Seasonal Variation In Incidence Research Articles

Trends in the Incidence of Disseminated Cryptococcosis in Japan: A Nationwide Observational Study, 2015–2021

BackgroundCryptococcus species can cause severe disseminated infections in immunocompromised hosts. This study investigated the epidemiological features and trends in disseminated cryptococcosis in Japan.MethodsWe used publicly available Infectious Diseases Weekly Reports to obtain data on the incidence of disseminated cryptococcosis in Japan from 2015 to 2021. Patient information, including age, sex, and regional and seasonal data, were extracted. The Joinpoint regression program was used to determine the age-adjusted incidence rate (AAR) per 100,000 population, annual percentage change (APC), and average APC (AAPC).ResultsA total of 1047 cases of disseminated cryptococcosis were reported, of which those aged ≥ 70 years accounted for 68.8%. The AAR in men was significantly higher than that in women (median: 0.13 vs. 0.09: p = 0.0024). APC for the overall cases increased by 9.9% (95% confidence interval [95% CI] − 5.4–27.7) from 2015 to 2018 and then decreased by 3.3% (95% CI − 15.5–10.7) from 2018 to 2021. AAPC for the entire study period was 3.1% (95% CI − 1.5–8.0), indicating a possible increase in its number, although not statistically significant. In terms of regional distribution, the average AAR was highest in Shikoku District (0.17) and lowest in Hokkaido District (0.04). Northern Japan exhibited a significantly lower median AAR (median [interquartile range]: 0.06 [0.05, 0.08]) than the Eastern (0.12 [0.12, 0.13]), Western (0.11 [0.10, 0.13]), and Southern (0.14 [0.12, 0.15]) regions. No seasonal variation in incidence was observed.ConclusionThe prevalence of disseminated cryptococcosis has not increased in Japan. Geographically, the incidence is lower in Northern Japan. Further investigations that incorporate detailed clinical data are required.

Seasonal variation in the incidence of primary intracerebral hemorrhage: a 16-year nationwide analysis.

Data on nationwide trends and seasonal variations in the incidence of Intracerebral Hemorrhage (ICH) in the United States (US) are lacking. We used the Nationwide Inpatient Sample (2004-2019) and Census Bureau data to calculate the quarterly (Q1:January-March; Q2:April-June; Q3:July-September; Q4:October-December) incidence rates (IR) of adult (≥18 years) ICH hospitalizations, aggregated across Q1-Q4 and Q2-Q3. We report adjusted incidence rate ratios (aIRR) and 95% confidence intervals (CI) for differences in the quarterly incidence of ICH, as compared to acute ischemic stroke (AIS), between Q1Q4 and Q2Q3 using a multivariable Poisson regression model. We additionally performed stratified analyses across the four US regions. Among 822,143 (49.0% female) ICH and 6,266,234 (51.9% female) AIS hospitalizations, the average quarterly crude IR of ICH was consistently higher in Q1Q4 compared to Q2Q3 (5.6 vs. 5.2 per 100,000) (aIRR, CI: 1.09, 1.08-1.11)-this pattern was similar across all four US regions. However, a similar variation pattern was not observed for AIS incidence. The incidence (aIRR, CI) of both ICH (1.01, 1.00-1.02) and AIS (1.03, 1.02-1.03) is rising. Unlike AIS, ICH incidence is consistently higher in colder quarters, underscoring the need for evaluation and prevention of factors driving seasonal variations in ICH incidence.

Seasonal variation in gestational diabetes mellitus among women in Norway: a national population-based study

ObjectivesPrevious research on seasonal variation in the incidence of gestational diabetes mellitus (GDM) has shown inconclusive results. Furthermore, little is known about whether a seasonal variation in GDM might be...

