Conditional Poisson Regression Research Articles

Impact of COVID-19 disease and COVID-19 vaccinations on hospital admissions for neurological diseases in the Lombardia over-12 population. Data from a self-controlled case series analysis.

The influence of COVID19 vaccination on the risk of different neurological diseases has been subject of intense investigation. No large scale results have been published so far in the population of around 10 million people of Lombardia in Italy. Linkable administrative health databases from the Lombardia region were used. By using the adapted self controlled case series (SCCS) method for event dependent exposures, we estimated the relative incidence of different neurological diseases following pre-specified windows at risk after vaccination and after COVID-19 infection in the over-12 population of Lombardia. Follow-up time before vaccination (Pre-Vax period) was compared with follow-up time 0-28days (high-risk period) from the day of vaccination as well as for COVID infection. The SCCS model was fitted using a conditional Poisson regression model to estimate the relative incidences (RI) and their 95% Confidence Intervals (CI). The 28-day post-vaccination period was associated with a significant increase in the occurrence of ischemic stroke, cerebral haemorrhage, TIAs and myelitis (IRR 1.44, 1.50, 1.67 and 2.65 respectively). When the risk conferred by COVID19 infection was assessed in the same cohort, significant IRR were greater in the occurrence of ischemic stroke, cerebral haemorrhage, and TIAs (IRR 5.6, 3.62, 6.83) and includes also Multiple Sclerosis, neuromyelitis, and polymyositis (5.25, 8.81, 5.67). Our data suggest that the increased risk of non-inflammatory CNS disorders following COVID-19 vaccination is lower than the risk conferred by COVID-19 infection, and that COVID-19 infection increases the risk of some inflammatory and non inflammatory neurological disorders.

Increased Emergency Department Medical Imaging: Association with Short-Term Exposures to Ambient Heat and Particulate Air Pollution.

Background Climate change adversely affects human health, resulting in higher demand for health care services. However, the impact of climate-related environmental exposures on medical imaging utilization is currently unknown. Purpose To determine associations of short-term exposures to ambient heat and particulate air pollution with utilization of emergency department medical imaging. Materials and Methods In this retrospective time-stratified case-crossover study, daily imaging utilization counts from four emergency departments were linked to local daily environmental data-including fine particulate matter with 2.5-µm or smaller aerodynamic diameter (PM2.5) and ambient temperature-over 10 years (January 2013 to December 2022). Conditional Poisson regression models were used to evaluate the associations between daily imaging utilization and environmental exposures on the same day and each of the 7 days preceding imaging, lag days 0-7, controlling for day of the week, month, and year. Moving averages of mean daily PM2.5 and temperature were calculated to account for lagged exposure effects. Imaging counts were also stratified by modality (CT, radiography, US, and MRI). Results In an analysis of 1 666 420 emergency department imaging studies, a rise of 10 °C in the 2-day moving average of mean daily temperature and a rise of 10 μg/m3 in the 3-day moving average of mean daily PM2.5 were associated with overall imaging utilization increases of 5.1% (incidence rate ratio [IRR], 1.051; 95% CI: 1.045, 1.056) and 4.0% (IRR, 1.040; 95% CI: 1.035, 1.046), respectively. Heat exposure days (mean temperature >20 °C) and air pollution exposure days (mean PM2.5 >12 μg/m3) were associated with same-day excess absolute risk of 5.5 and 6.4 imaging studies per 1 million people at risk per day, respectively. Heat exposure days and air pollution exposure days were associated with increased utilization of radiography (excess relative risk, 2.7% [P < .001] and 2.1% [P < .001], respectively) and CT (excess relative risk, 2.0% [P = .001] and 2.7% [P < .001]) but not US (P = .14 and P = .14) or MRI (P = .70 and P = .65). Conclusion Short-term exposures to ambient heat and particulate air pollution were associated with increased utilization of radiography and CT but not US or MRI. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Vosshenrich in this issue.

