Air pollution and stroke. A new modifiable risk factor is in the air

Endovascular treatment for basilar artery occlusion: a cost-effectiveness analysis based on a meta-analysis

Objective

This study aimed to investigate the efficacy and economic effect of endovascular treatment (EVT) combined with standard medical treatment (SMT) vs. SMT alone in Chinese patients with basilar artery occlusion (BAO) from the perspective of the Chinese healthcare system.

Methods

We conducted a cost-effectiveness analysis using the results from a meta-analysis comparing EVT and SMT efficacy in Chinese patients with BAO-induced stroke using direct medical costs from the China National Stroke Registry. The meta-analysis's primary outcome was excellent functional outcome (mRS scores of 0-2), with secondary outcomes being poor functional outcome (mRS scores of 3-5) and death (mRS score of 6). To compare EVT plus SMT's cost-effectiveness with that of SMT alone, we constructed a combined decision tree and Markov model with a lifetime duration and a 3-month cycle length. The primary cost-effectiveness outcome was the incremental cost-effectiveness ratio (ICER), representing the incremental cost per incremental quality-adjusted life year (QALY). EVT was considered cost-effective if the ICER was lower than the willingness-to-pay (WTP) threshold of three times the per capita gross domestic product (GDP) in 2021 in China; otherwise, it would not be cost-effective.

Results

The meta-analysis results indicated that EVT could increase the incidence of excellent functional outcomes, with a risk ratio (RR) of 2.23 (95% confidence interval, CI, 1.18-4.21), p = 0.01. Simultaneously, EVT reduced the risk of poor functional outcome and mortality in the EVT group, with RRs of 0.83 (95% CI, 0.67-1.03), p = 0.09, and 0.71 (95% CI, 0.59-0.85), p = 0.0002, respectively. The study also found that EVT plus SMT resulted in a lifetime effectiveness of 2.15 QALY (3.88 life years) for 32,213 international dollars (Intl.$) per patient with BAO. In contrast, SMT alone achieved an effectiveness of 1.46 QALY (3.03 life years) with a total cost of Intl.$ 13,592 per patient. The ICER was Intl.$ 27,265 per QALY (Intl.$ 22,098 per life-year), which fell below the WTP threshold.

Conclusion

Compared to SMT, EVT improves the prognosis of BAO-induced stroke. Considering the Chinese healthcare system, adding EVT to SMT proves to be cost-effective for patients with BAO compared to SMT alone.

Dynamic association of ambient air pollution with incidence and mortality of pulmonary hypertension: A multistate trajectory analysis

BACKGROUND

There is little evidence regarding the association between ambient air pollution and incidence and the mortality of pulmonary hypertension (PH).

METHODS

We included 494,750 participants at baseline in the UK Biobank study. Exposures to PM2.5, PM10, NO2, and NOx were estimated at geocoded participants' residential addresses, utilizing pollution data provided by UK Department for Environment, Food and Rural Affairs (DEFRA). The outcomes were the incidence and mortality of PH. We used multivariate multistate models to investigate the impacts of various ambient air pollutants on both incidence and mortality of PH.

RESULTS

During a median follow-up of 11.75 years, 2517 participants developed incident PH, and 696 died. We observed that all ambient air pollutants were associated with increased incidence of PH with different magnitudes, with adjusted hazard ratios (HRs) [95% confidence intervals (95% CIs)] for each interquartile range (IQR) increase of 1.73 (1.65, 1.81) for PM2.5, 1.70 (1.63, 1.78) for PM10, 1.42 (1.37, 1.48) for NO2, and 1.35 (1.31, 1.40) for NOx. Furthermore, PM2.5, PM10, NO2 and NO2 influenced the transition from PH to death, and the corresponding HRs (95% CIs) were 1.35 (1.25, 1.45), 1.31 (1.21, 1.41), 1.28 (1.20, 1.37) and 1.24 (1.17, 1.32), respectively.

CONCLUSION

The results of our study indicate that exposure to various ambient air pollutants might play key but differential roles in both the incidence and mortality of PH.

