Self-controlled Case Series Design Research Articles

Antibiotic Prophylaxis and Infective Endocarditis Incidence Following Invasive Dental Procedures

The association between antibiotic prophylaxis and infective endocarditis after invasive dental procedures is still unclear. Indications for antibiotic prophylaxis were restricted by guidelines beginning in 2007. To systematically review and analyze existing evidence on the association between antibiotic prophylaxis and infective endocarditis following invasive dental procedures. PubMed, Cochrane-CENTRAL, Scopus, Web of Science, Proquest, Embase, Dentistry and Oral Sciences Source, and ClinicalTrials.gov were systematically searched from inception to May 2023. Studies on the association between antibiotic prophylaxis and infective endocarditis following invasive dental procedures or time-trend analyses of infective endocarditis incidence before and after current antibiotic prophylaxis guidelines were included. Study quality was evaluated using structured tools. Data were extracted by independent observers. A pooled relative risk (RR) of developing infective endocarditis following invasive dental procedures in individuals who were receiving antibiotic prophylaxis vs those who were not was computed by random-effects meta-analysis. The outcome of interest was the incidence of infective endocarditis following invasive dental procedures in relation to antibiotic prophylaxis. Of 11 217 records identified, 30 were included (1 152 345 infective endocarditis cases). Of them, 8 (including 12 substudies) were either case-control/crossover or cohort studies or self-controlled case series, while 22 were time-trend studies; all were of good quality. Eight of the 12 substudies with case-control/crossover, cohort, or self-controlled case series designs performed a formal statistical analysis; 5 supported a protective role of antibiotic prophylaxis, especially among individuals at high risk, while 3 did not. By meta-analysis, antibiotic prophylaxis was associated with a significantly lower risk of infective endocarditis after invasive dental procedures in individuals at high risk (pooled RR, 0.41; 95% CI, 0.29-0.57; P for heterogeneity = .51; I2, 0%). Nineteen of the 22 time-trend studies performed a formal pre-post statistical analysis; 9 found no significant changes in infective endocarditis incidence, 7 demonstrated a significant increase for the overall population or subpopulations (individuals at high and moderate risk, streptococcus-infective endocarditis, and viridans group streptococci-infective endocarditis), whereas 3 found a significant decrease for the overall population and among oral streptococcus-infective endocarditis. While results from time-trend studies were inconsistent, data from case-control/crossover, cohort, and self-controlled case series studies showed that use of antibiotic prophylaxis is associated with reduced risk of infective endocarditis following invasive dental procedures in individuals at high risk, while no association was proven for those at low/unknown risk, thereby supporting current American Heart Association and European Society of Cardiology recommendations. Currently, there is insufficient data to support any benefit of antibiotic prophylaxis in individuals at moderate risk.

A self-controlled case series study to measure the risk of SARS-CoV-2 infection associated with attendance at sporting and cultural events: the UK Events Research Programme events

BackgroundIn 2021, whilst societies were emerging from major social restrictions during the SARS-CoV-2 pandemic, the UK government instigated an Events Research Programme to examine the risk of COVID-19 transmission from attendance at cultural events and explore ways to enable people to attend a range of events whilst minimising risk of transmission. We aimed to measure any impact on risk of COVID-19 transmission from attendance at events held at or close to commercially viable capacity using routinely collected data.MethodsData were obtained on attendees at Phase 3 Events Research Programme events, for which some infection risk mitigation measures were in place (i.e. evidence of vaccination or a negative lateral flow test). Attendance data were linked with COVID-19 test result data from the UK Test and Trace system. Using a self-controlled case series design, we measured the within person incidence rate ratio for testing positive for COVID-19, comparing the rate in days 3 to 9 following event attendance (high risk period) with days 1 and 2 and 10–16 (baseline period). Rate ratios were adjusted for estimates of underlying regional COVID-19 prevalence to account for population level fluctuations in infection risk, and events were grouped into broadly similar types.ResultsFrom attendance data available for 188,851 attendees, 3357 people tested positive for COVID-19 during the observation period. After accounting for total testing trends over the period, incidence rate ratios and 95% confidence intervals for positive tests were 1.16 (0.53–2.57) for indoor seated events, 1.12 (0.95–1.30) for mainly outdoor seated events, 0.65 (0.51–0.83) for mainly outdoor partially seated events, and 1.70 (1.52–1.89) for mainly outdoor unseated multi-day events.ConclusionsFor the majority of event types studied in the third phase of the UK Events Research Programme, we found no evidence of an increased risk of COVID-19 transmission associated with event attendance. However, we found a 70% increased risk of infection associated with attendance at mainly outdoor unseated multi-day events. We have also demonstrated a novel use for self-controlled case series methodology in monitoring infection risk associated with event attendance.