Symptomatic patients without coronary artery disease do not have excess cardiovascular risk compared to the general population

Abstract Background Patients with stable angina with no coronary atherosclerosis by coronary computed tomography angiography (CCTA) have a lower cardiovascular risk compared to CCTA patients with greater atherosclerotic burden. However, it remains unknown whether these symptomatic patients have excess cardiovascular risk when compared to the general population and if any excess risk is sex or age dependent. Purpose To examine the 10-year cardiovascular risk and mortality in patients with no coronary atherosclerosis by CCTA compared to a matched general population comparison cohort. Methods We included every symptomatic CCTA patient with no coronary artery disease (CAD), defined as no coronary plaques and Agatston calcium score of 0, in Western Denmark from 2008-2021. Each patient was matched by age and sex with 5 individuals with no previous history of ischemic heart disease from the Western Danish general population. Maximum follow-up was 10 years. Outcomes were myocardial infarction, ischemic stroke, and all-cause death. We estimated 10-year risk difference (RD) and incidence rate ratios (IRR) using a conditional Poisson regression, comparing patients with no CAD to the general population cohort. Additionally, we performed age- (&amp;lt;45 year, 45-65 years, and ≥65 years) and sex stratified analyses. Results We included 39,223 patients with no CAD who were matched with 196,115 individuals from the general population. Median age was 54 and 60% were women. Baseline use of anti-thrombotic agents, statins, and anti-hypertensive drugs was higher in patients with no CAD than the general population. Median follow-up was 6.1 years. CCTA patients with no CAD had lower risk of myocardial infarction [RD -0.2%, IRR 0.75 (95% CI 0.65-0.85)] and death [RD -3.3%, IRR 0.51 (95% CI 0.48-0.55)], but similar risk of ischemic stroke [RD 0.0%, IRR 0.93 (95% CI 0.84-1.02)] compared to the general population (Figure 1). However, patients &amp;lt;45 years had higher 10-year risk of both myocardial infarction and ischemic stroke despite absence of CAD by CCTA compared the general population (Figure 2). Conclusions Symptomatic patients without CAD by CCTA do not have excess cardiovascular risk when compared to a general population cohort without known ischemic heart disease. Future cardiovascular risk management of these patients should therefore follow primary prevention guidelines. However, patients &amp;lt;45 years did exhibit higher risk of ischemic outcomes and may require intensified preventative treatment.Figure 1Figure 2

The interactive effect of extreme weather events and PM2.5 on respiratory health among the elderly: a case-crossover study in a high-altitude city.

With climate change posing increasing threats and aging populations, understanding the complex relationship between extreme temperatures, PM2.5 pollution, and respiratory health among the elderly is crucial. While some research exists, there remains a significant gap in studying the combined effects of heat waves, cold spells, and PM2.5 on elderly respiratory health in high-altitude regions. We collected data from Xining (2016-2021), including respiratory disease outpatient visits, meteorological, and pollutant data. Employing a case-crossover design and conditional Poisson regression analysis, we investigated the individual and interactive impacts of heat wave, cold spell, and PM2.5 on outpatient visits for respiratory disease among the elderly. We used the relative excess odds due to interaction (REOI), proportion attributable to interaction (AP), and synergy index (S) as quantitative indicators of interaction. Our analysis revealed significant associations between heat wave, cold spell, PM2.5 exposure, and outpatient visits for respiratory disease among the elderly, with odds ratios of 1.10 (95%CI: 1.06, 1.15) and 1.16 (95%CI: 1.13, 1.20), respectively. Moreover, a synergistic effect between cold spell and PM2.5 was observed, particularly affecting vulnerable groups such as female and those aged ≥ 80. The combined exposure to cold spell and elevated PM2.5 levels was estimated to contribute to up to 0.18 (95%CI: 0.17, 0.27) of respiratory outpatient visits. This study underscores the need for urgent interventions, such as reducing PM2.5 exposure and enhancing extreme weather warning systems, to protect the respiratory health of the elderly, especially in high-altitude regions.

Risk of major adverse cerebro-cardiovascular events following BNT162b2, CoronaVac, and ChAdOx1 vaccination and SARS-CoV-2 infection: A self-controlled case-series study

