Nationwide Case-crossover Study Research Articles

Heterogeneous associations between short-term ambient ozone exposure and morbidities from infants to seniors: a nationwide case-crossover study in South Korea

Heterogeneous associations between short-term ambient ozone exposure and morbidities from infants to seniors: a nationwide case-crossover study in South Korea

Short-term effects of ambient temperature variability on myocardial infarction hospitalizations in Sweden: A nationwide case-crossover study

Abstract Background Climate change threatens human health and general welfare via multiple dimensions. However, the short-term effect of temperature variability, a crucial aspect of climate change, on myocardial infarction (MI) remains largely unexplored. Purpose We aimed to assess the short-term effects of temperature variability on MI hospitalizations within the nationwide SWEDEHEART registry. Methods This population-based nationwide study involved 228,897 MI patients from the SWEDEHEART registry in Sweden from 2005 to 2019. High-resolution (1 km × 1 km) daily mean ambient temperature was estimated using a spatiotemporal machine learning methodology and assigned to patients’ home addresses. Temperature variability was calculated as the difference between the same-day (as the MI event) ambient temperature and the average temperature recorded over the preceding seven days. Specifically, an upward temperature shift represents a rise in the current day’s temperature relative to the seven-day average, while a downward temperature shift indicates a corresponding decrease. A time-stratified case-crossover design incorporating a conditional logistic regression model with distributed lag non-linear model was applied to estimate the association between ambient temperature variability and total MI, ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). Moreover, we assessed potential effect modification by sex and medication intake. The results were expressed as odds ratio (OR, with their 95% confidence intervals [CIs]) per 1°C increase in temperature variability. Results Our study found that a 1°C increase in upward temperature shift was significantly associated with increased risks for total MI, STEMI, and NSTEMI (OR [95% CI]: 1.010 [1.006-1.015], 1.014 [1.006-1.022], and 1.009 [1.004-1.014], respectively). Furthermore, a 1°C greater in downward temperature shift was significantly associated with decreased risks for total MI and NSTEMI (OR [95% CI]: 0.995 [0.991-0.999], and 0.993 [0.988-0.998], respectively). Moreover, we found that males and patients who were on any heart medication, particularly digitalis, were at a higher risk of MI associated with exposure to higher upward temperature shifts compared to females and their counterparts not taking these medications. Conclusions This nationwide case-crossover study provides novel evidence that short-term exposure to increasing upward temperature shift is associated with an increased risk of MI hospitalization. Our finding highlights the cardiovascular health threats posed by upward temperature shifts, which are anticipated to increase in frequency and intensity due to climate change.

Effects of short-term exposures to lower air temperature and cold spells on myocardial infarction hospital admissions: a nationwide study in Sweden

Abstract Background Exposures to lower air temperature and cold spells have been associated with an increased risk of various diseases. However, the short-term effect of lower air temperature and cold spells on myocardial infarction (MI) remains incompletely understood. Purpose We aimed to evaluate the short-term effects of lower air temperature and cold spells on MI hospital admissions within the nationwide SWEDEHEART registry. Methods This population-based nationwide study included 120,380 MI cases admitted to hospitals in Sweden during the cold season (October to March) from 2005 to 2019. Daily mean air temperature was estimated at 1 km2 spatial resolution across Sweden using a three-stage machine learning approach and percentiles of daily temperatures experienced by individuals in the same municipality were employed as individual exposure indicators to account for potential geographic adaptation. Cold spells were defined as periods of at least two consecutive days with a daily mean temperature below the 10th percentile of the temperature distribution for each municipality. A time-stratified case-crossover design incorporating a conditional logistic regression model with distributed lag non-linear model using lag 0-1 and lag 2-6 days was employed to evaluate the short-term effects of lower air temperature and cold spells on total MI, non-ST-segment elevation MI (NSTEMI) and ST-segment elevation MI (STEMI). Results We found significant increases in risk for total MI, NSTEMI, and STEMI in association with a decrease of one percentile in temperature at a lag of 2-6 days, indicated by ORs (95% CI) of 1.099 (1.057-1.142), 1.110 (1.06-1.164), and 1.076 (1.004-1.153), respectively. Additionally, we found that cold spells were significantly associated with increased risks for total MI, NSTEMI, and STEMI at a lag of 2-6 days, with ORs (95% CI) of 1.077 (1.037-1.12), 1.069 (1.02-1.119), and 1.095 (1.023-1.172), respectively. Moreover, independent effects of lower air temperature and cold spells on MI occurrence were found after adjusting for each other. Conversely, we observed that lower air temperature and cold spells were associated with decreased risks for MI at a lag of 0-1 days. Conclusions This nationwide case-crossover study demonstrated a novel biphasic pattern in MI risk following exposure to lower air temperatures and cold spells, characterized by an initial transient reduction in risk at lags 0-1 day, followed by a significant increase in risk at lags 2-6 days. As climate change continues to induce complex shifts in regional weather patterns, enhancing protections to reduce future cold-related cardiac hospitalizations is crucial.