Clustering of Environmental Parameters and the Risk of Acute Ischaemic Stroke

Acute ischaemic stroke (AIS) risk on days with similar environmental profiles remains unknown. We investigated the association between clusters of days with similar environmental parameters and AIS incidence in Singapore. We grouped calendar days from 2010 to 2015 with similar rainfall, temperature, wind speed, and Pollutant Standards Index (PSI) using k-means clustering. Three distinct clusters were formed 'Cluster 1' containing high wind speed, 'Cluster 2' having high rainfall, and 'Cluster 3' having high temperatures and PSI. We aggregated the number of AIS episodes over the same period with the clusters and analysed their association using a conditional Poisson regression in a time-stratified case-crossover design. Comparing the three clusters, Cluster 3 had the highest AIS occurrence (IRR 1.09; 95% confidence interval (CI) 1.05-1.13), with no significant difference between Clusters 1 and 2. Subgroup analyses in Cluster 3 showed that AIS risk was amplified in the elderly (≥65 years old), non-smokers, and those without a history of ischaemic heart disease/atrial fibrillation/vascular heart disease/peripheral vascular disease. In conclusion, we found that AIS incidence may be higher on days with higher temperatures and PSI. These findings have important public health implications for AIS prevention and health services delivery during at-risk days, such as during the seasonal transboundary haze.

High-risk population and factors of stroke has changed among middle-aged and elderly Chinese-Evidence from 1989 to 2015

Background

Stroke is an acute cerebrovascular disease with high mortality and disability. This study aimed to investigate the trend of stroke prevalence from 1989 to 2015 in China, explore the transition of high-risk population and high-risk factors, and provide some evidence to develop more targeted stroke intervention strategies.

Material and methods

We derived the baseline data from China Health and Nutrition Survey (CHNS). Participants responded to face-to-face interviews and examinations containing demographic information, behavioral health information, disease history, and physical examination. We applied chi-square test, shapley value decomposition model, and decision tree model to evaluate the changes of high-risk population and high-risk factors of stroke.

Results

Across 42,419 middle-aged and elderly residents, the prevalence of stroke was decreasing from 1989 to 2015. Hypertension was the leading risk factor of stroke, while its contribution rate was weakened with the increasing of medicine taking rate. As the second risk factor of stroke, the contribution of age decreased either. Meanwhile, the contribution rate of historical health factors, lifestyle factors, and regional factors, such as body mass index, diabetes, and living area to the impact of stroke was increasing. In addition, the first high-risk population of stroke changed from hypertension patients aged 75 years and above to without spouse residents living in stroke belt such as Beijing and Liaoning. The second risk population of stroke transformed from male hypertensive patients under 75 years old into male hypertensive patients living in urban. The third high-risk group turned from the elderly aged 75 and above into the female patients with hypertension and diabetes.

Conclusions

This study demonstrated that the high-risk population and high-risk factors of stroke changed in China and revealed the direction and internal mechanism of transition of stroke. Targeted stroke intervention strategies should be renewed. Health education for the high-risk population of stroke should be carried out, healthy living habits need be advocated, and the use of antihypertensive drugs for the hypertensive patients should be standardized.

Air Pollution and Its Devastating Effects on the Central Nervous System

Air pollution is a real public health problem, it being one of the five most common causes of mortality in developing countries. However, pollution studies have focused on the cardiovascular and pulmonary systems in recent decades. Recently, researchers have moved towards a new direction, tracing a direct link between pollution and stroke. Stroke has many known risk factors such as smoking, a sedentary lifestyle, and hypertension. Pollution is universally widespread, already a matter of public interest, so that, although intuitive, it is difficult to connect the two. The particles found in the air that we breathe, regardless of their origin, can attack the body in different ways, causing inflammation, and triggering a true cascade of phenomena that end up attacking the central nervous system and other organs. This article tries to explain the series of phenomena that determine the harmful effect of particles present in the air, with an increased focus on the central nervous system and especially on strokes. A deeper understanding of these phenomena helps in guiding future studies and finding viable solutions to protect people at risk.

Accurate Prediction of Stroke for Hypertensive Patients Based on Medical Big Data and Machine Learning Algorithms: Retrospective Study

Background

Stroke risk assessment is an important means of primary prevention, but the applicability of existing stroke risk assessment scales in the Chinese population has always been controversial. A prospective study is a common method of medical research, but it is time-consuming and labor-intensive. Medical big data has been demonstrated to promote disease risk factor discovery and prognosis, attracting broad research interest.

Objective

We aimed to establish a high-precision stroke risk prediction model for hypertensive patients based on historical electronic medical record data and machine learning algorithms.