ObjectiveTo assess the potential risk of major adverse cerebro-cardiovascular events (MACCE) associated with COVID-19 vaccination and SARS-CoV-2 infection. MethodsThis self-controlled case series study used nationwide health database from Malaysia. The study included individuals aged ≥18 years who were hospitalised between 24 February 2021 and 30 June 2022. Outcomes were composite of MACCE: stroke, acute ischaemic heart disease, and cardiovascular death. Exposures were COVID-19 vaccination and SARS-CoV-2 infection. The risk period was day 1 to day 21 following exposure. Conditional Poisson regression model was used to estimate the incidence rate ratios (IRRs) and 95 % confidence interval (CI) comparing the outcomes in the risk and control periods. ResultsThe risk of MACCE within 21 days after vaccination per 100,000 doses administered were 12.0 (95% CI 11.9–12.1) (BNT162b2), 9.2 (95% CI 9.1–9.3) (CoronaVac), and 6.8 (95% CI 6.6–7.0) (ChAdOx1). The incidence rate ratios showed no increased risk of MACCE associated with the first, second, or third doses of BNT162b2, CoronaVac, and ChAdOx1 vaccines for individuals without prior cardiovascular disease (CVD). This finding was consistent for individuals with CVD. Vaccine booster dose, whether in a homologous or heterologous schedule, did not show increased risk of MACCE. Analysis by ethnic groups detected a slightly elevated risk of MACCE in Indian after the first dose of ChAdOx1 (IRR 1.64; 95% CI 1.08–2.48) in those without CVD. No significant association were observed in other subgroup analyses. SARS-CoV-2 infection was associated with significantly increased risk of MACCE in individuals without CVD (IRR 3.54; 95% CI 3.32–3.76) and with CVD (IRR 1.98; 95% CI 1.61–2.34). ConclusionsOur findings support the favourable safety profile of these COVID-19 vaccines and indicate that the overall benefit-risk ratio of the COVID-19 vaccines remains positive.

Risk of osteoporotic fractures in menopausal women with common mental health diagnoses prescribed SSRIs/SNRIs: cohort and self-controlled case series analyses

SummaryIn a population-based cohort study of menopausal women with common mental health diagnoses, SSRIs/SNRIs were associated with a 32% increased risk of osteoporotic fractures. The risk of osteoporotic fractures was particularly increased for longer periods of treatment with SSRIs/SNRIs (> 5 years) and in younger menopausal women (< 50 years old).PurposeTo investigate the association between selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) and the risk of osteoporotic fractures (OF) in menopausal women with common mental health diagnoses (CMHD).MethodsWe conducted the study with two designs (cohort and self-controlled case series [SCCS]), using the IQVIA Medical Research Database (IMRD) UK. The source population comprised women aged ≥ 50 years and women with a record indicating menopause (< 50 years). All women had a recorded CMHD. For the cohort analysis, the risk of OFs was estimated by comparing women prescribed SSRIs/SNRIs (exposed) to those not exposed. Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (CIs). For the SCCS, women acted as their own controls; periods of exposure to SSRIs/SNRIs were compared to periods of non-exposure using conditional Poisson regression to estimate incidence rate ratios (IRR) with 95% CIs.ResultsWe identified 292,848 women, of whom 35,222 experienced OFs within a median follow-up of 6.01 years. We found strong evidence of an association between SSRIs/SNRIs and the risk of OFs (adjusted HR = 1.32, 95% CI:1.29–1.35). Compared to periods of no exposure, SSRIs/SNRIs increased the risk of OFs during the first 30 days (IRR = 1.38, 95% CI:1.26–1.51), during the first 90 days (IRR = 1.58, 95% CI: 1.48–1.69), and the remaining exposure (IRR = 1.42, 95% CI:1.37–1.48).ConclusionsIn a population of menopausal women with CMHDs, the prescribing of SSRIs/SNRIs antidepressants was associated with a higher risk of OFs. Careful assessment of osteoporosis risk needs to be considered when treating menopausal women with SSRIs/SNRIs antidepressants.

Temperature variability and influenza incidence in China: Effect modification by ambient fine particulate matter

This study aims to examine the association between temperature variabilit (TV) exposure and influenza incidence in China, and the modification effect of PM2.5 levels. Data on daily influenza cases, weather conditions, and PM2.5 concentrations were collected from 339 cities across mainland China from 2014 to 2019. TV was computed as the standard deviation of daily maximum and minimum temperatures for the current day and the previous several days (i.e., TV0–1 to TV0–7). A space-time-stratified case-crossover design with conditional Poisson regression was employed. Overall, each 1 °C increase in TV0–6 was linked to 3.3 % (95 % CI: 3.1 %, 3.5 %) rise in influenza incidence, potentially attributing 14.73 % (95 % CI: 14.08 %, 15.37 %) of cases to this exposure. PM2.5 concentration showed substantial modification effect on the association, such that the relative risk (RR) of influenza incidence grew from 1.027 (95 % CI: 1.025, 1.029) to 1.040 (95 % CI: 1.038, 1.042) as PM2.5 levels increased from 15 to 75 μg/m³ . Females and individuals over 65 years old were more susceptible to TV exposure and the PM2.5 modification. Stronger effects were observed during cold season and in North region. The findings highlight the integrating considerations of TV and PM2.5 exposures into public health measures for influenza prevention and control.