Risk of Cardiovascular Events After Influenza: A Population-Based Self-Controlled Case Series Study, Spain, 2011–2018

Abstract This study explores the relationship between influenza infection, both clinically diagnosed in primary care and laboratory confirmed in hospital, and atherothrombotic events (acute myocardial infarction and ischemic stroke) in Spain. A population-based self-controlled case series design was used with individual-level data from electronic registries (n = 2 230 015). The risk of atherothrombotic events in subjects ≥50 years old increased more than 2-fold during the 14 days after the mildest influenza cases in patients with fewer risk factors and more than 4-fold after severe cases in the most vulnerable patients, remaining in them more than 2-fold for 2 months. The transient increase of the association, its gradient after influenza infection, and the demonstration by 4 different sensitivity analyses provide further evidence supporting causality. This work reinforces the official recommendations for influenza prevention in at-risk groups and should also increase the awareness of even milder influenza infection and its possible complications in the general population.

Comparison design and evaluation power in cohort and self-controlled case series designs for post-authorization vaccine safety studies.

Post-authorization safety studies (PASSs) of vaccines are important. PASSs enable the evaluation of association between vaccination and adverse events following immunization through common study designs. Clinical trials during vaccine development typically include a few thousand to 10,000 participants while a PASS might aim to detect a few adverse events per 100,000 vaccine recipients. While all available data may be utilized, prior consideration of power analyses are nonetheless crucial for interpretation in cases where statistically significant differences are not found. This research primarily examined cohort study design and self-controlled case series (SCCS) design, estimating the power of a PASS under plausible conditions. Both the cohort study and SCCS designs necessitated large sample sizes or high event counts to guarantee adequate power. The SCCS design is particularly suited to evaluating rare adverse events. However, extremely rare events may not yield sufficient occurrences, thereby resulting in low power. Although the SCCS design can more efficiently control for time-invariant confounding in principle, it solely estimates relative measures. A cohort study design might be preferred if confounding can be adequately managed as it also estimates absolute measures. It may be an easy decision to use all the data at hand for either design. We found it necessary to estimate the sample size and number of events to be used in the study based on a priori information and anticipated results.

Immune thrombocytopenic purpura and Guillain-Barré syndrome after 23-valent pneumococcal polysaccharide vaccination in Japan: The vaccine effectiveness, networking, and universal safety (VENUS) study

BackgroundTo address the lack of an active vaccine safety surveillance system in Japan, the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study was initiated in 2021 as a pilot system using existing health insurance claims data and vaccination records. MethodsThis study evaluated the value of the VENUS study by assessing the incidence of immune thrombocytopenic purpura (ITP) and Guillain-Barré syndrome (GBS) following vaccination with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using a self-controlled case series (SCCS) design. ResultsIncidence rate ratios for ITP during 28-day and 42-day risk periods were 0.89 (95% confidence interval [CI], 0.12–6.4), and 0.58 (95% CI, 0.081–4.2), respectively. Neither was statistically significant. Incidence rate ratios could not be estimated for GBS due to the limited sample size. ConclusionThe VENUS study can provide valuable insights to facilitate the establishment of an advanced vaccine monitoring system in Japan.

Adverse events after first and second doses of COVID-19 vaccination in England: a national vaccine surveillance platform self-controlled case series study.