Increased risk of cardiovascular events in the weeks following hospitalised COPD exacerbations: the EXACOS-CV French nationwide case-crossover study

Abstract Introduction Previous studies indicate that in people living with chronic obstructive pulmonary disease (COPD), the risk of myocardial infarction (MI), heart failure (HF) decompensation, arrhythmias and ischemic stroke increases following a COPD exacerbation. This association has not been explored for detailed types of cardiovascular events (CVE), namely for different types of myocardial infarction. Objective To quantify the risk of CVE following a COPD exacerbation overall, and by detailed type of CVE. Methods A case-crossover study was conducted using the French national hospital discharge database (Programme de Médicalisation des Systèmes d'Information, PMSI). Case-patients: (i) were aged≥40 years with a COPD diagnosis; (ii) hospitalised in 2018-2019 for CVE; (iii) experienced the CVE within 24 weeks of a hospitalised exacerbation of COPD. Hospitalisation date for CVE was index date. Conditional logistic regression models estimated the association between a hospitalised exacerbation and CVE (overall and by type of CVE) – expressed as odds ratios (OR) – comparing the odds of a hospitalised COPD exacerbation during the risk period (4 weeks prior to index date) versus control periods (9-24 weeks prior to index date). Results Among 122,172 patients with COPD hospitalised for a severe CVE in 2018-2019, 9,840 (8%) had a hospitalised exacerbation of COPD in the prior 24 weeks and qualified as case-patients. Mean age was 76.8 years (SD 10.7); 6,496 (66%) were male. The most frequent CVE were decompensated heart failure (n=5,888, 60%) and acute coronary syndrome (n=1,070, 11%); in-hospital death in the 24 weeks following an exacerbation of COPD occurred in 950 (10%) patients. Median time elapsed between hospitalised exacerbation and CVE (any type) was 43 days (Figure 1); the shortest delays were observed for non-STEMI (24 days) and resuscitated cardiac arrest (28 days). Risk of CVE in the 4 weeks following a hospitalised COPD exacerbation was 3-times the risk in the 9-24 weeks post-exacerbation (OR 3.0; 95%CI 2.9-3.2 – Figure 2). This increase in risk was observed for each individual type of CVE. The highest effect size was observed for non-STEMI (OR 5.3; 95%CI 4.5-6.3). Conclusion The risk of CVE substantially increases following a hospitalised exacerbation of COPD overall and for all types of CVE (acute ischemic events, arrhythmias, and heart failure decompensation). The first month following a hospitalised exacerbation is a period of vulnerability for people living with COPD, with some variability in the magnitude and temporality of risk increase according to the type of CVE. These results stress the need for immediate and sustained monitoring of exacerbating COPD patients to prevent a subsequent severe cardiac event. In addition, exacerbations prevention is an essential target of COPD treatment.

Weather conditions and legionellosis: a nationwide case-crossover study among Medicare recipients.

Legionellosis is a respiratory infection caused by Legionella sp. that is found in water and soil. Infection may cause pneumonia (Legionnaires' Disease) and a milder form (Pontiac Fever). Legionella colonizes water systems and results in exposure by inhalation of aerosolized bacteria. The incubation period ranges from 2 to 14 days. Precipitation and humidity may be associated with increased risk. We used Medicare records from 1999 to 2020 to identify hospitalizations for legionellosis. Precipitation, temperature, and relative humidity were obtained from the PRISM Climate Group for the zip code of residence. We used a time-stratified bi-directional case-crossover design with lags of 20 days. Data were analyzed using conditional logistic regression and distributed lag non-linear models. A total of 37883 hospitalizations were identified. Precipitation and relative humidity at lags 8 through 13 days were associated with an increased risk of legionellosis. The strongest association was precipitation at day 10 lag (OR = 1.08, 95% CI = 1.05-1.11 per 1 cm). Over 20 days, 3 cm of precipitation increased the odds of legionellosis over four times. The association was strongest in the Northeast and Midwest and during summer and fall. Precipitation and humidity were associated with hospitalization among Medicare recipients for legionellosis at lags consistent with the incubation period for infection.