Abstract 165: Nationwide Seasonal Variations And Increases In Incidence Of Intracerebral Hemorrhage And Acute Ischemic Stroke: An Analysis Of Pre-pandemic 16-year National Data

Introduction: There is paucity of evidence on long-term nationwide trends and seasonal variation in incidence of Intracerebral Hemorrhage (ICH) and Acute Ischemic Stroke (AIS). Methods: Using the Nationwide Inpatient Sample (2004 - 2019), we identified adults (≥ 18 years) discharged with primary diagnosis of ICH and AIS. We aggregated hospitalizations across quarters: Jan - Mar (Q1); Apr - Jun (Q2); Jul - Sep (Q3) and Oct - Dec (Q4). We used survey weights to calculate nationally representative estimates of quarter-specific incidence across age, sex, and race/ethnicity sub-cohorts and obtained time-specific denominators from the US Census Bureau. We calculated per quarter incidence rate (IR) across Q1-Q4 and Q2-Q3. We used multivariable Poisson regression model to report the adjusted incidence rate ratio (aIRR) and 95% confidence interval (CI) for the differences in quarterly incidence between Q1Q4 and Q2Q3. Results: Across 16 years, 985 959 ICH and 7 067 178 AIS hospitalizations were evaluated. The average quarterly crude IR of ICH in Q1Q4 of 6 per 100 000 was higher than the average rate of 5.4 per 100 000 observed in Q2Q3 (aIRR, CI: 1.10, 1.09 - 1.10). However, for AIS the average quarterly IR of ICH in Q1Q4 (41.2 per 100 000) was similar to the incidence rate in Q2Q3 (41.2 per 100 000) (aIRR, CI: 1.00, 1.00 - 1.00). Furthermore, we observed that average quarterly incidence is increasing overtime (aIRR, CI) for both ICH (1.01, 1.01 - 1.01) and AIS (1.03, 1.03 -1.03). The aIRR and CI for age, race, and sex are provided in the figure. Conclusion: Both stroke phenotypes demonstrate an increasing nationwide incidence. However, unlike AIS, ICH incidence is consistently and significantly higher in the months of October to March. Additional evaluation of factors such as holiday stress, seasonal variations in health behaviors (diet, physical activity, medication adherence) and physiological parameters (blood pressure, blood viscosity, fibrinogen, and cholesterol levels) is warranted.

Chronic villitis of unknown aetiology: an Australian institution's 5-year experience

Villitis of unknown aetiology (VUE) is a chronic inflammatory condition of the placenta that is associated with increased morbidity and mortality in perinatal medicine. The cause remains elusive and recent studies have explored immune-mediated, infectious and environmental triggers in the pathogenesis of VUE. The objective of this study was to identify the characteristics of VUE diagnoses at Mater Mothers' Hospital over a 5-year period, including any association with seasons, maternal age and histological patterns of the disorder. We retrospectively reviewed reports for placentas sent to Mater Pathology, Brisbane, over 5 years (December 2015 to November 2020). Case level data were retrieved including maternal age, the month of delivery, gestational age, parity, VUE status, recurrence, histopathological subtype and grade. Univariable and multivariable logistic regression was used to estimate the unadjusted and adjusted association between VUE and season, maternal age and trimester at delivery. While more placentas were examined during summer than winter (p=0.005), there was no evidence of seasonal variation in the incidence of VUE over the 5 years (p=0.17). Both univariable and multivariable logistic regression analyses showed that VUE increased with maternal age (p<0.001) and gestational age (9.8% of examined placentas in the third trimester compared to 2.1% in first and second trimesters, p<0.001). Seven of 714 women with VUE (0.98%) had one or more recurrences of the condition within the study period. Of these, VUE was of lower grade in two of the three women who were prescribed aspirin in the subsequent pregnancy. Furthermore, basal VUE without basal myometrial fibres (6.6%), was over-represented among clinically morbidly adherent placentas (MAP) reported in this cohort. Our study does not show evidence of a seasonal variation in VUE incidence. The immune-mediated pathogenesis of VUE is favoured, with our data showing increased rates of the condition as maternal age increases.

An Exploration of How Solar Radiation Affects the Seasonal Variation of Human Mortality Rates and the Seasonal Variation in Some Other Common Disorders.

Many diseases have large seasonal variations in which winter overall mortality rates are about 25% higher than in summer in mid-latitude countries, with cardiovascular diseases and respiratory infections and conditions accounting for most of the variation. Cancers, by contrast, do not usually have pronounced seasonal variations in incidence or mortality rates. This narrative review examines the epidemiological evidence for seasonal variations in blood pressure, cardiovascular disease rates and respiratory viral infections in relation to atmospheric temperature and humidity, and solar UV exposure through vitamin D production and increased blood concentrations of nitric oxide. However, additional mechanisms most likely exist by which solar radiation reduces the risk of seasonally varying diseases. Some studies have been reported with respect to temperature without considering solar UV doses, although studies regarding solar UV doses, such as for respiratory infections, often consider whether temperature can affect the findings. More research is indicated to evaluate the relative effects of temperature and sun exposure on the seasonality of mortality rates for several diseases. Since solar ultraviolet-B (UVB) doses decrease to vanishingly small values at higher latitudes in winter, the use of safe UVB lamps for indoor use in winter may warrant consideration.