To estimate the incidence of adverse events of interest (AEIs) after receiving their first and second doses of coronavirus disease 2019 (COVID-19) vaccinations, and to report the safety profile differences between the different COVID-19 vaccines. We used a self-controlled case series design to estimate the relative incidence (RI) of AEIs reported to the Oxford-Royal College of General Practitioners national sentinel network. We compared the AEIs that occurred seven days before and after receiving the COVID-19 vaccinations to background levels between 1 October 2020 and 12 September 2021. England, UK. Individuals experiencing AEIs after receiving first and second doses of COVID-19 vaccines. AEIs determined based on events reported in clinical trials and in primary care during post-license surveillance. A total of 7,952,861 individuals were vaccinated with COVID-19 vaccines within the study period. Among them, 781,200 individuals (9.82%) presented to general practice with 1,482,273 AEIs. Within the first seven days post-vaccination, 4.85% of all the AEIs were reported. There was a 3-7% decrease in the overall RI of AEIs in the seven days after receiving both doses of Pfizer-BioNTech BNT162b2 (RI = 0.93; 95% CI: 0.91-0.94) and 0.96; 95% CI: 0.94-0.98), respectively) and Oxford-AstraZeneca ChAdOx1 (RI = 0.97; 95% CI: 0.95-0.98) for both doses), but a 20% increase after receiving the first dose of Moderna mRNA-1273 (RI = 1.20; 95% CI: 1.00-1.44)). COVID-19 vaccines are associated with a small decrease in the incidence of medically attended AEIs. Sentinel networks could routinely report common AEI rates, which could contribute to reporting vaccine safety.

Risk of injuries before and after a diagnosis of cirrhosis: A population-based cohort study.

Cirrhosis is often asymptomatic prior to decompensation. Still, cognitive impairment and sarcopenia may be present before decompensation, possibly increasing the risk of injuries. We estimated the risk of injuries during the period shortly before and after cirrhosis diagnosis. All patients (N=59,329) with a diagnosis of cirrhosis from 1997 to 2019 were identified from the Swedish National Patient Register. We used a self-controlled case series design to compare the incidence rates (IR) of injuries during a "diagnostic period" (within 3 months before or after the cirrhosis diagnosis date) to a self-controlled "prediagnostic period" (the same 6 calendar months 3 years before diagnosis), using conditional Poisson regression. Injuries were ascertained from the National Patient Register. We identified 23,733 (40.0%) patients with compensated and 35,595 (60.0%) with decompensated cirrhosis. There were 975 injuries (IR 2.8/1000 person-months) during the prediagnostic period, and 3610 injuries (IR 11.6/1000 person-months) identified during the diagnostic period. The IR ratio was 8.1 (95% CI 7.5-8.7) comparing the diagnostic period with the prediagnostic period. For patients with compensated cirrhosis, the risk increment of injuries was highest just before the diagnosis of cirrhosis, whereas the risk increase was highest shortly after the diagnosis for those with decompensation. The incidence of injuries increases shortly before and after the diagnosis of cirrhosis. These findings indicate that cirrhosis is frequently diagnosed in conjunction with an injury, and highlight the need for injury prevention after cirrhosis diagnosis, especially in patients with decompensation.

Risk of lymphadenopathy from SARS-CoV-2 vaccination in Korea: a self-controlled case series analysis.

To assess the risk of lymphadenopathy following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. A self-controlled case series design was used to determine whether the risk of lymphadenopathy was higher in the 1-day to 42-day risk interval after coronavirus disease 2019 (COVID-19) vaccination compared to the control period. In addition, subgroup analyses were conducted according to baseline characteristics, time since vaccination, and sensitivity analyses adjusted for the length of the risk interval. The risk of developing lymphadenopathy in the risk interval (1-42 days) after COVID-19 vaccination compared to the control period was significantly increased, with a relative incidence (RI) of 1.17 (95% confidence interval [CI], 1.17 to 1.18) when the first, second, and third doses were combined. The RI was greater on the day of vaccination (1.47; 95% CI, 1.44 to 1.50). In subgroup analyses by baseline characteristics, a significantly increased risk or trend toward increased risk was observed in most subgroups except for those aged 70 years and older, with a significant increase in risk in younger individuals, those with a Charlson's comorbidity index <5, and those who received mRNA vaccines (mRNA-1273>BNT162b2). Within the 1-day to 42-day post-dose risk period, the relative risk was highest during the 1-day to 7-day post-dose period (1.59; 95% CI, 1.57 to 1.60) compared to the control period, and then the risk declined. In the sensitivity analysis, we found that the longer the risk window, the smaller the RI. SARS-CoV-2 vaccination is associated with a statistically significant increase in the risk of lymphadenopathy, and this risk was observed only with mRNA vaccines.

Risk of Guillain-Barré Syndrome Following COVID-19 Vaccines: A Nationwide Self-Controlled Case Series Study.