Methods

Based on the Shenzhen Health Information Big Data Platform, a total of 57,671 patients were screened from 250,788 registered patients with hypertension, of whom 9421 had stroke onset during the 3-year follow-up. In addition to baseline characteristics and historical symptoms, we constructed some trend characteristics from multitemporal medical records. Stratified sampling according to gender ratio and age stratification was implemented to balance the positive and negative cases, and the final 19,953 samples were randomly divided into a training set and test set according to a ratio of 7:3. We used 4 machine learning algorithms for modeling, and the risk prediction performance was compared with the traditional risk scales. We also analyzed the nonlinear effect of continuous characteristics on stroke onset.

Results

The tree-based integration algorithm extreme gradient boosting achieved the optimal performance with an area under the receiver operating characteristic curve of 0.9220, surpassing the other 3 traditional machine learning algorithms. Compared with 2 traditional risk scales, the Framingham stroke risk profiles and the Chinese Multiprovincial Cohort Study, our proposed model achieved better performance on the independent validation set, and the area under the receiver operating characteristic value increased by 0.17. Further nonlinear effect analysis revealed the importance of multitemporal trend characteristics in stroke risk prediction, which will benefit the standardized management of hypertensive patients.

Conclusions

A high-precision 3-year stroke risk prediction model for hypertensive patients was established, and the model's performance was verified by comparing it with the traditional risk scales. Multitemporal trend characteristics played an important role in stroke onset, and thus the model could be deployed to electronic health record systems to assist in more pervasive, preemptive stroke risk screening, enabling higher efficiency of early disease prevention and intervention.

Air Pollution: A Neglected Risk Factor for Dementia in Latin America and the Caribbean

The risk of dementia and Alzheimer's disease in Latin America and the Caribbean (LAC) rises with increasing age and polluted air. Currently, at least 172 million people breathe unhealthy levels of air pollution in LAC countries. Several cohort studies have indicated that air pollution increases the risk of developing dementia and neurodegenerative diseases, but the mechanisms underlying the association are still not clear. Air pollution causes and aggravates five established risk factors for dementia (obesity, hypertension, stroke, diabetes mellitus, and heart diseases) and is linked to three other risk factors (physical inactivity, cognitive inactivity, and depression). Some of these risk factors could be mediating the association between air pollution and dementia. Reducing the risks for dementia is crucial and urgently needed in LAC countries. There is room for improving air quality in many urban areas in the LAC region and other low- and middle-income countries (LMICs), a routealready explored by many urban areas in developing regions. Moreover, reducing air pollution has proved to improve health outcomes before. In this article, we propose that despite the ongoing and valid scientific discussion, if air pollution can or cannot directly affect the brain and cause or aggravate dementia, we are ready to consider air pollution as a potentially modifiable risk factor for dementia in LAC and possibly in other LMICs. We suggest that controlling and reducing current air pollution levels in LAC and other LMIC regions now could strongly contribute.

Insomnia associated with traffic noise and proximity to traffic-a cross-sectional study of the Respiratory Health in Northern Europe III population

STUDY OBJECTIVES

Exposure to traffic noise increases the risk of sleeping disturbance, but little is known about the effect of traffic-related air pollution on insomnia symptoms. We aimed to investigate the separate associations of self-reported proximity to traffic and traffic noise with insomnia.

METHODS

This is a cross-sectional study of the population included in the Respiratory Health in Northern Europe study, consisting of randomly selected men and women born between 1945 and 1973, from 7 Northern European centers. Hearing traffic noise in the bedroom, bedroom window proximity to traffic, and insomnia symptoms were self-reported. Bedroom window proximity to traffic was used as a surrogate for exposure to traffic-related air pollution. The following insomnia symptoms were assessed: difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening.

RESULTS

A total of 12,963 individuals was included. Traffic noise was positively associated with all three insomnia symptoms: difficulty initiating sleep (odds ratio [OR] = 3.54; 95% confidence interval [CI]: 1.85, 6.76), difficulty maintaining sleep (OR = 2.95; 95% CI: 1.62, 5.37), and early morning awakening (OR = 3.25; 95% CI: 1.97, 5.37). Proximity to traffic without disturbing noise was associated with difficulty initiating sleep (OR = 1.62; 95% CI: 1.45, 1.82).

CONCLUSIONS

This study adds further support to the identification of traffic noise as a risk factor for insomnia. Proximity to traffic without being exposed to noise was associated with an increased risk of difficulty initiating sleep. Our findings indicate that insomnia may be associated with both traffic noise and traffic-related air pollution.