Ocular Adverse Events Following Coronavirus Disease 2019 Infection: A Self-controlled Case Series Study from the Entire Korean Population

This study aimed to assess the risk of ocular adverse events, including retinal artery occlusion (RAO), retinal vein occlusion (RVO), noninfectious uveitis (NIU), noninfectious scleritis (NIS), optic neuritis (ON), ischemic optic neuropathy (ION), and ocular motor cranial nerve palsy (OMCNP), after coronavirus disease 2019 (COVID-19) infection. Population-based self-controlled case series (SCCS). The study included patients from the entire Korean population of 52 million who experienced incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP between January 1, 2021, and October 29,2022. This nationwide SCCS utilized data from the Korea National Health Insurance Service and the Korea Disease Control and Prevention Agency. The risk period after infection was defined as up to 24 weeks after COVID-19 infection. Conditional Poisson regression was used to calculate the relative incidence rate ratios (IRRs) for RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP during the designated risk periods. The IRRs for RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP during the risk periods. The study included 9336, 103362, 201010, 25428, 23744, 3026, 69933, and 16335 cases of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP, respectively. The IRRs (95% confidence interval) during the early risk period (1-8 weeks) were 0.94 (0.83-1.07), 1.01 (0.97-1.04), 1.00 (0.98-1.03), 0.96 (0.90-1.03), 1.00 (0.94-1.07), 0.97 (0.81-1.17), 0.97 (0.93-1.01), and 1.02 (0.94-1.11), respectively. In the late risk period (9-24 weeks), the IRRs were 1.02 (0.92-1.12), 1.01 (0.98-1.04), 1.01 (0.99-1.03), 1.02 (0.97-1.08), 1.02 (0.97-1.08), 0.99 (0.85-1.15), 1.02 (0.99-1.06), and 0.97 (0.90-1.03), respectively. Stratified analyses showed that in patients with a history of cerebro-cardiovascular disease, the risk of RAO increased during the late risk period, with an IRR (95% confidence interval) of 1.19 (1.02-1.40). The risk of incident RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP did not increase after COVID-19 infection. The risk of incident RAO increased only in individuals with preexisting cardio-cerebrovascular disease. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Concomitant Use of Oral Anticoagulants with Oral Dipeptidyl Peptidase-4 Inhibitors and Serious Bleeding Events.

In a prior screening study, saxagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4i), was found to have an increased rate of serious bleeding when used concomitantly with several oral anticoagulants (OACs). We aimed to confirm or refute the associations between concomitant use of individual OACs and DPP-4is and serious bleeding in a large US database, using self-controlled case series (SCCS) and case-crossover (CCO) designs. The study population was eligible Medicare beneficiaries co-exposed to a DPP-4i (precipitant) and either an OAC (object drug) or lisinopril (negative control object drug) in 2016-2020. For the SCCS, we used conditional Poisson regression to estimate adjusted rate ratios (RRs) between each co-exposure (vs. not) and serious bleeding and divided the RR by the adjusted RR for the corresponding lisinopril + precipitant pair to obtain ratios of RRs (RRRs). For the CCO, we estimated the adjusted odds ratios (ORs) of exposure to the precipitant in the focal window vs. referent window using multivariable conditional logistic regression and divided the ORs in the object drug-exposed cases over the ORs in negative object drug-exposed cases to obtain the ratios of ORs (RORs). The adjusted RRRs for serious bleeding ranged from 0.32 (0.05-1.91) for apixaban/lisinopril + saxagliptin to 3.49 (1.29-9.48) for warfarin/lisinopril + linagliptin. The adjusted RORs ranged from 0.01 (0.00-0.20) for rivaroxaban/lisinopril + saxagliptin to 2.99 (0.74-12.11) for apixaban/lisinopril + linagliptin. While we could not confirm previously identified signals because of statistical imprecision, several numerically elevated estimates still warrant caution in concomitant use and further examination.