Seasonal Variation in Incidence of Stroke in a General Population of 1.4 Million Japanese: The Shiga Stroke Registry

Introduction: The purpose of this study was to investigate seasonal variation in stroke incidence using data from a large-scale stroke registry of general population in current Japan. Methods: Shiga Stroke Registry (SSR) is an ongoing population-based registry of stroke that occurred in the Shiga Prefecture in central Honshu, Japan. A total 6,688 cases of first-ever stroke, with onset dates ranging from 1 January 2011 to 31 December in 2013 were included in this study. Incidence rates of first-ever stroke in each season were estimated using the person-year approach and adjusted for age and sex using the Poisson regression models. Results: From 2011 to 2013, we identified a total of 6,688 stroke cases (3,570 men, 3,118 women), of which 4,480 cases had ischemic stroke (2,518 men, 1,962 women), 1,588 had intracerebral hemorrhage (857 men, 731 women) and 563 had subarachnoid hemorrhage (166 men, 397 women). Age- and sex-adjusted incidence rates of total stroke were 151 (95% confidence interval [CI] 144–160, p = <0.001 vs. summer) in spring, 130 (95% CI 122–137) in summer, 141 (95% CI 133–149, p = 0.020 vs. summer) in autumn and 170 (95% CI 161–179, p = <0.001 vs. summer) in winter. Seasonal variation was more pronounced in intracerebral hemorrhage than in ischemic stroke. Conclusion: In the present large-scale stroke registry of general population, incidence rates of stroke were highest in winter and lowest in summer in current Japan.

Seasonal variation in incidence and outcomes of out of hospital cardiac arrest: A retrospective national observational study in the United States.

Out of hospital cardiac arrest (OHCA) remains a leading cause of mortality among adults in the United States. Environmental impact on incidence and outcomes of OHCA has not been fully investigated in recent years. Previous studies showed a possible increase in incidence and mortality in winter season and during seasons with temperature extremes. This study examines seasonal variation in incidence and outcomes of OHCA in the United States.Retrospective study of adult OHCA using the Nationwide Emergency Department Sample was carried out. Monthly incidence rate per 100,000 ED presentations was calculated. Survival rates for each month of admission were examined by hospital region. Multivariate analyses were conducted to determine the effect of the season and month of admission on survival.A total of 122,870 adult OHCA cases presented to emergency departments (EDs) in 2014 and were included. Average incidence of OHCA cases was 147 per 100,000 ED presentations. Overall survival rate in the study population was 5.6% (95% confidence intervals [CI] = 5.4%–5.9%). Patients had an average age of 65.5 (95% CI: 65.3–65.7) years and were mainly men (61.8%). Rates of OHCA presentations were highest during December and January (9.9% and 10.0%) while survival rates were lowest during December (4.6%) and highest in June (6.9%). Regional variation in OHCA outcomes was also noted with highest average survival rate in West (7.8%) and lowest in South (4.3%). After adjusting for confounders including region of hospital, Summer season (Ref: all other seasons), and more specifically month of June (Ref: all other months) were found to be positively associated with survival (OR 1.27, 95% CI [1.07–1.52], P-value = .008) and (OR 1.43, 95% CI [1.08–1.89], P-value = .012 respectively).Incidence and outcomes of out of hospital cardiac arrest presentations to the emergency departments in the United States have seasonal variation. Both incidence and mortality of OHCA increase during colder months, and survival is significantly higher in summer season or in June. Exploring how to use this variation to improve outcomes through refresher training of medical providers or through other mitigation plans is needed.

Temporal and seasonal variations in incidence of stage II and III NEC-a 28-year epidemiologic study from tertiary NICUs in Connecticut, USA.