Short-Term Effects of Lower Air Temperature and Cold Spells on Myocardial Infarction Hospitalizations in Sweden

BackgroundLower air temperature and cold spells have been associated with an increased risk of various diseases. However, the short-term effect of lower air temperature and cold spells on myocardial infarction (MI) remains incompletely understood. ObjectivesThe purpose of this study was to investigate the short-term effects of lower air temperature and cold spells on the risk of hospitalization for MI in Sweden. MethodsThis population-based nationwide study included 120,380 MI cases admitted to hospitals in Sweden during the cold season (October to March) from 2005 to 2019. Daily mean air temperature (1 km2 resolution) was estimated using machine learning, and percentiles of daily temperatures experienced by individuals in the same municipality were used as individual exposure indicators to account for potential geographic adaptation. Cold spells were defined as periods of at least 2 consecutive days with a daily mean temperature below the 10th percentile of the temperature distribution for each municipality. A time-stratified case-crossover design incorporating conditional logistic regression models with distributed lag nonlinear models using lag 0 to 1 (immediate) and 2 to 6 days (delayed) was used to evaluate the short-term effects of lower air temperature and cold spells on total MI, non–ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). ResultsA decrease of 1-U in percentile temperature at a lag of 2 to 6 days was significantly associated with increased risks of total MI, NSTEMI, and STEMI, with ORs of 1.099 (95% CI: 1.057-1.142), 1.110 (95% CI: 1.060-1.164), and 1.076 (95% CI: 1.004-1.153), respectively. Additionally, cold spells at a lag of 2 to 6 days were significantly associated with increased risks for total MI, NSTEMI, and STEMI, with ORs of 1.077 (95% CI: 1.037-1.120), 1.069 (95% CI: 1.020-1.119), and 1.095 (95% CI: 1.023-1.172), respectively. Conversely, lower air temperature and cold spells at a lag of 0 to 1 days were associated with decreased risks for MI. ConclusionsThis nationwide case-crossover study reveals that short-term exposures to lower air temperature and cold spells are associated with an increased risk of hospitalization for MI at lag 2 to 6 days.

Effects of extreme weather conditions on heart disease: nation-wide case-crossover study in Japan

Effects of extreme weather conditions on heart disease: nation-wide case-crossover study in Japan

Air Pollution Exposure and Atrial Fibrillation Hospitalizations: A Nationwide Case-Crossover Study in Israel

Air Pollution Exposure and Atrial Fibrillation Hospitalizations: A Nationwide Case-Crossover Study in Israel

Mortality risk and burden of sudden cardiac arrest associated with hot nights, heatwaves, cold spells, and non-optimum temperatures in 0.88 million patients: An individual-level case-crossover study

Sudden cardiac arrest (SCA) is a global health concern, imposing a substantial mortality burden. However, the understanding of the impact of various extreme temperature events, when accounting for the effect of daily average temperature on SCA, remains incomplete. Additionally, the assessment of SCA mortality burden associated with temperatures from an individual-level design is limited. This nationwide case-crossover study collected individual SCA death records across all (2844) county-level administrative units in the Chinese Mainland from 2013 to 2019. Four definitions for hot nights and ten for both cold spells and heatwaves were established using various temperature thresholds and durations. Conditional logistic regression models combined with distributed lag nonlinear models were employed to estimate the cumulative exposure-response relationships. Based on 887,662 SCA decedents, this analysis found that both hot nights [odds ratio (OR): 1.28; attributable fraction (AF): 1.32 %] and heatwaves (OR: 1.40; AF: 1.29 %) exhibited significant added effects on SCA mortality independent of daily average temperatures, while cold spells were not associated with an elevated SCA risk after accounting for effects of temperatures. Cold temperatures [below the minimum mortality temperature (MMT)] accounted for a larger mortality burden than high temperatures (above the MMT) [AF: 12.2 % vs. 1.5 %]. Higher temperature-related mortality risks and burdens were observed in patients who experienced out-of-hospital cardiac arrest compared to those with in-hospital cardiac arrest. This nationwide study presents the most compelling and comprehensive evidence of the elevated mortality risk and burden of SCA associated with extreme temperature events and ambient temperatures amid global warming.