Ocular Adverse Events After Influenza Vaccination in Older Adults: Self-Controlled Case Series Using a Large Database in Japan

ABSTRACT Background To clarify the risk of adverse ocular events following influenza vaccination. Methods This self-controlled case series study used a claims database linked to vaccination records of a large city in Japan between April 2014 and September 2021. Individuals aged ≥ 65 years who developed adverse ocular events during the follow-up period were included. The exposure was influenza vaccination. The primary outcome was defined as the occurrence of at least one of the following five eye diseases: uveitis, scleritis, retinal vein occlusion, retinal artery occlusion, or optic neuritis. Conditional Poisson regression was used to estimate the within-subject incidence rate ratio of ocular adverse events during the risk period (0–56 days after vaccination) compared to the control period. Results A total of 4,527 cases were eligible for the study (median age, 74 years; male, 42%). The incidence rate ratio for the outcome during the risk period was 0.99 (95% confidence interval, 0.87 to 1.14). No increased risk was observed for individual components of the outcome either; the incidence rate ratio was 0.94 (0.78 to 1.13) for uveitis, 1.17 (0.86 to 1.59) for scleritis, 0.98 (0.76 to 1.27) for retinal vein occlusion, 0.89 (0.42 to 1.87) for retinal artery occlusion, and 0.87 (0.44 to 1.70) for optic neuritis. Conclusions This self-controlled case series showed no apparent increase in the risk of adverse ocular events after influenza vaccination among older adults. These results mitigate the concerns of older adults who may hesitate to receive influenza vaccination for fear of adverse ocular events. Abbreviation HR = hazard ratio; CI = confidence interval; RVO = retinal vein occlusion; SCCS = self-controlled case series

Cholinesterase Inhibitor Initiation Does Not Increase the Risk of Fall-Related Injury in Older Adults Treated With Beta-Blockers: A Self-Controlled Case Series Design.

Prescribing cholinesterase inhibitors (ChEIs) concurrently with beta-blockers might cause syncope that increases the risk of fall-related injuries (FRIs). This self-controlled case series study assesses the risk of FRIs associated with initiating ChEIs while receiving beta-blockers among Medicare fee-for-service-insured nursing home (NH) residents in the United States. We identified individuals at their first dispensing of a beta-blocker between 2016 and 2019 after at least 45 days of long-stay NH residency. Individuals were followed from the first day of beta-blocker use until beta-blocker discontinuation, Medicare disenrollment, death, or study end. ChEI initiation was classified as the first 60 days of new ChEI dispensing after 45 days of no ChEI exposure. FRIs were assessed during beta-blocker use periods, and age-adjusted incidence rate ratios (IRR) for ChEI-initiation days versus other days were calculated using conditional Poisson regression models. Analyses were weighted for event-dependent observation periods due to the high risk of mortality after an FRI in this population. Subgroup analyses were conducted for several key time-fixed variables, including sex, age, ChEI type, ChEI dose, beta-blocker selectivity, and beta-blocker dose. The FRI risk after ChEI initiation was not elevated among 837 residents who experienced an FRI while using beta-blockers (IRR=0.90 [95%CLs 0.71, 1.15]). Analyses of ChEI initiation in several subgroups yielded similar results. There was no substantial difference in FRI risk when initiating ChEIs among older NH residents receiving beta-blocker therapy versus periods without ChEI initiation, suggesting that there is no clinically significant pharmacodynamic drug-drug interaction between beta-blockers and ChEIs.

Effects of combined exposure to fine particulate matter and cold waves and on IHD hospitalizations at low and high altitudes

Climate change and air pollution are major challenges facing the world today. Cold waves and air pollution significantly impact ischemic heart disease (IHD), but the extent of these effects at different altitudes remains unclear, especially their interactions. We collected daily meteorological, pollutant, and IHD hospitalization data from Xining and Xinxiang from 2016 to 2021. Using a time-stratified case-crossover approach, we fitted conditional Poisson regression models to assess the association between cold waves, PM2.5, and IHD hospitalizations and quantified their interactions. Additionally, we calculated the attributable fraction (AF) and attributable number (AN) of hospitalizations due to exposure to cold waves and medium to high-level PM2.5. We also performed stratified analyses by altitude, gender, and age. Both cold waves and PM2.5 were positively associated with IHD hospitalization rates in Xining and Xinxiang, but the differences between the two regions were not significant. The relative risk of cold waves was 1.15 (1.07, 1.24) in Xining and 1.16 (1.11, 1.21) in Xinxiang. In Xining, there was an interaction between cold waves and different levels of PM2.5. We estimated the attributable fraction due to the joint exposure of cold waves and PM2.5 to be 0.14–0.49 in Xining and 0.26–0.36 in Xinxiang. Older adults and males faced higher risks. This study highlights the importance of reducing PM2.5 exposure and optimizing extreme weather warning systems and suggests further exploration of the impacts of individual behaviors and regional characteristics on IHD.