To investigate seasonality and temporal trends in the incidence of NEC. A retrospective cohort study from two tertiary NICUs in northern and central Connecticut involving 16,761 infants admitted over a 28-year period. Various perinatal and neonatal risk factors were evaluated by univariate, multivariate, and spectral density analyses. Incidence of NEC was unchanged over the 28 years of study. Gestational age, birth weight, and birth-months (birth in April/May) were independently associated with stage II or III NEC even after adjusting for confounding factors (p < 0.05). Yearly NEC incidence showed a multi-modal distribution with spectral density spikes approximately every 10 years. Temporal and seasonal factors may play a role in NEC with a peak incidence in infants born in April/May and periodicity spikes approximately every 10 years. These trends suggest non-random and possibly environmental factors influencing NEC.

An Association between Rainy Days with Clinical Dengue Fever in Dhaka, Bangladesh: Findings from a Hospital Based Study.

Background: Dengue, a febrile illness, is caused by a Flavivirus transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Climate influences the ecology of the vectors. We aimed to identify the influence of climatic variability on the occurrence of clinical dengue requiring hospitalization in Zone-5, a high incidence area of Dhaka City Corporation (DCC), Bangladesh. Methods and Findings: We retrospectively identified clinical dengue cases hospitalized from Zone-5 of DCC between 2005 and 2009. We extracted records of the four major catchment hospitals of the study area. The Bangladesh Meteorological Department (BMD) provided data on temperature, rainfall, and humidity of DCC for the study period. We used autoregressive integrated moving average (ARIMA) models for the number of monthly dengue hospitalizations. We also modeled all the climatic variables using Poisson regression. During our study period, dengue occurred throughout the year in Zone-5 of DCC. The median number of hospitalized dengue cases was 9 per month. Dengue incidence increased sharply from June, and reached its peak in August. One additional rainy day per month increased dengue cases in the succeeding month by 6% (RR = 1.06, 95% CI: 1.04–1.09). Conclusions: Dengue is transmitted throughout the year in Zone-5 of DCC, with seasonal variation in incidence. The number of rainy days per month is significantly associated with dengue incidence in the subsequent month. Our study suggests the initiation of campaigns in DCC for controlling dengue and other Aedes mosquito borne diseases, including Chikunguniya from the month of May each year. BMD rainfall data may be used to determine campaign timing.

S0381 Incidence and Seasonal Variation of Food Bolus Impaction in Patients With Underlying Eosinophilic Esophagitis

INTRODUCTION: Eosinophilic Esophagitis (EoE) is a chronic disorder of the esophagus characterized as a condition with esophageal symptoms such as dysphagia and an identifiable eosinophilic infiltrate on biopsies in the absence of other etiology. Studies into the reason for the recent rise in incidence and prevalence have discussed the environmental factors that may be associated with the disorder with the pathogenesis thought to be a combination of inflammatory and allergy mediated. In this setting, reports have found that cases can be provoked by aeroallergens and the observation of seasonal variation and geographic variation in presentation. The primary aim of this study was to search for a potential seasonal variation in the presentation of esophageal food bolus impaction in patients with EoE. METHODS: A retrospective analysis of endoscopies completed from May 2017 through April 2019 for foreign body removal or with food found in the esophagus was performed. The study identified a total of 177 cases with 19 cases of esophageal food bolus impaction in patients with established or newly identified EoE. Cases were analyzed regarding seasonal variation in incidence of food bolus impaction and demographic data and variables such as eosinophil count on biopsy and level of impaction were also analyzed using Fisher’s exact test. RESULTS: The overall incidence of esophageal food impaction in cases of EoE was higher in the winter with 10/19 (52.6%) of overall cases occurring in winter compared to 3/19 (15.8%) in other seasons although this did not reach statistical significance (P = 0.0561). 63.2% of the patients were male and 89.5% were white. The difference in eosinophil count and level of impaction did not significantly vary by season (P = 0.5885 and 0.4250). There were four observable strictures found in the group. CONCLUSION: In our study there was a higher incidence of food impaction in the winter season but this did not reach statistical significance. No difference was found in the magnitude of the eosinophilic infiltrate in biopsy specimens by season or by level of impaction. Previous studies have had differing findings on the role of aeroallergens in the pathophysiology and presentation of EoE as well as the presence of seasonal variation and the specific season. Due to these varied findings and small numbers in our study, ongoing evaluation is warranted to shed further light on the presence of possible seasonal variation and the impact environment has on EoE.Figure 1.: Esophageal Food Impaction by Season (P = 0.0561).Figure 2.: Eosinophil Count by Season.Figure 3.: Level of Impaction by Season (P = 0.4250).

