The effect of season and temperature variation on hospital admissions for incident stroke events in Maputo, Mozambique

Forecasting extremely high ischemic stroke incidence using meteorological time serie

MOTIVATION

The association between weather conditions and stroke incidence has been a subject of interest for several years, yet the findings from various studies remain inconsistent. Additionally, predictive modelling in this context has been infrequent. This study explores the relationship of extremely high ischaemic stroke incidence and meteorological factors within the Slovak population. Furthermore, it aims to construct forecasting models of extremely high number of strokes.

METHODS

Over a five-year period, a total of 52,036 cases of ischemic stroke were documented. Days exhibiting a notable surge in ischemic stroke occurrences (surpassing the 90th percentile of historical records) were identified as extreme cases. These cases were then scrutinized alongside daily meteorological parameters spanning from 2015 to 2019. To create forecasts for the occurrence of these extreme cases one day in advance, three distinct methods were employed: Logistic regression, Random Forest for Time Series, and Croston's method.

RESULTS

For each of the analyzed stroke centers, the cross-correlations between instances of extremely high stroke numbers and meteorological factors yielded negligible results. Predictive performance achieved by forecasts generated through multivariate logistic regression and Random Forest for time series analysis, which incorporated meteorological data, was on par with that of Croston's method. Notably, Croston's method relies solely on the stroke time series data. All three forecasting methods exhibited limited predictive accuracy.

CONCLUSIONS

The task of predicting days characterized by an exceptionally high number of strokes proved to be challenging across all three explored methods. The inclusion of meteorological parameters did not yield substantive improvements in forecasting accuracy.

The impact of environmental conditions on non-communicable diseases in sub-Saharan Africa: A scoping review of epidemiologic evidence

Background

The burden of non-communicable diseases (NCDs) in sub-Saharan Africa (SSA) is increasing. Environmental conditions such as heavy metals and air pollution have been linked with the incidence and mortality of chronic diseases such as cancer, as well as cardiovascular and respiratory diseases. We aimed to scope the current state of evidence on the impact of environmental conditions on NCDs in SSA.

Methods

We conducted a scoping review to identify environmental conditions linked with NCDs in SSA by identifying studies published from January 1986 through February 2023. We searched African Index Medicus, Ovid Medline, Scopus, Web of Science, and Greenfile. Using the PICOS study selection criteria, we identified studies conducted in SSA focussed on physical environmental exposures and incidence, prevalence, and mortality of NCDs. We included only epidemiologic or quantitative studies.

Results

We identified 6754 articles from electronic database searches; only 36 met our inclusion criteria and were qualitatively synthesised. Two studies were conducted in multiple SSA countries, while 34 were conducted across ten countries in SSA. Air pollution (58.3%) was the most common type of environmental exposure reported, followed by exposure to dust (19.4%), meteorological variables (13.8%), heavy metals (2.7%), soil radioactivity (2.7%), and neighbourhood greenness (2.7%). The examined NCDs included respiratory diseases (69.4%), cancer (2.7%), stroke (5.5%), diabetes (2.7%), and two or more chronic diseases (19.4%). The study results suggest an association between environmental exposures and NCDs, particularly for respiratory diseases. Only seven studies found a null association between environmental conditions and chronic diseases.

Conclusions

There is a growing body of research on environmental conditions and chronic diseases in the SSA region. Although some cities in SSA have started implementing environmental monitoring and control measures, there remain high levels of environmental pollution. Investment can focus on improving environmental control measures and disease surveillance.

Environmental Factors and Hyperacute Stroke Care Activity During the COVID-19 Pandemic: An Interrupted Time-Series Analysis

BACKGROUND AND AIMS

Concerns have arisen regarding patient access and delivery of acute stroke care during the COVID-19 pandemic. We investigated key population level events on activity of the three hyperacute stroke units (HASUs) within Greater Manchester and East Cheshire (GM & EC), whilst adjusting for environmental factors.

METHODS

Weekly stroke admission & discharge counts in the three HASUs were collected locally from Emergency Department (ED) data and Sentinel Stroke National Audit Programme core dataset prior to, and during the emergence of the COVID-19 pandemic (Jan 2020 to May 2020). Whilst adjusting for local traffic-related air pollution and ambient measurement, an interrupted time-series analysis using a segmented generalised linear model investigated key population level events on the rate of stroke team ED assessments, admissions for stroke, referrals for transient ischaemic attack (TIA), and stroke discharges.