Use of fluoroquinolones and the risk of aortic and mitral regurgitation: A nationwide case-crossover study.

Recently, there have been conflicting results reporting an increased risk of AR or MR associated with oral fluoroquinolones (FQs).This study investigated whether the use of FQs increases the risk of mitral regurgitation (MR) or aortic regurgitation (AR). A retrospective cohort study was conducted by using the Taiwan National Health Insurance research database. A unidirectional case-crossover design without selecting controls from an external population was adopted in this study. A total of 26,650 adult patients with new onset of AR or MR between January 1, 2000, and December 31, 2012, were identified. The risk of outcomes was compared between the hazard period and one of the randomly selected referent periods of the same individuals. Before exclusion of pneumonia diagnosed within 2 months before the index date, patients who took FQs had a significantly greater risk of AR or MR (adjusted odds ratio [aOR] 1.51, 95% confidence interval [CI] 1.30-1.77), any AR (combined AR and MR) (aOR 1.50, 95% CI 1.10-2.04), and any MR (combined AR and MR) (aOR 1.37, 95% CI 1.16-1.62). After exclusion of pneumonia, FQs exposure remained significantly associated with a greater risk of MR (aOR 1.38, 95% CI 1.17-1.62) and any MR (aOR 1.25, 95% CI 1.05-1.48). The findings suggested that patients treated with FQs could be warned about the potential risk for MR even after considering the possibility of protopathic bias. Reducing unnecessary FQs prescriptions may be considered to reduce the risk of valvular heart disease.

Air pollution and acute kidney injury with comorbid disease: A nationwide case-crossover study in South Korea

Emerging evidence suggests that air pollution is a significant contributor to the global burden of kidney disease. Although acute kidney injury (AKI) is a common secondary event in ill patients, evidence regarding the association between air pollution and AKI accompanied by specific comorbidities is limited. This study aimed to estimate the association between short-term exposure to air pollution (fine particulate matter ≤2.5 μm [PM2.5] and ozone [O3]) and incident AKI by comorbid diseases using the Korea National Health Information Database (NHID). Total of 160,390 incident AKI cases, defined as an emergency department (ED) visit due to AKI, were observed within the period 2015–2021 in inland South Korea. A time-stratified case-crossover design was applied for PM2.5 and O3 individually, using a conditional logistic regression model within each case and its own control (three or four days of the same day of the week in the same month) to estimate the association between short-term air pollution exposure and ED visits due to AKI. Short-term exposure to PM2.5 and O3 was associated with ED visits due to AKI with ORs of 1.008 (95% confidence interval [CI]: 0.999, 1.017) and 1.019 (95% CI: 1.005, 1.033) for an interquartile range (IQR) increase in lag 0–1 day PM2.5 and O3 respectively, although OR for PM2.5 was marginally significant. The odds of incident AKI associated with PM2.5 was evident in conjunction with ischemic heart disease, cerebrovascular disease, gastrointestinal bleeding, and pneumonia. For O3, the estimated odds was prominent for AKI with ischemic heart disease. In addition, the comorbid disease-specific odds of AKI attributed to air pollution varied by sex and age. Our findings provide epidemiological evidence of a plausible mechanism between air pollution and incident AKI and suggest the need for personalized AKI prevention strategies attributed to air pollution.

Short-term ozone exposure and cancer mortality in Brazil: A nationwide case-crossover study.

Exposure to ambient ozone (O3) is linked to increased mortality risks from various diseases, but epidemiological investigations delving into its potential implications for cancer mortality are limited. We aimed to examine the association between short-term O3 exposure and site-specific cancer mortality and investigate vulnerable subgroups in Brazil. In total 3,459,826 cancer death records from 5570 Brazilian municipalities between 2000 and 2019, were included. Municipal average daily O3 concentration was calculated from a global estimation at 0.25°×0.25° spatial resolution. Thetime-stratified case-crossover design was applied to assess the O3-cancer mortality association. Subgroup analyses by age, sex, season, time-period, region, urban hierarchy, climate classification, quantiles of GDP per capita and illiteracy rates were performed. A linear and non-threshold exposure-response relationship was observed for short-term exposure to O3 with cancer mortality, with a 1.00% (95% CI: 0.79%-1.20%) increase in all-cancer mortality risks for each 10-μg/m3 increment of three-day average O3. Kidney cancer was most strongly with O3 exposure, followed by cancers of the prostate, stomach, breast, lymphoma, brain and lung. The associated cancer risks were relatively higher in the warm season and in southern Brazil, with a decreasing trend over time. When restricting O3 concentration to the national minimum value during 2000-2019, a total of 147,074 (116,690-177,451) cancer deaths could be avoided in Brazil, which included 17,836 (7014-28,653) lung cancer deaths. Notably, these associations persisted despite observed adaptation within the Brazilian population, highlighting the need for a focus on incorporating specific measures to mitigate O3 exposure into cancer care recommendations.