Winter LVAD implantation is associated with adverse clinical outcomes.

The seasonal variation of incidence and severity of heart failure is well known. However, the impact of seasonal variation on clinical outcomes following left ventricular assist device (LVAD) implantation remains unknown. We retrospectively reviewed consecutive patients who received LVAD implantation between January 2014 and December 2016 along with their first year of post-implant outcomes. Clinical outcomes were compared between those with winter LVAD implantation (between October and March) and those with non-winter LVAD implantation. 168 patients with a median age of 57 years and 130 males were included. There was no seasonal difference in the number of LVAD implantations. One-year survival free from major adverse events was significantly lower in the winter implant group (n = 88) compared to the non-winter group (n = 80) (44% vs 61%) with an adjusted hazard ratio of 1.81 (95% confidence interval 1.11-2.90, p = 0.014), largely due to a higher rate of heart failure readmission in the winter implant patients (incidence rate ratio 2.29, 95% confidence interval 0.89-5.84). Patients who underwent LVAD implantation during the winter season had a higher heart failure readmission rate. A detailed mechanism and therapeutic strategy given our findings warrant further investigation.

Seasonal variation in incidence and causal organism of surgical site infection after PLIF/TLIF surgery: A multicenter study

BackgroundPostoperative SSI is a common and potentially serious complication in spine surgery. Seasonal variation occurs in rates of nosocomial infection, with higher rates found in the summer, during which hot, humid conditions may be optimal for proliferation of bacteria. This might also influence the rate of SSI. The purpose of the study was to examine seasonal variation in SSI after PLIF/TLIF surgery, including relationships with experience of surgeons and causal organisms. MethodsCases with SSI after PLIF/TLIF surgery at 10 facilities between January 1, 2012, and December 31, 2014 were retrieved from a database. Infection was defined based on CDC guidelines for SSIs. Patients were followed for at least two years after surgery. Surgeries were examined in spring (April–June), summer (July–September), autumn (October–December), and winter (January–March). Seasonal variation and other factors with a potential association with SSIs were evaluated. ResultsA total of 1174 patients (607 males, 567 females) who underwent PLIF/TLIF surgery were identified. The operations were PLIF (n = 667), TLIF (n = 443), MIS-PLIF (n = 27), and MIS-TLIF (n = 37). The total SSI rate for the 2-year period was 2.5% (29/1174), and the 2-year average SSI rates for surgeries in each season were spring, 2.6% (7/266); summer, 3.9% (13/335); fall, 1.3% (4/302); winter, 1.8% (5/271). The SSI rate was significantly higher in summer than non-summer (3.9% vs. 1.9%, p < 0.05). SSIs were caused by a variety of pathogens, including Gram-positive cocci, and Staphylococcus aureus was the most common pathogenic organism to cause SSI. ConclusionSeasonality should be taken into account in strategies for SSI prevention, with particular attention on mitigation of increased temperature and humidity in the summer and on infection caused by Gram-positive cocci and S. aureus.

Influence of climate variables on the rising incidence of nontuberculous mycobacterial (NTM) infections in Queensland, Australia 2001–2016

International reports indicate a rising incidence of nontuberculous mycobacterial (NTM) disease. Many infectious diseases have seasonal variation in incidence, and major weather events and climate change have been implicated. The aim of this study was to explore the relationship between climate variables and NTM incident cases in Queensland, Australia. MethodsNTM data were obtained from the Queensland notifiable conditions database for the period 2001–2016. Rainfall and temperature data were obtained from the Australian Bureau of Meteorology. Poisson regression models were used to assess notification rates (incidence cases per 100,000 population) over time and to estimate incidence rate ratios (IRR). Cross correlation coefficients were used to examine the relationship between rainfall and temperature data and NTM incidence over time in each Hospital and Health Service (HHS). Results12,219 NTM cases were reported. The most common species was M. intracellulare (39.1%), followed by M. avium (9.8%), M abscessus (8.5%), M. fortuitum (8.3%), M. chelonae (3.3%), and M. kansasii (2.4%). The estimated incidence rate increased from 11.10 (95% CI 8.10–15.22) in 2001 to 25.88 (95%CI 21.78–30.73) per 100,000 in 2016. The estimated IRR increased for all common species, except M. kansasii. Although increased IRRs were observed for most NTM species, geospatial heterogeneity was observed. The effect of rainfall and temperature on NTM incidence differed between species and geographic regions. ConclusionsThe incidence of NTM infections increased between 2001 and 2016. Variations in temperature and rainfall may play a role in environmental exposure to some species of NTM. Spatial variation in IRR suggests that there may also be other environmental factors that influence transmission.