Seasonal patterns and associations in the incidence of acute ischemic stroke requiring mechanical thrombectomy

Background

In order to identify risk periods with an increased demand in technical and human resources, we tried to determine patterns and associations in the incidence of acute ischemic stroke due to embolic large vessel occlusions (eLVO) requiring mechanical thrombectomy (MT).

Methods

We conducted a time series analysis over a 9‐year period (2010–2018) based on observational data in order to detect seasonal patterns in the incidence of MT due to eLVO (n = 2628 patients). In a series of sequential negative binominal regression models, we aimed to detect further associations (e.g., temperature, atmospheric pressure, air pollution).

Results

There was a 6‐month seasonal pattern in the incidence of MT due to eLVO (p = 0.024) peaking in March and September. Colder overall temperature was associated with an increase in MT due to eLVO (average marginal effect [AME], [95% CI]: −0.15 [−0.30–0.0001]; p = 0.05; per °C). A current increase in the average monthly temperature was associated with a higher incidence of MT due to eLVO (0.34 [0.11–0.56]; p = 0.003). Atmospheric pressure was positively correlated with MT due to eLVO (0.38 [0.13–0.64]; p = 0.003; per hectopascal [hPa]). We could detect no causal correlation between air pollutants and MT due to eLVO.

Conclusions

Our data suggest a 6‐month seasonal pattern in the incidence of MT due to eLVO peaking in spring and early autumn. This might be attributed to two different factors: (1) a current temperature rise (comparing the average monthly temperature in consecutive months) and (2) colder overall temperature. These results could help to identify risk periods requiring an adaptation in local infrastructure.

Impact of the COVID-19 pandemic and a national lockdown on hospitalizations for stroke and related 30-day mortality in France: A nationwide observational study

BACKGROUND AND PURPOSE

The aim of this nationwide study was to assess the impact of the COVID-19 pandemic on stroke hospitalization rates, patient characteristics and 30-day case fatality rates.

METHODS

All hospitalizations for stroke from January to June of each year from 2017 to 2020 were selected using International Classification of Diseases, 10th revision, codes I60 to I64 in the national hospital discharge database. Patient characteristics and management were described according to three time periods: pre-lockdown, lockdown, and post-lockdown. Weekly incidence rate ratios (IRRs) were computed to compare time trends in the rates of patients hospitalized for stroke as well as in-hospital and 30-day case fatality rates between the years 2017-2019 and 2020.

RESULTS

In 2020, between weeks 1 and 24, 55,308 patients were hospitalized for stroke in France. IRRs decreased by up to 30% for all age groups, sex, and stroke types during the lockdown compared to the period 2017-2019. Patients hospitalized during the second and third weeks of the lockdown had higher in-hospital case fatality rates compared to 2017-2019. In-hospital case fatality rates increased by almost 60% in patients aged under 65 years. Out-of-hospital 30-day case fatality rates increased between weeks 11 and 15 among patients who returned home after their hospitalization. Important changes in care management were found, including fewer stroke patients admitted to resuscitation units, more admitted to stroke care units, and a shorter mean length of hospitalization.

CONCLUSIONS

During the first weeks of the lockdown, rates of patients hospitalized for stroke fell by 30% and there were substantial increases of both in-hospital and out-of-hospital 30-day case fatality rates.

Hypertension and stroke in Asia: A comprehensive review from HOPE Asia

Stroke is the primary cause of disability and vascular death worldwide, including Asia. Asian characteristics that differ from the West lead to higher stroke incidence. Stroke epidemiology studies in Asia have shown varying levels of mortality, incidence, prevalence, and burden of disease. Hypertension is the most prevalent risk factor found in Asia. Besides ethnicity that is associated with stroke incidence, both systolic blood pressure, diastolic blood pressure, and blood pressure variability are positively correlated with stroke incidence. Post-stroke cognitive impairment is one of the sequelae that affect one-third of stroke survivors and has become a significant public health concern that is often neglected despite its increasing prevalence. Therefore, it is very important to prevent recurrence by treating stroke optimally and effectively. Increasing awareness and treatment adherence to hypertension, the leading risk factor for stroke, became the main goal in several countries in Asia.