Guillain-Barré syndrome (GBS) has been inconsistently associated with some coronavirus disease 2019 (COVID-19) vaccines. We aimed to quantify the risk of GBS according to the type of COVID-19 vaccine in a large population. Using the French National Health Data System linked to the COVID-19 vaccine database, we analyzed all individuals aged 12 years or older admitted for GBS from December 27, 2020, to May 20, 2022. We estimated the relative incidence (RI) of GBS within 1-42 days after vaccination up to the first booster dose compared with baseline periods using a self-controlled case series design. We then derived the number of cases attributable to the vaccination. Analyses were adjusted for the period and stratified by age group, sex, and for the presence of severe acute respiratory syndrome coronavirus 2 or common acute infections. Of 58,530,770 people aged 12 years or older, 88.8% received at least 1 COVID-19 vaccine dose and 2,229 were hospitalized for GBS during the study period. Patients had a median age of 57 years, and 60% were male patients. The RI of GBS between 1-42 days was 2.5 (95% CI 1.8-3.6) for the first dose of ChAdOx1-S and 2.4 (95% CI 1.2-5.0) for the unique dose of Ad26.COV2.S vaccine. We estimated 6.5 attributable GBS cases per million persons having received a first dose of ChAdOx1-S and 5.7 cases per million for the Ad26.COV2.S vaccine. Except for the age group of 12-49 years after the second dose of the messenger RNA (mRNA)-1273 vaccine (RI 2.6, 95% CI 1.2-5.5), none of the RI estimates were found significantly increased for the mRNA vaccines. In summary, we found increased risks of GBS after the first administration of ChAdOx1-S and Ad26.COV2.S vaccines. In this comprehensive assessment at the French population level, there was no statistically significant increase in the risk of GBS after the administration of mRNA vaccines. This is reassuring in the context of the ongoing and future use of mRNA-based booster vaccination.

Reduced Asthma Exacerbations in Adult Patients Treated With Bronchial Thermoplasty.

Bronchial thermoplasty (BT) has been shown to be effective in randomized controlled trials of patients with severe asthma who failed to achieve disease control with high-dose inhaled corticosteroids combined with bronchodilators. However, the effectiveness of BT in real-world clinical settings, especially among the Asian population, has not been determined. To evaluate the effectiveness of BT using a nationwide database. Using the inpatient and outpatient data from the Japanese Diagnosis Procedure Combination database, we applied a self-controlled case series design to evaluate changes in the composite outcome of hospital admissions and emergency department visits, as well as systemic corticosteroid dose, between 1 year before and after BT. We also conducted subgroup analyses based on patients' profiles. Among the 561 patients with asthma who underwent BT treatment between September 2014 and March 2020, 102 patients with at least 1 outcome were analyzed. Bronchial thermoplasty was significantly associated with an improvement in the composite outcome of hospital admission and emergency department visits (incidence rate ratio 0.53; 95% CI 0.44-0.64). Systemic corticosteroid use was reduced after BT sessions (1931.5 mg [1,341.2-3,725.3 mg] to 641.3 mg [134.2-1,691.1 mg] per person-year; P < .001). Although all groups showed a significant improvement in the composite outcome in the subgroup analyses, BT tended to be less effective among people older than 65 years and those with higher body mass index (>25 kg/m2). The present study using real-world data suggests that BT may improve asthma control; however, the effectiveness of BT can vary depending on patient baseline profiles.

Impact of Concomitant Use of Proton Pump Inhibitors and Clopidogrel on Recurrent Stroke and Myocardial Infarction.

Conflicting results have been reported regarding the interaction between proton pump inhibitors (PPIs) and clopidogrel. We investigated whether concomitant PPI use influenced the risk of recurrence in patients with stroke and myocardial infarction (MI). This study used two databases for two different designs, the Korean National Health Insurance Service (NHIS) database for a self-controlled case series design, and the national sample cohort of the NHIS data base converted to the Observational Medical Outcomes Partnership-Common Data Model version for a cohort study based on large-scale propensity score matching. In the PPI co-prescription group, recurrent hospitalization with stroke occurred in 17.6% of the 8201 patients with history of stroke, and recurrent MI occurred in 17.1% of the 1216 patients with history of MI within1 year. According to the self-controlled case series, the overall relative risk (RR) of recurrent stroke was 2.09 (95% confidence interval (CI); 1.83-2.38); the RR showed an increasing trend parallel to the time from the beginning of PPI co-prescription. In the cohort study, there was a higher incidence of recurrent stroke in the PPI co-prescription group (Hazard ratio (HR): 1.34, 95% CI: 1.01-1.76, p = 0.04). The overall RR of recurrent MI was 1.47 (95% CI; 1.02-2.11) in the self-controlled case series; however, there was no statistically significant difference in recurrent MI in the cohort study (HR:1.42, 95% CI:0.79-2.49, p = 0.23). The impact of individual PPIs on stroke and MI showed different patterns. A PPI co-prescription >4 weeks with clopidogrel was associated with hospitalization of recurrent stroke within 1 year of initial diagnosis; however, its association with recurrent MI remains inconclusive. The influence of individual PPIs should be clarified in the future.