Seasonal Variation in Incidence of Anti-GQ1b Antibody Syndrome – A Population-based Study (472)

Seasonal Variation in Incidence of Anti-GQ1b Antibody Syndrome – A Population-based Study (472)

Retrospective chart review: seasonal variation in incidence of bolus impaction is maintained and statistically significant in subgroups with atopy and eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition with eosinophilic infiltration of the esophageal mucosa. The most prominent symptom is dysphagia, which may result in esophageal bolus impaction in need of surgical extraction. To investigate whether an earlier reported seasonal variation in esophageal bolus impaction present only in a subgroup of patients with EoE and atopic disorders could be confirmed in this larger study. A single center retrospective chart review of patients who were diagnosed with esophageal bolus impaction between January 2004 and December 2017 was performed. Clinical, epidemiological and histologic data were collected. A total of 755 cases with esophageal bolus impaction were reviewed. A significantly higher occurrence of soft bolus impaction in summer and fall was shown in cases with confirmed EoE and in cases with atopy but not in the nonatopic group or in the group with a negative biopsy result. EoE was found in 48% of biopsied patients. A significant seasonal variation in cases with esophageal bolus impaction and concomitant atopy and EoE is confirmed, but the study design does not allow a causative role of allergens to be established.

Hip fractures in the winter – Using the National Hip Fracture Database to examine seasonal variation in incidence and mortality

We set out to examine the implications of seasonal variation in hip fracture for trauma services and for the frail older people who typically suffer this injury.Since 2007 the National Hip Fracture Database (NHFD) has been reporting data for all over-60 year old patients presenting in England, Wales and Northern Ireland. We analysed published NHFD data for the 450,764 people who presented during the seven years from April 2011 to March 2018.We found marked seasonal variation in the number of people presenting: 8% more people presenting in the winter months (December-February) than in the summer (June-August).The total number of people dying within 30 days of hip fracture was 30.5% higher among those presenting in these winter months. In total 33,649 people (7.5%) died within 30 days of hip fracture, but this figure varied significantly (p < 0.001, Chi2 test); ranging from 6.7% in July to 8.7% (30% higher) in January.The public health impact of these findings is significant. An 8% increase in hip fracture numbers during the winter would equate with 1250 additional fractures during these months each year. Patients average over 20 days in hospital, so these additional cases will compound the stresses on hospital services over the Christmas and New Year holiday period. Such factors must be taken into consideration when organising trauma services if we are to try and avoid the additional 325 deaths that we found to occur each winter.

Seasonal variations in incidence and maternal–fetal outcomes of gestational diabetes

AimsTo determine whether the neonatal and delivery outcomes of gestational diabetes vary seasonally in the context of a relatively cool temperate climate.MethodsA retrospect cohort of 23 735 women consecutively delivering singleton, live‐born term infants in a single tertiary obstetrics centre in the UK (2004–2008) was identified. A total of 985 (4.1%) met the diagnostic criteria for gestational diabetes. Additive dynamic regression models, adjusted for maternal age, BMI, parity and ethnicity, were used to compare gestational diabetes incidence and outcomes over annual cycles. Outcomes included: random plasma glucose at booking; gestational diabetes diagnosis; birth weight centile; and delivery mode.ResultsThe incidence of gestational diabetes varied by 30% from peak incidence (October births) to lowest incidence (March births; P=0.031). Ambient temperature at time of testing (28 weeks) was strongly positively associated with diagnosis (P<0.001). Significant seasonal variation was evident in birth weight in gestational diabetes‐affected pregnancies (average 54th centile June to September; average 60th centile December to March; P=0.027). Emergency Caesarean rates also showed significant seasonal variation of up to 50% (P=0.038), which was closely temporally correlated with increased birth weights.ConclusionsThere is substantial seasonal variation in gestational diabetes incidence and maternal–fetal outcomes, even in a relatively cool temperate climate. The highest average birth weight and greatest risk of emergency Caesarean delivery occurs in women delivering during the spring months. Recognizing seasonal variation in neonatal and delivery outcomes provides new opportunity for individualizing approaches to managing gestational diabetes.

