exposures at 7-day moving average and single lag days (from lag 0 to 6 days) before admission, adjusting for nonlinear confounding effects of air temperature and humidity at the same exposure window. We examined risk for all hospitalizations and specifically for vaso-occlusive pain (VOC) and acute chest syndrome (ACS). Results: From 2000-2016, among 5,835 California residents with SCD, there were 107,450 admissions for sickle cell disease complications with VOC being the most common indication (71.1%). PM 2.5 air pollution data was examined among 2,634 zip codes throughout the state. Residents with SCD were noted to be living among 1,180 zip codes. The daily burden of PM 2.5 was higher in zip codes with residents with SCD (mean 11.5 mg/m 3, standard deviation [SD] 9.0) when compared to zip codes without residents known to have SCD (mean 9.2 mg/m 3, SD 8.6, p&amp;lt;0.001) ( Table 1). Overall, the mean daily burden of PM 2.5 declined in the period of 2010-2016 when compared to that from 2000-2009. However, the daily mean PM 2.5 concentration remained higher in zip codes with individuals with SCD. No significant association was seen in examining the week-long exposure to PM 2.5 and increase risk in hospitalizations for any indication over the entire study period (2000-2016). However, when examining the more contemporary period of 2010-2016, we identified that each 1mg/m 3 increase in PM 2.5 was associated with 0.22% increased risk for SCD hospitalization (Confidence Interval [CI] 0.02-0.42, p=0.03) 3 days prior to admission. We observed a 0.26% increased risk for hospitalization for VOC with each 1 mg/m 3 increase in PM 2.5 exposure (CI 0.02-0.49, p=0.03) at lag day 3 (Figure 1). No effect was seen with PM 2.5 on hospitalizations for ACS during any time period. Discussion: Our study suggests that short term air pollution exposure may be a trigger for hospitalization for individuals with SCD. In particular this effect is seen in the more recent years with a lower daily average PM 2.5 burden overall, suggesting attention may be needed well below Environmental Protection Agency (EPA) thresholds. Consistent with previous studies, lag day 3 PM 2.5 exposure is associated with an increased risk for hospitalization for VOC. These results may have important implications in understanding risk factors for hospitalization for children and adults with SCD.

Impacts of short-term low-level exposure to air pollutants on hospital admissions for pulmonary sepsis in elderly patients

BackgroundAcute exposures to high levels of air pollutants are thought to be associated with hospitalization of patients with lung infection, while relatively little is known about the association between air pollutants and HOSPITAL ADMISSIONS FOR pulmonary sepsis.ObjectivesTo assess the correlation between low-level exposure to air pollutants and the hospitalizations for pulmonary sepsis in elderly patients.MethodsA total of 249 elderly patients with pulmonary sepsis from January 2018 to December 2020 in Shenzhen people’s hospital were included. The data regarding hospitalizations for pulmonary sepsis, meteorological factors, and daily average levels of air pollutants on single-day lags (Lag0 to Lag7) in Shenzhen were collected. Low-level exposure was defined as the annual means of air pollutants below the levels of the Ambient Air Quality Standard (AAQS) in China (NO. GB3095-2012) and/or Global Air Quality Guidelines (AQG). A time-stratified case-crossover study design approach was used to evaluate the associations between exposure to air pollutants and incidence of the disease, univariate and multivariate logistic regression analysis to analyze the association between levels of air pollutants and hospitalizations for pulmonary sepsis in elderly patients.ResultsExposure to PM1(P = 0.007, Lag 2 day; P = 0.038, Lag6 day), PM2.5(P = 0.046, Lag2 day), PM10(P = 0.048, Lag4 day), and O3(P = 0.044, Lag6 day) was positively correlated with elevated risk of hospitalizations for pulmonary sepsis. In addition, logistic regression analysis revealed that exposure to PM1 (OR = 1.833, 95%CI:1.032 ~ 3.256, Lag6 day) and O3 (OR = 2.091, 95%CI:1.019 ~ 4.289, Lag6 day) were the independent risk factors of pulmonary sepsis in elderly patients.ConclusionOur results demonstrate that short-term low-level exposure to PM1 and O3 could elevate the risk of hospitalizations for pulmonary sepsis in elderly patients in Shenzhen, providing evidence for developing early warning and screening systems for pulmonary sepsis.

Short-term exposure to ambient air pollution and hospital admissions for angina among older adults in South China

Ambient air pollution has been linked to an increased risk of various acute cardiovascular outcomes; however, its effects on hospital admissions for angina are yet to be evaluated. We conducted a time-stratified case-crossover study with conditional logistic regression models among 46,687 adults 60 years or older who were admitted to hospital for angina in Guangzhou, China during 2016–2019 to investigate the association of exposure to ambient particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5), particulate matter with an aerodynamic diameter ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) with hospital admissions for angina. Daily residential air pollutant exposures were extracted from a grid dataset. Each 10 μg/m3 increase of lag 0-day exposure to PM10, SO2, NO2, CO, and O3 was significantly associated with a 0.80% (95% confidential interval: 0.32%, 1.28%), 4.04% (0.34%, 7.89%), 2.47% (1.81%, 3.12%), 0.13% (0.07%, 0.19%), and −0.38% (−0.74%, −0.01%) increase in odds of admission, respectively. The association for NO2 exposure remained stable, while the associations for PM10, SO2, CO, and O3 became insignificant with adjustment for other air pollutants. The association for NO2 exposure was stronger in cool season. We estimated that up to 9.12% of angina admissions were attributable to NO2 exposure. Our findings suggest that ambient NO2 may trigger hospital admissions for angina in Chinese older adults, which highlights the importance to prevent angina by reducing individual NO2 exposures.

Abstract 17485: Risk of Heart Failure Hospitalizations With Exposure to Colder Temperature and Regional Variations Among Older Adults in the United States

Introduction: Extreme cold was associated with excess heart failure (HF) deaths in ecological studies. The relationship between colder temperatures and HF hospitalizations is not well understood. Hypothesis: Lower minimum temperatures (T min ) increase the risk of HF hospitalization among older adults and the impact varies by climate regions. Methods: A time-stratified case-crossover study among adults aged ≥66 hospitalized for HF was conducted using a 20% sample of Medicare data (2008-2019, Nov-Feb). Daily T min from the Parameter-elevation Relationships on Independent Slopes model were linked to Medicare data by zip code of residence. We used bidirectional sampling to select up to 5 controls. We used conditional logistic regression with a restricted cubic spline to model non-linear effects between T min and HF hospitalization in all patients and regional subgroups. Results: Among 529,879 cases (mean age 79, 61% female, 86% white), the risk of HF hospitalization peaked at 4 °F (OR 1.29 [CI 1.28-1.30]) and plateaued over colder T min relative to the median T min (31.5°F). Above 31.5 °F, the risk was reduced by 18% for every 10 °F (Figure 1). This inverse relationship between T min and HF hospitalizations during the winter were most prominent in colder regions (Figure 2). Conclusions: T min ≤4 °F increased the risk of HF hospitalizations by upwards of 29% compared to the national median T min . The plateau at more extreme T min may be due to avoidance of outdoor exposure. A similar behavioral response may occur in warmer regions, whereas some degree of cold exposure is inevitable in colder regions. HF patients should be aware of the risks from exposure to colder temperatures during winter months.