Risk of Noninfectious Uveitis after Coronavirus Disease 2019 Vaccination in a United States Claims Database

To assess noninfectious uveitis (NIU) risk after coronavirus disease 2019 (COVID-19) vaccination in patients without a history of uveitis. A retrospective matched cohort study and self-controlled case series (SCCS) analysis using a longitudinal data asset with claims data from the OptumLabs Data Warehouse from December 11, 2020, through November 30,2021. The matched cohort analysis included patients continuously enrolled for 730 days before December 11, 2020, who received a COVID-19 vaccination during the study period. This COVID-19-vaccinated group was matched to a COVID-19-unvaccinated historical cohort enrolled in 2018 and 2019. The SCCS design included individuals from the vaccinated cohort who experienced an NIU event during the study period. Enrollees with a history of uveitis were excluded. Hazard ratios (HRs) were calculated using Cox proportional hazards models in the matched cohort design. Incidence rate ratios (IRRs) comparing NIU incidence in exposed risk periods after vaccination and unexposed control periods within individuals were calculated using conditional Poisson regression models in the SCCS design. Models were adjusted for age, recent receipt of non-COVID-19 vaccinations, corticosteroid or immunosuppressive use, and smoking history. Subgroup analyses were conducted by vaccination type and age group. Rates of NIU identified with International Classification of Diseases, Tenth Revision, codes. The matched cohort analysis included 4 611 378 patients, with 2 305 689 per cohort. The adjusted HR comparing NIU incidence in the COVID-19-vaccinated and unvaccinated cohort was 0.91 (95% confidence interval [CI], 0.75-1.10; P= 0.33). The SCCS analysis included 686 patients. The IRR comparing NIU risk after vaccination with risk during control intervals was 1.05 (95% CI, 0.89-1.23; P= 0.57). An increased risk was found in the subgroup aged 5 to 44 years (IRR, 1.40; 95% CI, 1.04-1.87; P= 0.024). The matched cohort and SCCS analyses did not detect increased NIU risk after COVID-19 vaccination overall in individuals without history of uveitis, providing reassurance about the vaccine's safety. The finding of increased risk in the youngest subgroup suggests heightened immune responses in younger individuals, warranting further investigation. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Heavy bleeding and other menstrual disturbances in young women after COVID-19 vaccination

BackgroundMany signals of menstrual disturbances as possible side effects of vaccination against COVID-19 have been reported. Our objective was to compare the risk of menstrual disturbances before and after vaccination among women aged 18–30 years in Oslo, Norway. MethodsWe used electronic questionnaires to collect reports of menstrual disturbances from 3972 women aged 18–30 years, participating in the population-based Norwegian Young Adult Cohort. We examined the occurrence of menstrual disturbances (heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, longer interval between menstruations, spot bleedings, stronger pain during menstruation, period pain without bleeding) before and after the first and second dose of COVID-19 vaccine. Relative risks (RR) according to vaccination were estimated using a self-controlled case-series design. We performed additional analyses stratified by vaccine brand, contraception/hormone use, and presence of gynecological condition(s). ResultsThe prevalence of any menstrual disturbance was 36.7 % in the last menstrual cycle prior the first vaccine dose. The RR for heavier bleeding than usual was 1.90 (95 % CI: 1.69–2.13) after the first vaccine dose and 1.84 (95 % CI 1.66–2.03) after the second dose. Increased risks of prolonged bleeding, shorter interval between menstruations, and stronger pain during menstruation were also observed after both doses. The RRs did not differ with vaccine brand, contraception/hormone use, or presence of gynecological condition(s) for any of the menstrual disturbances. ConclusionMenstrual disturbances were common regardless of vaccination. We found increased risk of menstrual disturbances after vaccination, particularly for heavier bleeding than usual, prolonged bleeding, shorter interval between menstruations, and stronger period pain. In the future, menstrual characteristics should be included in vaccine trials.