P2653Seasonal variations of myocardial infarction and sex-specific differences in Germany

Abstract Background Ischemic heart disease (IHD) is the most common cause of death with an increasing frequency worldwide. It accounts for approximately 20% of all deaths in Europe and the United States of America. Approximately 1/3 of the IHD patients present with sudden cardiac death. The acute presentation of IHD myocardial infarction (MI) is a life-threatening, serious health problem, which causes substantially morbidity and mortality. It is well established that the onset of MI follows a circadian and seasonal periodicity. Seasonal variation regarding the incidence and the short-term mortality of acute MI was frequently reported, but data about sex-specific differences are sparse. Purpose Thus, our objectives were to investigate seasonal variations of myocardial infarction. Methods We analyzed the impact of seasons on incidence and in-hospital mortality of patients with acute MI in Germany from 2005 to 2015. We included all MI patients (ICD code I21) with an acute MI (, but not those MI patients with a recurrent event in the first 28 days after a previous MI (ICD code I22)), who were hospitalized in Germany between 2005 and 2015, in this analysis (source: RDC of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2005–2015, own calculations). Results The nationwide sample comprised 3,008,188 hospitalizations of patients with MI (2005–2015). The annual incidence was 334.7 per 100.000 population. Incidence inclined from 316.3 to 341.6 per 100.000 population per year (β 0.17 [0.10 to 0.24], P&lt;0.001), while in-hospital mortality rate decreased from 14.1% to 11.3% (β −0.29 [−0.30 to −0.28, P&lt;0.001). Overall, 377,028 (12.5%) patients died in-hospital. Seasonal variation of both incidence and in-hospital mortality were of substantial magnitude. Seasonal incidence (86.1 vs. 79.0 per 100.000 population per year, P&lt;0.001) and in-hospital mortality (13.2% vs. 12.1%, P&lt;0.001) were higher in the winter than in the summer saeson. Risk to die in winter was elevated (OR 1.080 (95% CI 1.069–1.091), P&lt;0.001) compared to summer season independently of sex, age and comorbidities. Reperfusion treatment with drug eluting stents and coronary artery bypass graft were more often used in summer. We observed sex-specific differences regarding the seasonal variation of in-hospital mortality: males showed lowest mortality in summer, while females during fall. Low temperature dependency of mortality seems more pronounced in males. Conclusions Incidence of acute MI increased 2005–2015, while in-hospital mortality rate decreased. Seasonal variations of incidence and in-hospital mortality were of substantial magnitude with lowest incidence and lowest mortality in the summer season. Additionally, we observed sex-specific differences regarding the seasonal variation of the in-hospital mortality. Acknowledgement/Funding This study was supported by the German Federal Ministry of Education and Research (BMBF 01EO1503)

P2822Seasonal variation in in-hospital cardiac arrest and associated mortality

Abstract Background Previous reports have documented seasonal variation in out-of-hospital cardiac arrest (OHCA), with peak incidence in winter months, regardless of geographical region. However, seasonal variation in in-hospital cardiac arrest (IHCA) has not been well studied. Purpose To assess seasonal variation in incidence of in-hospital cardiac arrest, as well as gender and mortality differences. Methods We queried the 2014 National Inpatient Service (NIS) database for the total numbers of inpatient hospitalizations and in-hospital cardiac arrests for each month, as identified by ICD-9 codes (99.60 and 99.63). The trend for each month was plotted to assess seasonal variations in hospitalizations, IHCA, and mortality. Seasonal Variations in IHCA Results The mean age of the study population was 57.3±0.2 years and 58.9% were female. Out of 29,717,872 total inpatient hospitalizations in 2014, the overall IHCA event for the year was 0.38%. Females were more likely to be hospitalized; however, males were more likely to have IHCA. These gender differences persisted throughout the year. Overall, more hospitalizations and IHCA were seen in the winter compared to the summer, and this trend was seen in both men and women. The highest incidence of in-hospital cardiac events occurred in January and the lowest incidence occurred in June. There was no seasonal variation in mortality in both male and female patients who suffered IHCA. Conclusion(s) In this observational study, seasonal variation is present in in-hospital cardiac arrest. Cardiac events are highest in the winter months as compared to the summer months; however, the mechanism of this variation is unknown and warrants further study. Acknowledgement/Funding None