A case-crossover analysis to quantify the impact of wildfire smoke on hospital respiratory admissions in the Rogue Valley, Oregon

BackgroundWith the increasing prevalence of wildfire smoke in the Pacific Northwest, it is important to quantify health impacts to plan for adequate health services. The Rogue Valley region has historically faced some of the greatest wildfire threats in the state. Health impacts from smoke have been estimated in several recent studies that include Oregon's Rogue Valley, but the results between studies are conflicting. ObjectiveThe objective is to critically examine impacts of wildfire smoke on health in the Rogue Valley area and translate the results to support hospital staffing decisions. Study designThe study adopts a case-crossover approach. MethodsApply a conditional Poisson regression to analyze time stratified counts while controlling for mean temperature. ResultsEvery 10 μ/m3 increase in PM2.5 is associated with a 2% increase in same-day hospital or emergency room admission rates for respiratory conditions during fire season after adjusting for temperature and time (OR = 1.020; 95% CI: 1.004–1.034); a 10 μ/m3 increase in PM2.5 lasting nine days is associated with a 4% increase in admission rates (OR = 1.041; 95% CI: 1.018–1.065). In other words, for each 10 μ/m3 single day increase in pollution from smoke, an additional 0.26 respiratory patients would be expected in the area hospitals. With a single day increase from 10 μ/m3 to 150 μ/m3, hospitals could expect an additional four patients. ConclusionsThere are small but significant health impacts in the Rogue Valley. These impacts are smaller than some statewide estimates. We need further research to understand these differences.

COVID-19 Vaccination and Ocular Adverse Events: A Self-Controlled Case Series Study From the Entire South Korean Population

This study aimed to assess the risk of ocular adverse events, including retinal artery occlusion (RAO), retinal vein occlusion (RVO), noninfectious uveitis (NIU), noninfectious scleritis (NIS), optic neuritis (ON), ischemic optic neuropathy (ION), and ocular motor cranial nerve palsy (OMCNP), following Coronavirus Disease 2019 (COVID-19) vaccination. Population-based self-controlled case series METHODS: This study utilized nationwide claims and vaccination data provided by the Korea National Health Insurance Service and Korea Disease Control and Prevention Agency. From the entire South Korean population of 52 million individuals, patients with incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP between January 2021 and March 2022 were included. The postvaccination risk period was defined as up to 56 days after COVID-19 vaccination. The relative incidence rate ratios (IRRs) for RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP during the risk periods were measured using conditional Poisson regression. The study included 6,590, 70,120, 137,958, 17,921, 15,492, 2,039, 49,089, and 11,312 cases of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP, respectively. The IRRs (95% confidence interval) during the early risk period (0-28 days) were 0.95 (0.88-1.01), 0.96 (0.94-0.98), 0.93 (0.91-0.94), 0.93 (0.89-0.96), 0.96 (0.92-1.01), 1.04 (0.92-1.18), 0.98 (0.95-1.00), and 0.91 (0.86-0.96), respectively. In the late risk period (29-56 days), the IRRs were 0.96 (0.89-1.03), 0.93 (0.91-0.96), 0.96 (0.95-0.98), 1.00 (0.95-1.04), 0.96 (0.91-1.01), 1.00 (0.87-1.15), 1.01 (0.98-1.04), and 0.95 (0.90-1.01), respectively. COVID-19 vaccination did not increase the risk of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP during the postvaccination period.