Safety of COVID-19 booster dose: is the juice worth the squeeze?

Safety of COVID-19 booster dose: is the juice worth the squeeze?

Proton pump inhibitor use and risk of pneumonia: a self-controlled case series study.

Recent research indicates that use of proton pump inhibitors (PPIs) is associated with pneumonia, but existing evidence is inconclusive because of methodological issues. This study aimed to answer whether PPI-use increases risk of pneumonia while taking the methodological concerns of previous research into account. This population-based and nationwide Swedish study conducted in 2005-2019 used a self-controlled case series design. Data came from national registries for medications, diagnoses, and mortality. Conditional fixed-effect Poisson regression provided incidence rate ratios (IRR) with 95% confidence intervals (CI) for pneumonia comparing PPI-exposed periods with unexposed periods in the same individuals, thus controlling for confounding. Analyses were stratified by PPI-treatment duration, sex, age, and smoking-related diseases. Use of histamine type-2 receptor antagonists (used for the same indications as PPIs) and risk of pneumonia was analysed for assessing the validity and specificity of the results for PPI-therapy and pneumonia. Among 519,152 patients with at least one pneumonia episode during the study period, 307,709 periods of PPI-treatment occurred. PPI-use was followed by an overall 73% increased risk of pneumonia (IRR 1.73, 95% CI 1.71-1.75). The IRRs were increased across strata of PPI-treatment duration, sex, age, and smoking-related disease status. No such strong association was found between histamine type-2 receptor antagonist use and risk of pneumonia (IRR 1.08, 95% CI 1.02-1.14). PPI-use seems to be associated with an increased risk of pneumonia. This finding highlights a need for caution in using PPIs in individuals with a history of pneumonia.

Risk of Major Adverse Cardiovascular Event Following Incident Hospitalization for Acute Gout: A Western Australian Population-Level Linked Data Study.

Cardiovascular disease is the most common cause of death in people with gout. Acute inflammation, which is a characteristic of gout, may have a mechanistic role in major adverse cardiovascular events (MACEs). We aimed to examine the relationship between admissions to a hospital with acute gout and MACEs in a large population-based data set. We extracted data from the Hospital Morbidity Data Collection and Death Registrations of the Western Australian Rheumatic Disease Epidemiology Registry. We identified patients admitted to hospital with incident acute gout and who had admissions or a death record because of MACEs. We compared the risk of MACEs during the postdischarge period (1-30 days after acute gout admission) and control period (365 days prior to admission and 365 days after the postdischarge period) using a self-controlled case-series (SCCS) design, which is a within-person design that controls for time-invariant patient-specific confounding. We performed conditional fixed-effects Poisson regression to obtain rate ratios (RRs). We identified 941 patients (average age: 76.4 years; SD: 12.6; 66.7% male) with an incident acute gout admission and documented MACEs during the control and/or postdischarge periods. Of the 941 patients, 898 (95%) experienced MACEs during the combined control period (730-day period) and 112 (12%) during the postdischarge period (30-day period). The rates of MACEs during the total control and postdischarge periods were 0.84 and 1.45 events per person-year, respectively. Regression analysis confirmed increased rate during the postdischarge period (RR: 1.67; 95% CI: 1.38-2.03) compared with the control period. Sensitivity analyses indicated that our results were robust in relation to known limitations of the SCCS design. We report an increased risk of MACEs in the first 30 days after an incident hospital admission with acute gout, suggesting a temporal association between acute inflammation and subsequent MACEs in patients with gout.

Individual trigger factors for hemorrhagic stroke: Evidence from case-crossover and self-controlled case series studies.