Impacts of medication adherence and home healthcare on the associations between polypharmacy and the risk of severe hypoglycemia among elderly diabetic patients in Taiwan from 2002 to 2012: A nationwide case-crossover study

AimTo assess how medication adherence and home healthcare support influence the role of polypharmacy in induced hypoglycemia events among elderly diabetic patients. MethodsThis case-crossover study retrieved records on diabetic patients >=65 years with severe hypoglycemia from 2002 to 2012 in Taiwan. Case period defined as 1–3 days before severe hypoglycemia was compared with a preceding control period of the same length, with an all-washout period of 30 days. Moreover, the modifiable effects of medication adherence and home healthcare service use were evaluated by stratified analysis. ResultsTotally 2,237 patients were identified. Polypharmacy use was associated with the risk of severe hypoglycemia. Patients receiving polypharmacy without home healthcare services (aOR: 1.34; 95 % CI: 1.16–1.54) and those with poor adherence to anti-diabetic medications (aOR: 1.48; 95 % CI: 1.24–1.77) were significantly associated with an elevated risk of severe hypoglycemia. In patients with good adherence, non-home healthcare users being prescribed with polypharmacy had a higher risk of severe hypoglycemia. In the group that received home healthcare services, patients with poor adherence using polypharmacy had a higher risk of severe hypoglycemia. ConclusionsGood adherence and receiving home healthcare services were associated with a decreased odds of severe hypoglycemic events in elderly diabetic patients, regardless of the fact whether they were prescribed with polypharmacy.

Ambient Air Particulate Matter and Hospital Admissions for Chronic Kidney Disease in China: A Nationwide Case-Crossover Study.

Incident chronic kidney disease (CKD) may be accelerated (could be indicated by repeated admissions to the hospital) by environmental triggers such as ambient particulate matter (PM). Additionally, hospital admission is a sensitive proxy reflecting the disease burden. However, the association of PM exposure with hospital admissions for CKD is still unknown, let alone the excess risks (ERs) in hospital admissions for CKD due to high PM level exposure. In this study, a two-stage time-stratified case-crossover study was conducted to investigate the association of ambient air PM exposure with hospital admission for CKD in 282 Chinese cities of prefecture-level or above during 2013-2017. City-specific associations of single and cumulative 0-3 days lagged exposure to fine particulate matter (PM2.5) and inhalable particles (PM10) with hospital admissions for total CKD and its subtypes were evaluated by the conditional logistic regression model, then were pooled using the random-effect model. A total of 3,490,416 hospital admissions for CKD were identified. We found that per interquartile range (IQR) increment in PM2.5 at lag02 and per IQR increment in PM10 at lag03 were associated with increases of 2.36% (95%CI: 1.58%, 3.14%) and 2.87% (95% CI:1.91%, 3.85%) in hospital admissions for total CKD, respectively. Compared to control concentrations (PM2.5: 35 μg/m3; PM10: 50 μg/m3), the largest ERs in hospital admissions for total CKD were 2.63% (95% CI: 2.15%-3.11%) and 4.45% (95% CI: 3.85%-5.06%) in association with exposure to heavily excessive PM2.5 (≥75 μg/m3) and PM10 (≥150 μg/m3), respectively. Moreover, the attributable fractions (AFs) for CKD admissions were 2.83% for PM2.5 and 3.46% for PM10 during the study period. These findings suggested that exposure to PM2.5 and PM10 is associated with substantially increased risk and burden of CKD admissions.

Cardiovascular safety of using non-steroidal anti-inflammatory drugs for gout: a Danish nationwide case-crossover study.