RESULTS

The median total number of ED stroke assessments, admissions, TIA referrals, and discharges across the three HASU sites prior to the first UK COVID-19 death were 150, 114, 69, and 76 per week. The stable weekly trend in ED assessments and stroke admissions decreased by approximately 16% (and 21% for TIAs) between first UK hospital COVID-19 death (5th March) and the implementation of the Act-FAST campaign (6th April) where a modest 4% and 5% increase per week was observed. TIA referrals increased post Government intervention (23rd March), without fully returning to the numbers observed in January and February. Trends in discharges from stroke units appeared unaffected within the study period reported here.

CONCLUSION

Despite adjustment for environmental factors stroke activity was temporarily modified by the COVID-19 pandemic. Underlying motivations within the population are still not clear. This raises concerns that patients may have avoided urgent health care risking poorer short and long-term health outcomes.

Seasonality of stroke: Winter admissions and mortality excess: A Thailand National Stroke population database study

OBJECTIVES

We examined the existence and potential burden of seasonality of stroke admissions and mortality within a tropical climate using cohort data collected between 1 st November 2003 and 31 st October 2012.

PATIENTS AND METHODS

In a prospective cohort of hospitalised stroke patients from the catchment of ∼75 % of the Thai population (n = 569,307; mean SD age = 64(14.5)), incident stroke admissions, in-hospital mortality, prolonged hospitalisations, and stroke related complications by season were determined. Rates of incident stroke admissions by month and season were plotted. Winter excess indexes for study outcomes expressed as a percentage were calculated. Using logistic regression we examined the association between winter admission and in-hospital mortality (non-winter admission as reference) adjusting for age, sex, stroke type, year of admission, and presence of pre-existing comorbidities.

RESULTS

We observed a winter excess in mortality during hospitalisation (+10.3 %) and prolonged length of stay (+7.3 %). Respective winter excess indexes for dyslipidaemias, arrhythmias, anaemia, and alcohol related disorders in patients that died during hospitalisation were +1.4 %, +6.2 %, +0.2 %, +1.5 %. In these patients, respective winter excess indexes for post-stroke complications of pneumonia and sepsis were +6.7 % and +3.2 %. In fully adjusted analyses, winter admission (compared to non-winter admission) was associated with increased odds of in-hospital mortality (OR (95 % CI) = 1.023 (1.006-1.040)).

CONCLUSIONS

We provide robust evidence for the existence of an excess in winter stroke admissions and subsequent in-hospital deaths within a tropical region.

Effect of seasonal and temperature variation on hospitalizations for stroke over a 10-year period in Brazil

BACKGROUND

Seasonal variation in stroke incidence remains controversial.

AIMS

We aimed to describe the pattern of seasonality in hospitalizations for stroke in Brazil.

METHODS

We evaluated age-adjusted hospitalization rates for stroke per month using data from the Brazilian Unified Healthcare System and median monthly temperature data obtained from the National Institute of Meteorology. To detect a seasonality pattern in time series, we used seasonal-trend decomposition using LOESS. We calculated a seasonal strength statistic and used Kruskal-Wallis test to evaluate the presence of seasonality in Brazil and its five regions. We also assessed the association of temperature and stroke hospitalization rates using Spearman's rho correlation.

RESULTS

We identified 1,422,496 stroke-related hospitalizations between 2009 and 2018. Mean age was 67 years, 51% were male and 77.5% of stroke diagnoses were not specified as ischemic or hemorrhagic. Median temperature was 23.8℃ (IQR 22.3-24.4). Age-adjusted hospitalizations demonstrated significant seasonal variation during all the years analyzed, with increased rates during the winter. When regional differences were analyzed, seasonal behavior was present in the south, southeast and northeast regions of the country. These were also the regions with lower median temperatures during the winter months and greater amplitude of average temperatures between warmer and colder months.

CONCLUSIONS

In this large national cohort of stroke patients in Brazil, we demonstrated the presence of seasonal variation in the age-adjusted hospitalization rate, with peak rates during the winter months. The regional gradient of incidence of stroke was directly associated with colder winters and greater amplitude of temperature.

Being Conscious of Water Intake Positively Associated with Sufficient Non-Alcohol Drink Intake Regardless of Seasons and Reasons in Healthy Japanese; the KOBE Study: A Cross Sectional Study