Prevalent and new use of common drugs for the incidence of community-acquired acute kidney injury: cohort and case-crossover study

Although community-acquired acute kidney injury (CA-AKI) represents a significant subset of all AKI incidence, evidence is limited due to the lack of comprehensive data prior to diagnosis. Here, we examined the risk of drug use for CA-AKI by using exhaustive pre-diagnostic prescription data. We included 78,754 working-age healthy individuals who underwent an annual health checkup program. We conducted a cohort study to assess the association between prevalent drug use and subsequent CA-AKI incidence using the Cox proportional hazard model. Subsequently, we conducted a case-crossover study to compare the new drug use in the case period directly before the CA-AKI incidence (− 3 to 0 months) with that in the control period far before the CA-AKI incidence (− 15 to − 12 months and − 9 to − 6 months) using the conditional Poisson regression model. The prevalent use of renin–angiotensin–aldosterone system (RAAS) inhibitors was associated with an increased CA-AKI incidence, but the new use was not. The new use of diuretics, anti-infectious drugs, and contrast medium was also associated with an increased CA-AKI incidence. These results suggest we need to pay attention for the incidence of AKI among the general population taking those common drugs.

Association between precipitation and mortality due to diarrheal diseases by climate zone: A multi-country modeling study.

Precipitation could affect the transmission of diarrheal diseases. The diverse precipitation patterns across different climates might influence the degree of diarrheal risk from precipitation. This study determined the associations between precipitation and diarrheal mortality in tropical, temperate, and arid climate regions. Daily counts of diarrheal mortality and 28-day cumulative precipitation from 1997 to 2019 were analyzed across 29 locations in eight middle-income countries (Argentina, Brazil, Costa Rica, India, Peru, the Philippines, South Africa, and Thailand). A two-stage approach was employed: the first stage is conditional Poisson regression models for each location, and the second stage is meta-analysis for pooling location-specific coefficients by climate zone. In tropical climates, higher precipitation increases the risk of diarrheal mortality. Under extremely wet conditions (95th percentile of 28-day cumulative precipitation), diarrheal mortality increased by 17.8% (95% confidence interval [CI] = 10.4%, 25.7%) compared with minimum-risk precipitation. For temperate and arid climates, diarrheal mortality increases in both dry and wet conditions. In extremely dry conditions (fifth percentile of 28-day cumulative precipitation), diarrheal mortality risk increases by 3.8% (95% CI = 1.2%, 6.5%) for temperate and 5.5% (95% CI = 1.0%, 10.2%) for arid climates. Similarly, under extremely wet conditions, diarrheal mortality risk increases by 2.5% (95% CI = -0.1%, 5.1%) for temperate and 4.1% (95% CI = 1.1%, 7.3%) for arid climates. Associations between precipitation and diarrheal mortality exhibit variations across different climate zones. It is crucial to consider climate-specific variations when generating global projections of future precipitation-related diarrheal mortality.

Heat-related illness among workers in British Columbia, Canada: Extreme hot weather in 2021 compared to 2001-2020.

British Columbia (BC), Canada, experienced an unprecedented summer with record-breaking high temperatures in 2021. Yet the health impact has not been examined in occupational settings. This study aimed to characterize occupational heat-related illness (HRI) among BC workers estimated by incidence rates and associations between heatwaves and HRI, compare risks from 2021 and prior summers of 2001-2020, and assess differential impacts on worker groups by demographics and occupations. We identified HRI from workers' compensation claims that occurred between June and August from 2001-2021 in BC. Incidence rates were calculated using working population estimates from Statistics Canada's Labour Force Survey. A time-stratified case-crossover design with conditional Poisson regression was used to examine the impact of heatwaves on occupational HRI. All analyses were stratified by year (2021 versus 2001-2020), age, sex, and occupation. Of the 521 claims identified, 107 (21%) occurred in 2021. Incidence rates for 2021 and prior summers were 3.97 [95% confidence interval (CI) 3.26-4.80] and 0.93 (95% CI 0.85-1.03) claims per 100 000 workers, respectively. This difference represents a 327% increase. Rates were higher in health occupations in 2021 versus 2001-2020. During 2001-2021, the risk of HRI during heatwave days was 4.33 (95% CI 2.98-6.27) times that during non-heatwave days, and the risk was higher among middle-aged workers and workers in trades, transport, and equipment operations. The 2021 heatwaves had greater impact on younger and female workers than those from prior summers. Heat is a crucial workplace hazard. Prevention strategies should prioritize at-risk workers and not be limited to heatwaves.

