Monthly variations in aneurysmal subarachnoid hemorrhage incidence and mortality: Correlation with weather and pollution

Abstract

Background and purposeAlthough the effect of weather and air pollution on the occurrence of subarachnoid hemorrhage (SAH) has been investigated, results have remained inconsistent. The present study aimed to determine the seasonality of aneurysmal subarachnoid hemorrhage occurrence and mortality.MethodsWe used the National Inpatient Sample database to evaluate the effect of meteorological factors and air pollutants on patients with subarachnoid hemorrhage in Korea between 2011 and 2014. Monthly variations in SAH occurrence and mortality were analyzed using locally weighted scatter plot smoothing curves. Multivariate Poisson generalized linear regression models were used to evaluate potential independent meteorological and pollutant variables associated with SAH occurrence and mortality.ResultsIn total, 21,407 patients who underwent clip or coil treatment owing to aneurysmal SAH in Korea from January 1, 2011, to December 31, 2014, were included. The crude incidence rate of SAH in Korea was 10.5 per 100,000 people per year. An approximately 0.5% lower risk of SAH was observed per 1°C increase in mean monthly temperature (relative risk, 0.995; 95% confidence interval [CI], 0.992–0.997; p < 0.001), while an approximately 2.3% higher risk of SAH was observed per 1°C increase in mean monthly diurnal temperature.ConclusionsWe showed distinct patterns of seasonal and monthly variation in the occurrence and mortality of SAH. Our findings suggest that meteorological factors may play an important role in monthly variations in the occurrence of aneurysmal SAH.

Relationship between Circadian Variation in Ictus of Aneurysmal Subarachnoid Hemorrhage and Physical Activity

“…In this study, diurnal variation of onset time of aSAH, specifically a bimodal distribution, was observed, and this diurnal variation was also seen in all subgroups. These findings are analogous to other studies around the world that show an increase in the frequency in the morning [6,7,9,10,16,20,21,23]. In addition, there was a preponderance in the morning hours, regardless of age, sex, or other traditional risk factors, which was also in accordance with the findings of most previous reports [6,13,21,23].…”

Stroke Seasonality and Weather Association in a Middle East Country: A Single Tertiary Center Experience

“…On the other hand, several studies linked the weather or seasonal variations with stroke incidence ( 4 – 6 , 9 , 10 , 13 – 15 , 23 , 24 ). Locally, in Qatar, Salam et al reported a significant relationship between seasonal variation and incidence of IS relative to ICH in summer ( 4 ).…”

“…Researchers were unable to produce consistent results if the weather can directly impact a person's health condition. However, some studies showed a link between weather and stroke risk (4)(5)(6)(9)(10)(11)(12)(13)(14)(15)(16). On the other hand, different observational studies and a meta-analysis showed the opposite (7,9,16,17).…”

Relationship between Social Distancing and Admissions for Cerebrovascular Accidents at a Tertiary Medical Center during the COVID-19 Pandemic: A Retrospective, Community-Based Study

“…Considering several diseases wax and wane with the seasons, this factor was included in the analysis. The seasons’ definition was followed by the previous study as spring (March to May), summer (June to August), fall (September to November), and winter (December to February) [ 14 ]. These seasons are referred to as Korean climate change.…”