The present study sought to clarify if being conscious of water intake (CWI) is associated with sufficient non-alcohol drink (NAD) intake. We used data of healthy participants without diabetes, aged 40–74 years, in the Kobe Orthopedic and Biomedical Epidemiologic (KOBE) study. The association between being CWI and NAD intake was evaluated by multivariate linear regression analyses after adjusting for age, sex, surveyed months (seasons), alcohol drinking, health-awareness life habits, socioeconomic factors, serum osmolarity, estimated daily salt intake, and reasons for NAD intake. Among 988 (698 women and 290 men) participants eligible for the present analyses, 644 participants (65.2%) were CWI and 344 participants (34.8%) were not CWI (non-CWI). The most popular reason for being CWI was to avoid heat stroke in summer and to prevent ischemic cerebral stroke in winter. The CWI group took more NAD, especially decaffeinated beverages, than the non-CWI group (1846.7 ± 675.1 mL/day vs. 1478.0 ± 636.3 ml/day, p < 0.001). There was a significant association between being CWI and NAD intake in multivariate linear regression analyses ever after adjusting for the relevant variables (β = 318.1, p < 0.001). These findings demonstrated CWI, regardless of the reasons and the seasons, was associated with high NAD intake in Japanese healthy population.

Seasonal variation in the occurrence of ischemic stroke: A meta-analysis

Stroke was demonstrated to correlate with seasonal variation. However, the relevant studies were incongruous. To better understand the rules of seasonal impact on ischemic stroke (IS) patients, we performed this meta-analysis. We systematically searched relevant observational studies in Pubmed, Web of science and Embase from January 1, 1980, to November 1, 2017, in English. Patients included in this study were adults who suffered from IS. Stata version 12.0 software was used to pool useful data and calculate incidence rate ratios (IRRs) and their 95% confidence intervals (CIs). We also performed heterogeneity and sensitivity analyses and evaluated publication bias. Thirty-three observational studies involving 234,196 participants were incorporated into the meta-analysis. Summer and December were regarded as reference, respectively. The IRRs were calculated showing: IRR_Winter 1.05 (95% CI 1.04-1.07), IRR_Autumn 1.03 (95% CI 1.02-1.04), IRR_Spring 1.02 (95% CI 1.01-1.03). No obvious difference existed among 12 months. Stratified analyses on Köppen classification were also conducted. Between-study heterogeneity was discovered; however, predefined stratified analyses and meta-regression could not reduce this heterogeneity. Our meta-analysis has revealed very little seasonal variation in the overall study. Both cold and hot months may be high risky for IS after stratified by Köppen Climate Classification. Thus, a rationale to environmental setting of risky patient management could be provided. More studies with specific assessments are warranted for further comprehensive investigation.

Seasonal variation of admission severity and outcomes in ischemic stroke - a consecutive hospital-based stroke registry

Different morbidities and mortalities of ischemic stroke may occur among seasons. For detecting the seasonal variations of severity after stroke onset and prognosis, we employed a retrospective analysis on a prospective regional hospital-based stroke registry and included a total of 1039 consecutive patients with onset date from January 2014 to December 2015. Patients were divided into four groups according to the onset seasons. Baseline characteristics, stroke subtypes, admission National Institute of Health Stroke Scale (NIHSS) score and modified Rankin Scale (mRS) score in 90 d were recorded and compared. Ordinal logistic regression was used to evaluate the association of seasons and severity or outcomes. Higher proportion of cardiac embolisms appeared in spring and winter (p < 0.001). The median admission NIHSS score was 5 in spring, 3 in summer, 4 in fall and 4 in winter (p = 0.036). After 90 d from onset, 40.5% of patients in spring suffered poor outcome (mRS 3-6), while 24.6% in summer, 33.9% in fall and 40.1% in winter (p < 0.001). After adjusted for age, sex, stroke subtypes and other covariates, patients in spring and winter had 1.76 times (95%CI 1.14-2.70, p = 0.010) and 1.53 times (95%CI 1.08-2.18, p = 0.017) the risk of suffering higher severity category than patients in summer, respectively. Compared with summer group, risk of worse outcomes at 90 d increased to 2.30 times in spring (95%CI 1.53-3.45, p < 0.001), 1.57 times in fall (95%CI 1.14-2.16, p = 0.006) and 2.09 times in winter (95%CI 1.50-2.91, p < 0.001), respectively. In conclusion, onset seasons were associated with severity and outcomes in ischemic stroke, and patients admitted in spring and winter had more severity and worse outcomes than patients in summer.