Risk of incident gout following exposure to recombinant zoster vaccine in US adults aged ≥65 years

ObjectiveAssess the risk of incident gout following exposure to recombinant zoster vaccine (RZV). MethodsThis case-only, self-controlled risk interval study included a cohort of US fee-for-service Medicare (Part A, B, and D) beneficiaries aged ≥65 years. The exposure was receipt of at least one dose of the two-dose RZV regimen in 2018 or 2019. The risk and control windows were days 1–30 and days 31–60, respectively, following vaccination. Incident gout was defined as the first episode of gout during the risk or control window, with no evidence of gout in the last 365 days. We estimated the relative risk (RR) and 95 % confidence interval (CI) of incident gout in the risk window relative to the control window, using conditional Poisson regression models. Sensitivity analyses included a dose-compliant subanalysis of individuals who received dose 2 60–183 days after dose 1; dose-specific analysis; seasonality adjustment; and COVID-19 adjustment for potential detection bias due to the pandemic. ResultsThe 1290 RZV-exposed individuals with incident gout were primarily White (86.98 %), male (61.16 %), and aged 70–79 years (55.82 %). The RR of incident gout was 1.00 (95 % CI 0.90, 1.12). In the dose-compliant sensitivity analysis (n = 959 cases of incident gout), the RR of incident gout was 0.99 (95 % CI 0.87, 1.13). The findings were unchanged in the dose-specific, seasonality, and COVID-19 sensitivity analyses. ConclusionThe findings suggest that RZV is not significantly associated with an increased risk of incident gout in the Medicare population aged ≥65 years.

Assessing long-term effects of gaseous air pollution exposure on mortality in the United States using a variant of difference-in-differences analysis

Long-term mortality effects of particulate air pollution have been investigated in a causal analytic frame, while causal evidence for associations with gaseous air pollutants remains extensively lacking, especially for carbon monoxide (CO) and sulfur dioxide (SO2). In this study, we estimated the causal relationship of long-term exposure to nitrogen dioxide (NO2), CO, SO2, and ozone (O3) with mortality. Utilizing the data from National Morbidity, Mortality, and Air Pollution Study, we applied a variant of difference-in-differences (DID) method with conditional Poisson regression and generalized weighted quantile sum regression (gWQS) to investigate the independent and joint effects. Independent exposures to NO2, CO, and SO2 were causally associated with increased risks of total, nonaccidental, and cardiovascular mortality, while no evident associations with O3 were identified in the entire population. In gWQS analyses, an interquartile range-equivalent increase in mixture exposure was associated with a relative risk of 1.067 (95% confidence interval: 1.010–1.126) for total mortality, 1.067 (1.009–1.128) for nonaccidental mortality, and 1.125 (1.060–1.193) for cardiovascular mortality, where NO2 was identified as the most significant contributor to the overall effect. This nationwide DID analysis provided causal evidence for independent and combined effects of NO2, CO, SO2, and O3 on increased mortality risks among the US general population.

Effect of non-optimal ambient temperature on preterm birth stratified by social positioning in Nepal: A space–time-stratified case-crossover study

BackgroundThe ongoing increase in the mean global temperature due to human induced climate change, indicates that women and infants will have higher exposure to heat events leading to adverse outcomes. The study investigates the effect of non-optimal ambient temperature on the risk of preterm birth stratified by social position in Nepal. MethodThis is a space–time-stratified case-crossover design, based on hospital-registered perinatal data between 2017 and 2021 (n = 47,807). A daily count of pregnant women residing in seven heat-prone districts was extracted together with their social status (ethnicity), obstetric complication and gestation of birth. The daily count of events was matched with the daily ambient temperature of their residence using the NOAA spatial temperature recording. Ambient temperature exposure was analysed using conditional Poisson regression and distributed lag non-linear models. FindingsIn the general population, with exposure to ambient temperature at the 75th centile (28 °C) the cumulative risk of preterm birth over 28 days was 1·29 times higher (RR, 1·29; 95% CI; 1·09, 1·54) than at median temperature (24.1 °C), and even higher among the socially disadvantaged population. Cumulative risk of preterm birth to cold ambient temperature at the 1st centile was high but not significant. Exposure to ambient temperature at the 90th centile (32·5 °C) had the highest cumulative risk of preterm birth for pregnant women from socially disadvantaged populations (RR 1·81; 95% CI; 1·28, 2·55). The delayed effect after exposure to temperatures above the 75th percentile was more prolonged in the disadvantaged than the advantaged social group. ConclusionAlthough exposure to cold with certain effect on preterm births, heat (increase in ambient temperature) carries a risk of preterm birth in Nepal, and is more profound among socially disadvantaged populations.