Gout attacks are treated with uric-lowering and anti-inflammatory drugs. In patients with gout, non-steroidal anti-inflammatory drugs (NSAIDs) could be both cardiovascular beneficial, due to their anti-inflammatory actions, and cardiovascular hazardous, due to their prothrombotic, hypertensive, and proarrhythmic side effects. We, therefore, examined the risk of cardiovascular events associated with NSAID use in patients with gout. We conducted a nationwide, population-based case-crossover study of all Danes ≥ 18years of age with first-time gout during 1997-2020, who experienced a cardiovascular event (myocardial infarction, ischemic stroke, congestive heart failure, atrial fibrillation/flutter, or cardiovascular death) (n = 59,150). The exposure was use of NSAIDs, overall and according to type (ibuprofen, naproxen, or diclofenac). We used the dates 300, 240, 180, and 120 before the outcome date as reference dates. We used the Mantel-Haenszel method to calculate odds ratios (ORs) with 95% confidence intervals (CIs) of the association between NSAID use and cardiovascular events. NSAID use was overall associated with 12% decreased odds of a cardiovascular event (OR = 0.88, 95% CI: 0.85-0.91). This decreased odds ratio was observed for the use of ibuprofen (OR = 0.92, 95% CI: 0.88-0.97) and naproxen (OR = 0.85, 95% CI: 0.74-0.97), but not for the use of diclofenac (OR = 0.97, 95% CI: 0.90-1.05).Overall, use of NSAIDs was associated with decreased odds of all the individual components of the composite outcome. NSAIDs were not associated with an increased cardiovascular event rate when used in gout patients.Ibuprofen and naproxen appeared to have better cardiovascular risk profiles than diclofenac.

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.

Short-term effects of ambient temperature on acute exacerbation of inflammatory bowel disease: A nationwide case-crossover study with external validation.

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disorder characterized by chronic and relapsing manifestations. Several environmental factors are known as triggers for exacerbation of IBD. However, an association between exacerbation of IBD and ambient temperature is uncertain. This study aimed to estimate the risk of acute exacerbation of IBD due to ambient temperature. We performed a bidirectional case-crossover study using a nationwide claim data from South Korea. The external validation was conducted with a large prospective cohort in the United Kingdom. We confirmed significant associations between acute exacerbation of IBD and the short-term ambient temperature changes toward severe temperatures, in the cold weather (-19.4°C-4.3°C) (odd ratio [OR] = 1.13, 95% confidence interval [CI]: 1.13-1.14) and in the hot weather (21.3°C-33.5°C) (OR = 1.16, 95% CI: 1.15-1.17). However, the association was not significant in the moderate weather (4.3°C-21.3°C). The external validation suggested consistent results with additional elevation of acute exacerbation risk in the colder weather (-13.4°C to 2.6°C) (OR = 1.90, 95% CI: 1.62-2.22) and in the hotter weather (15.7°C-28.4°C) (OR = 1.41, 95% CI: 1.32-1.51). We observed and validated that the short-term ambient temperature changes were associated with acute exacerbation of IBD in the cold and hot weathers. Our findings provide evidence that temperature changes are associated with the acute exacerbation of IBD.

Association between air temperature and unintentional drowning risk in the United Kingdom 2012–2019: A nationwide case-crossover study

ObjectiveDrowning is a leading cause of death. The World Health Organization (WHO) and United Nations (UN) emphasise the need for population-level data-driven approaches to examine risk factors to improve water safety policies. Weather conditions, have the potential to influence drowning risk behaviours as people are more likely to spend time around water and/or undertake risky activities in aquatic spaces as a behavioural thermoregulatory response (e.g., seeking coolth). MethodsA case-crossover approach assessed associations between changes in daily maximum air temperature (data from the nearest weather station to each drowning event) and unintentional drowning risk using anonymous data from the validated UK Water Incident Database 2012–2019 (1945 unintentional deaths, 82% male). Control days were selected using a unidirectional time-stratified approach, whereby seven and 14 days before the hazard day were used as the controls. ResultsMean maximum air temperature on case and control days was 15.36 °C and 14.80 °C, respectively. A 1 °C increase in air temperature was associated with a 7.2% increase in unintentional drowning risk. This relationship existed for males only. Drowning risk was elevated on days where air temperature reached 15–19.9 °C (Odds Ratio; OR: 1.75), 20–24.9 °C (OR: 1.87), and ≥ 25 °C (OR: 4.67), compared with days <10 °C. The greatest elevations in risk appeared to be amongst males and when alcohol intoxication was suspected. Precipitation showed no significant association with unintentional drowning risk. ConclusionsIdentifying such relationships highlights the value of considering weather conditions when evaluating environmental risk factors for drowning, and may inform water safety policy and allocating resources to prevention and rescue.