The Effects of Various Weather Conditions as a Potential Ischemic Stroke Trigger in Dogs

Stroke is the fifth leading cause of death in the United States, and is the leading cause of serious, long-term disability worldwide. There are at least 795,000 new or recurrent strokes each year, and approximately 85% of all stroke occurrences are ischemic. Unfortunately, companion animals are also at risk for ischemic stroke. Although the exact incidence of ischemic stroke in companion animals is unknown, some studies, and the veterinary information network (VIN), report that approximately 3% of neurological case referrals are due to a stroke. There is a long list of predisposing factors associated with the risk of ischemic stroke in both humans and canines; however, these factors do not explain why a stroke happens at a particular time on a particular day. Our understanding of these potential stroke “triggers” is limited, and the effect of transient environmental exposures may be one such “trigger”. The present study investigated the extent to which the natural occurrence of canine ischemic stroke was related to the weather conditions in the time-period immediately preceding the onset of stroke. The results of the present study demonstrated that the change in weather conditions could be a potential stroke trigger, with the strokes evaluated occurring after periods of rapid, large fluctuations in weather conditions. There are currently no epidemiological data on the seasonal variability of ischemic stroke in dogs, and determining whether canine stroke parallels human stroke would further validate the use of companion dogs as an appropriate naturally occurring model.

Seasonal and Monthly variation in stroke and its subtypes-10 Year Hospital-Based Study

Background and Objectives:

There is no evidence of long-term studies of seasonal variations in stroke in Iran. Hence, the aim of this study was to determine the seasonal and monthly variation of 28-day mortality in Isfahan, Iran.

Methods:

From 2003 to 2013, In a Hospital-based retrospective study which was conducted by Isfahan Cardiovascular Research Center(ICRC), 24186 cases with first-ever stroke were recruited. Multinomial logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for seasonal and monthly 28-day mortality for stroke in general and three subtypes of stroke including intracranial hemorrhage (ICH), ischemic (IS) and subarachnoid hemorrhage (SAH).

Results:

In this study, unadjusted and adjusted odds ratios of seasonal 28-day mortality of stroke was highest in the winter and lowest in the summer. Although, differences were not statistically significant. For total and IS stroke, the unadjusted 28-day mortality ratio (UMR) was significant in February (1.19, 95% CI 1.00 -1.42, P= 0.04) as compared to March. Whereas after adjusted, for total stroke, 28-day mortality was significantly lowest in May (0.746, 95% CI 0.575-0.97, p=0.029), June (0.777, 95% CI 0.60-0.99, p=0.49) and July (0.771, 95% CI 0.59-0.99 p=0.049) as compared to March. The AMR between months were not significant in SAH and IS.

Conclusion:

Our findings demonstrate clear obvious monthly variation of 28-day mortality of stroke and its subtypes in Isfahan but no seasonal variations were observed.

Cerebral Venous Sinus Thrombosis May Follow a Seasonal Pattern

BACKGROUND

Several studies have demonstrated seasonal and temporal variations in the incidence of arterial stroke; however, for cerebral venous sinus thrombosis (CVST), such study seems lacking. The main aim of this study was to investigate whether there is any seasonal variation for CVST, and association between CVST occurrence and temperature.

METHODS

This retrospective study was conducted from January 2004 to July 2015 in 2 referral centers for the patients with cerebrovascular disorders. One hundred and sixty-six consecutive patients with a hospital admission or discharge diagnosis of definite CVST were included. The incidence of CVST was compared between high-temperature and low-temperature months.

RESULTS

The mean age of patients was 36.71 ± 12.44 and 130 (78.31%) subjects were female. The highest frequency of CVST was seen in 3 months of July to September (1.69/month per year); and the lowest frequency of CVST was seen from December to April (.83/month per year). Additionally, there was a significant correlation between the mean average of temperature in each month and the frequency of CVST occurrence (r = .60, P = .03). Moreover, we found a cluster of patients, mostly females, in whom CVST occurred in cold months and accompanied visible cerebral infarct with higher occurrence of seizure, focal neurological deficit, and loss of consciousness.

CONCLUSIONS

It seems that the incidence of CVST increases in high-temperature months of the year and dehydration and ensuing consequences may play an important role in such augmentation; however, the visible cerebral infarct is again more observed in low-temperature months.

Time series analysis of the association between ambient temperature and cerebrovascular morbidity in the elderly in Shanghai, China

Research on the association between ambient temperature and cerebrovascular morbidity is scarce in China. In this study, we applied mixed generalized additive model (MGAM) to daily counts of cerebrovascular disease of Shanghai residents aged 65 years or older from 2007-2011, stratified by gender. Weighted daily mean temperature up to lags of one week was smoothed by natural cubic spline, and was added into the model to assess both linear and nonlinear effects of temperature. We found that when the mean temperature increased by 1 °C, the male cases of cerebrovascular disease reduced by 0.95% (95% Confidence Interval (CI): 0.80%, 1.10%) or reduced by 0.34% (95% CI: -0.68, 1.36%) in conditions of temperature was below or above 27 °C. However, for every 1 °C increase in temperature, the female cases of cerebrovascular disease increased by 0.34% (95% CI: -0.26%, 0.94%) or decreased by 0.92% (95% CI: 0.72, 1.11%) in conditions of temperature was below or above 8 °C, respectively. Temperature and cerebrovascular morbidity is negatively associated in Shanghai. MGAM is recommended in assessing the association between environmental hazards and health outcomes in time series studies.