The Association of White Blood Cells and Air Pollutants-A Population-Based Study

The links of air pollutants to health hazards have been revealed in literature and inflammation responses might play key roles in the processes of diseases. WBC count is one of the indexes of inflammation, however the l iterature reveals inconsistent opinions on the relationship between WBC counts and exposure to air pollutants. The goal of this population-based observational study was to examine the associations between multiple air pollutants and WBC counts. This study recruited community subjects from Kaohsiung city. WBC count, demographic and health hazard habit data were collected. Meanwhile, air pollutants data (SO₂, NO₂, CO, PM₁₀, and O₃) were also obtained. Both datasets were merged for statistical analysis. Single- and multiple-pollutants models were adopted for the analysis. A total of 10,140 adults (43.2% males; age range, 33~86 years old) were recruited. Effects of short-term ambient concentrations (within one week) of CO could increase counts of WBC, neutrophils, monocytes, and lymphocytes. However, SO₂ could decrease counts of WBC, neutrophils, and monocytes. Gender, BMI, and smoking could also contribute to WBC count increases, though their effects are minor when compared to CO. Air pollutants, particularly SO₂, NO₂ and CO, may thus be related to alterations of WBC counts, and this would imply air pollution has an impact on human systematic inflammation.

What are the implications of climate change for speech and language therapists?

BACKGROUND

The emerging global issue of climate change has large-scale effects on health and well-being, including communication disorders. The broad range of the speech and language therapy profession's scope of practice incorporates prevention, advocacy and equality in service delivery. These act as a springboard for involvement in climate change and health.

AIMS

This is an appeal to speech and language therapists (SLTs) to focus and take action on this issue and its considerable effects on communication and swallowing disorders.

METHODS & PROCEDURES

This article discusses the importance of taking a public health position on prevention and equality of services to manage environmental determinants of communication and swallowing disorders. It also describes the extent to which climate change affects these disorders and exacerbates the inequality of healthcare services in low- and middle-income countries.

MAIN CONTRIBUTION

Five strategies are provided for action on fulfilling therapists' roles in reducing the incidence, development and exacerbation of climate-related communication and swallowing disorders, as well as the role of SLTs in acting as advocates. The case is made for expanding the scope of services to focus on prevention and service equality so as to best meet the needs of the wider community.

CONCLUSIONS & IMPLICATIONS

Despite other challenges currently facing SLTs, climate change and its increasing effects on communication disorders and dysphagia is difficult to ignore. SLTs owe it to their clients, the wider community, low- and middle-income countries, the economy, and the future to take action. What this paper adds What is already known on the subject Multiple studies published in peer-reviewed scientific journals show that climate change is extremely likely to be due to human activities. The global effects will be higher temperatures, changes in precipitation, more droughts and heatwaves, stronger and more intense hurricanes, and a rising sea level which directly threaten the health of entire populations. Other health professions are beginning to take climate change into account in training and practice. What this paper adds to existing knowledge Many disorders of communication and swallowing are caused or exacerbated by the effects of climate change. Increasing temperatures, extremes of precipitation, population displacement and air pollution contribute to cardiovascular and cerebrovascular events, respiratory disease, malnutrition, premature birth, air- and water-borne diseases, and mental illness. These may affect the communication and swallowing abilities across the lifespan, but particularly those of children and older adults. What are the potential or actual clinical implications of this work? SLTs' roles in prevention, advocacy and education act as a starting point for involvement in climate change and health. Three practical strategies for action include educating SLTs and other health professionals on climate change and its effects on communication and swallowing, promoting awareness with clients and their families, and gathering and disseminating reliable data.

Assessing environmental epidemiology questions in practice with a causal inference pipeline: An investigation of the air pollution-multiple sclerosis relapses relationship

When addressing environmental health-related questions, most often, only observational data are collected for ethical or practical reasons. However, the lack of randomized exposure often prevents the comparison of similar groups of exposed and unexposed units. This design barrier leads the environmental epidemiology field to mainly estimate associations between environmental exposures and health outcomes. A recently developed causal inference pipeline was developed to guide researchers interested in estimating the effects of plausible hypothetical interventions for policy recommendations. This article illustrates how this multistaged pipeline can help environmental epidemiologists reconstruct and analyze hypothetical randomized experiments by investigating whether an air pollution reduction intervention decreases the risk of multiple sclerosis relapses in Alsace region, France. The epidemiology literature reports conflicted findings on the relationship between air pollution and multiple sclerosis. Some studies found significant associations, whereas others did not. Two case-crossover studies reported significant associations between the risk of multiple sclerosis relapses and the exposure to air pollutants in the Alsace region. We use the same study population as these epidemiological studies to illustrate how appealing this causal inference approach is to estimate the effects of hypothetical, but plausible, environmental interventions.