Hemorrhagic stroke (HS) is a sudden-onset disease with high mortality and disability rates, and it is crucial to explore the triggers of HS. In this study, we analyzed individual triggers for HS to provide a basis for HS prevention and intervention. A systematic search of five databases was conducted until December 2022. Studies on HS-related individual triggers conducted using a case-crossover study or self-controlled case series design were included in the descriptive summary and comprehensive evidence synthesis of each trigger. A total of 39 studies were included after the screening, and 32 trigger factor categories were explored for associations. Potential trigger factors for HS were as follows: Antiplatelet (odd ratio (OR), 1.10; 95% confidence interval (CI), 1.00-1.21) and anticoagulant (OR, 5.43; 95% CI, 2.04-14.46) medications, mood stabilizers/antipsychotics (OR, 1.33; 95% CI, 1.07-1.65), infections (OR, 2.15; 95% CI, 1.73-2.67), vaccinations (relative risk, 1.11; 95% CI, 1.02-1.21), physical exertion (OR, 2.08; 95% CI, 1.58-2.74), cola consumption (OR, 5.45; 95% CI, 2.76-10.76), sexual activity (OR, 7.49; 95% CI, 2.23-25.22), nose blowing (OR range, 2.40-56.40), defecation (OR, 16.94; 95% CI, 3.40-84.37), and anger (OR, 3.59; 95% CI, 1.56-8.26). No associations were observed with illicit drug use (OR, 2.05; 95% CI, 0.52-8.06) or cigarette smoking (OR, 0.81; 95% CI, 0.52-1.24) and HS. Individual triggers, including several medications, infections, vaccinations, and behaviors, may trigger HS onset. Direct control measures for behavioral triggers can play a crucial role in preventing HS. High-risk populations should receive personalized therapies and monitoring measures during the medication treatment to balance the risk of acute HS and the basic diseases.

COVID-19 vaccine side effects on menstrual disturbances among Iranian women

BackgroundMany studies reported of menstrual disturbances as possible side effects of COVID-19 vaccination. Our objective was to evaluate the association between vaccination and the occurrence of menstrual disturbances among Iranian women. MethodsWe used to google form questionnaires to collect reports of menstrual disturbances from 455 women aged 15–55 years in Iran. We estimated the relative risk of menstrual disturbances according to vaccination in a self-controlled case-series design after vaccination. We examined the occurrence of such disorders after the first, second and third doses of vaccine. ResultsFindings The prevalence of menstrual disturbance was more in latency and heavy bleeding than others disorder after vaccination, although ֮ %50 of women doesn't have any disturbance. We observed increased risks after vaccination also for other menstrual disturbances, in menopausal women too (>10%). DiscussionMenstrual disturbances were generally common regardless of vaccination. We found a significant increase in menstrual disturbances after vaccination, particularly for latency and heavier bleeding than usual, longer duration and for short interval between menstruations. Mechanisms underlying these findings may involve bleeding disturbances in general, as well as endocrine alterations of immune system stimulation and relation to hormonal secretion.

Risk of death following COVID-19 vaccination or positive SARS-CoV-2 test in young people in England

Several studies have reported associations between COVID-19 vaccination and risk of cardiac diseases, especially in young people; the impact on mortality, however, remains unclear. We use national, linked electronic health data in England to assess the impact of COVID-19 vaccination and positive SARS-CoV-2 tests on the risk of cardiac and all-cause mortality in young people (12 to 29 years) using a self-controlled case series design. Here, we show there is no significant increase in cardiac or all-cause mortality in the 12 weeks following COVID-19 vaccination compared to more than 12 weeks after any dose. However, we find an increase in cardiac death in women after a first dose of non mRNA vaccines. A positive SARS-CoV-2 test is associated with increased cardiac and all-cause mortality among people vaccinated or unvaccinated at time of testing.

Lack of association between febrile seizures and vaccines containing diphtheria, tetanus, and acellular pertussis in Chinese children

ABSTRACT Background The association between the administration of vaccines containing diphtheria, tetanus, and acellular pertussis (DTaP) and febrile seizures (FSs) is unclear. This study aimed to evaluate the risk of FSs after the administration of DTaP-containing vaccines in Chinese children aged 1 to 23 months. Research design and methods A self-controlled case series (SCCS) design was adopted based on data from the Ningbo Regional Health Information Platform (NRHIP). The observation period was from 1 to 23 months of age. The relative incidences (RIs) within 0 to 3 days, 4 to 7 days, and 0 to 7 days after the administration of DTaP-containing vaccines were estimated. The remaining observation period was the control period. Results The RIs within 0 to 3 days, 4 to 7 days, and 0 to 7 days after any dose of DTaP-containing vaccines were 1.14 (95% CI 0.86 to 1.52), 0.89 (95% CI 0.65 to 1.23), and 1.02 (95% CI 0.82 to 1.26), respectively. Conclusions This study provides reassuring evidence that there is no increased risk of FSs immediately after the administration of DTaP-containing vaccines, which might serve to reassure both professionals and families with regard to the risk of FSs associated with DTaP-containing vaccines.