The relationship between ischemic stroke and weather conditions in Duzce, Turkey

BACKGROUND

Weather conditions are thought to increase the risk of stroke occurrence. But their mechanism has not yet been clarified. We investigated possible relationships between ischemic stroke and weather conditions including atmospheric pressure, temperature, relative humidity, and wind speed.

METHODS

One hundred and twenty-eight patients with ischemic stroke who had been admitted to our hospital between January 1 and December 31, 2010 were enrolled in this study. We investigated the relationship between daily cases and weather conditions the same day or 1, 2, and 3 days before stroke.

RESULTS

A negative correlation was found between maximum wind speed and daily cases 3 days before stroke. As the relationship between daily cases and changes of weather conditions in consecutive days was evaluated, a negative correlation was found between daily cases and change of atmospheric pressure in the last 24 hours.

CONCLUSIONS

The maximum wind speed 3 days before stroke and change of atmospheric pressure in the last 24 hours were found to increase the cases of ischemic stroke. We recommend that individuals at risk of ischemic stroke should pay more attention to preventive measures, especially on days with low maximum wind speed, on subsequent 3 days, and on days with low atmospheric pressure in the last 24 hours.

Triggering of stroke by ambient temperature variation: a case-crossover study in Maputo, Mozambique

OBJECTIVES

The effect of ambient temperature as a stroke trigger is likely to differ by type of stroke and to depend on non-transient exposures that influence the risk of this outcome. We aimed to quantify the association between ambient temperature variation and stroke, according to clinical characteristics of the events, and other risk factors for stroke.

METHODS

We conducted a case-crossover study based on a 1-year registry of the hospital admissions due to newly occurring ischemic and hemorrhagic stroke events in Maputo, Mozambique's capital city (N=593). The case-period was defined as the 7 days before the stroke event, which was compared to two control periods (14-21 days and 21-28 days before the event). We computed humidity- and precipitation-adjusted odds ratios (OR) and 95% confidence intervals (95%CI) using conditional logistic regression.

RESULTS

An association between minimum temperature declines higher than 2.4 °C in any two consecutive days in the previous week and the occurrence of stroke was observed only for first events (OR=1.43, 95%CI: 1.15-1.76). Stronger and statistically significant associations were observed for hemorrhagic stroke (OR=1.50, 95%CI: 1.07-2.09) and among subjects not exposed to risk factors, including smoking, high serum cholesterol or atrial fibrillation. No differences in the effect of temperature were found according to the patients' vital status 28 days after the event.

CONCLUSIONS

First stroke events, especially of the hemorrhagic type, were triggered by declines in the minimum temperature between consecutive days of the preceding week.

Seasonal differences and circadian variation in stroke occurrence and stroke subtypes

BACKGROUND

India is a subtropical country with clear seasonal variations in weather conditions. Seasonal and circadian variation in occurrence of subtypes of cerebrovascular disease has been of interest in several studies from different countries and climate zones, but discrepant results have made the conclusions unclear. The aim of the present study was to observe the seasonal and circadian variation in the occurrence of stroke and its subtypes among our population.

METHODS

This was a cross-sectional observational study based on new cases and past cases of stroke on follow-up, conducted between January 2011 and December 2012 in the Department of Neurology, at the All India Institute of Medical Sciences, New Delhi, India. The date and time of onset of the stroke was recorded. The categorization of months into season was in accordance with the Indian Meteorological Department guidelines. The time of onset was distributed into 6 hourly intervals. Statistical calculations were performed using Stata version 12.1 and SPSS version 20.

RESULTS

A total of 583 patients were included for the study. The rate of occurrence of stroke was highest in the late morning 0600-1159 hours (P value <.001) compared with other times of the day, regardless of gender or age for both ischemic and hemorrhagic strokes. It was lowest in late evening (1800-2359 hours) quadrant compared with other quadrants. Although there was no significant difference found by dichotomizing the groups into two 6-month periods, there was an increasing trend in number of patients with stroke during the months November-February. There was no difference in stroke occurrence between the types of stroke or within each type among different seasons with different temperatures. Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification of ischemic strokes also did not show any association with season or circadian rhythm.

CONCLUSIONS

There is a significant increase in occurrence of strokes between 0600 and 1159 hours and lowest between 1800-2359 hours. No significant variation in stroke occurrence or subtype for any of the seasons was observed.