Cardiovascular safety of non-steroidal anti-inflammatory drug use for gout: A Danish nationwide case-crossover study

Abstract Background Gout is associated with increased cardiovascular risk through inflammation and shared risk factors. Gout attacks are treated with a uric-lowering drug, such as allopurinol, and an anti-inflammatory drug, such as a non-steroidal anti-inflammatory drug (NSAID). Thus, NSAIDs could be both cardiovascular beneficial, due to their anti-inflammatory actions, and cardiovascular hazardous, due to their prothrombotic, hypertensive, and proarrhythmic actions. Yet, no study has examined the cardiovascular safety of NSAIDs for the treatment of gout. Purpose To examine the risk of major adverse cardiovascular events (MACEs) associated with NSAID use in gout patients. Methods We conducted a nationwide, population-based case-crossover study of all Danes ≥18 years of age with first-time gout during 1997–2020, who experienced a MACE (myocardial infarction, ischemic stroke, congestive heart failure, atrial fibrillation or flutter, or all-cause death) (n=103,522). The patients were identified either via a hospital diagnosis for gout (12%) or via a filling of an allopurinol prescription (88%). The exposures were use of NSAIDs overall and according to subtype (ibuprofen, naproxen, or diclofenac). An individual was considered exposed from the time of a filled prescription until the end of a use period, estimated from average use of two tablets per day. In the case-crossover design, we used four reference dates at 120, 180, 240, and 300 days before the outcome. An individual was considered exposed if the use period covered a reference date or the outcome date. We used the Mantel-Haenszel method to calculate odds ratios (ORs) with 95% confidence intervals (CIs) of the association between NSAID use and MACE. Results NSAID use was overall associated with a 15% decreased risk of MACE (OR=0.85, 95% CI: 0.83–0.87). The ORs of the association between NSAID use and the individual cardiovascular events were 0.91 (95% CI: 0.84–0.99) for myocardial infarction, 0.88 (95% CI: 0.81–0.95) for ischemic stroke, 0.89 (95% CI: 0.83–0.94) for congestive heart failure, 0.80 (95% CI: 0.75–0.85) for atrial fibrillation or flutter, and 0.77 (95% CI: 0.75–0.80) for all-cause death. The decreased risk of MACE was observed for use of ibuprofen (OR=0.91, 95% CI: 0.88–0.95) and naproxen (OR=0.78, CI: 0.70–0.86), but not for use of diclofenac (OR=1.03, 95% CI: 0.97–1.09). Conclusions In patients with first-time gout, use of ibuprofen and naproxen was associated with a slightly decreased cardiovascular risk, whereas diclofenac was not.

Short-Term Ambient Air Pollution Exposure and Risk of Out-of-Hospital Cardiac Arrest in Sweden: A Nationwide Case-Crossover Study.

Background Air pollution is one of the main risk factors for cardiovascular disease globally, but its association with out-of-hospital cardiac arrest at low air pollution levels is unclear. This nationwide study in Sweden aims to investigate if air pollution is associated with a higher risk of out-of-hospital cardiac arrest in an area with relatively low air pollution levels. Methods and Results This study was a nationwide time-stratified case-crossover study investigating the association between short-term air pollution exposures and out-of-hospital cardiac arrest using data from the SRCR (Swedish Registry for Cardiopulmonary Resuscitation) between 2009 and 2019. Daily air pollution levels were estimated in 1×1-km grids for all of Sweden using a satellite-based machine learning model. The association between daily air pollutant levels and out-of-hospital cardiac arrest was quantified using conditional logistic regression adjusted for daily air temperature. Particulate matter <2.5 μm exposure was associated with a higher risk of out-of-hospital cardiac arrest among a total of 29 604 cases. In a multipollutant model, the association was most pronounced for intermediate daily lags, with an increased relative risk of 6.2% (95% CI, 1.0-11.8) per 10 μg/m3 increase of particulate matter <2.5 μm 4 days before the event. A similar pattern of association was observed for particulate matter <10 μm. No clear association was observed for O3 and NO2. Conclusions Short-term exposure to air pollution was associated with higher risk of out-of-hospital cardiac arrest. The findings add to the evidence of an adverse effect of particulate matter on out-of-hospital cardiac arrest, even at very low levels below current regulatory standards.