Self-controlled Case Series Design Research Articles

Concomitant Use of Oral Anticoagulants with Oral Dipeptidyl Peptidase-4 Inhibitors and Serious Bleeding Events.

In a prior screening study, saxagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4i), was found to have an increased rate of serious bleeding when used concomitantly with several oral anticoagulants (OACs). We aimed to confirm or refute the associations between concomitant use of individual OACs and DPP-4is and serious bleeding in a large US database, using self-controlled case series (SCCS) and case-crossover (CCO) designs. The study population was eligible Medicare beneficiaries co-exposed to a DPP-4i (precipitant) and either an OAC (object drug) or lisinopril (negative control object drug) in 2016-2020. For the SCCS, we used conditional Poisson regression to estimate adjusted rate ratios (RRs) between each co-exposure (vs. not) and serious bleeding and divided the RR by the adjusted RR for the corresponding lisinopril + precipitant pair to obtain ratios of RRs (RRRs). For the CCO, we estimated the adjusted odds ratios (ORs) of exposure to the precipitant in the focal window vs. referent window using multivariable conditional logistic regression and divided the ORs in the object drug-exposed cases over the ORs in negative object drug-exposed cases to obtain the ratios of ORs (RORs). The adjusted RRRs for serious bleeding ranged from 0.32 (0.05-1.91) for apixaban/lisinopril + saxagliptin to 3.49 (1.29-9.48) for warfarin/lisinopril + linagliptin. The adjusted RORs ranged from 0.01 (0.00-0.20) for rivaroxaban/lisinopril + saxagliptin to 2.99 (0.74-12.11) for apixaban/lisinopril + linagliptin. While we could not confirm previously identified signals because of statistical imprecision, several numerically elevated estimates still warrant caution in concomitant use and further examination.

Cholinesterase Inhibitor Initiation Does Not Increase the Risk of Fall-Related Injury in Older Adults Treated with Beta-blockers: a self-controlled case series design.

Prescribing cholinesterase inhibitors (ChEIs) concurrently with beta-blockers might cause syncope that increases the risk of fall-related injuries (FRIs). This self-controlled case series study assesses the risk of FRIs associated with initiating ChEIs while receiving beta-blockers among Medicare fee-for-service-insured nursing home (NH) residents in the United States. We identified individuals at their first dispensing of a beta-blocker between 2016 and 2019 after at least 45 days of long-stay NH residency. Individuals were followed from the first day of beta-blocker use until beta-blocker discontinuation, Medicare disenrollment, death, or study end. ChEI initiation was classified as the first 60 days of new ChEI dispensing after 45 days of no ChEI exposure. FRIs were assessed during beta-blocker use periods and age-adjusted incidence rate ratios (IRR) for ChEI-initiation days versus other days were calculated using conditional Poisson regression models. Analyses were weighted for event-dependent observation periods due to the high risk of mortality after an FRI in this population. Subgroup analyses were conducted for several key time-fixed variables, including sex, age, ChEI type, ChEI dose, beta-blocker selectivity and beta-blocker dose. The FRI risk after ChEI initiation was not elevated among 837 residents who experienced an FRI while using beta-blockers (IRR=0.90 [95%CLs 0.71, 1.15]). Analyses of ChEI initiation in several subgroups yielded similar results. There was no substantial difference in FRI risk when initiating ChEIs among older NH residents receiving beta-blocker therapy versus periods without ChEI initiation, suggesting that there is no clinically significant pharmacodynamic drug-drug interaction between beta-blockers and ChEIs.

A Propensity Score Approach and a Partitioned Approach for the Self-Controlled Case Series Design to Evaluate Safety of a 2-dose Vaccine Series: Comment.

A Propensity Score Approach and a Partitioned Approach for the Self-Controlled Case Series Design to Evaluate Safety of a 2-dose Vaccine Series: Comment.

Acute Appendicitis After COVID-19 Vaccines in Italy: A Self-Controlled Case Series Study.

Cases of appendicitis were identified in the pivotal randomized clinical trial on BNT162b2 mRNA vaccine and reported from coronavirus disease 2019 (COVID-19) vaccine pharmacovigilance systems. Three cohort studies and two self-controlled case series (SCCS) studies evaluating the association between mRNA vaccines and appendicitis reported discordant results. To address this uncertainty, the present study examines in a large population, with a SCCS design, the association between mRNA (BNT162b2 and mRNA-1273) and, for the first time, viral vector (ChAdOx1-S and Ad26.COV2-S) COVID-19 vaccines and acute appendicitis. The SCCS study design was used to evaluate the association between COVID-19 vaccination and subsequent onset of acute appendicitis. The study was based on record linkage of health archives through TheShinISS application, a statistical tool that locally processes data from regional health care databases according to ad hoc, study-tailored and common data model. The study population included all vaccinated subjects ≥ 12 years old between 27 December 2020 and 30 September 2021. The acute appendicitis was identified through discharge diagnoses of hospital admissions or emergency department visits. Incident cases were defined as those who experienced a first event of acute appendicitis in the study period, excluding subjects with a diagnosis of appendicitis in the previous 5 years. Exposure was defined as the first or second dose of BNT162b2, mRNA-1273 and ChAdOx1-S and the single dose of Ad26.COV2-S. The risk interval was defined as 42 days from the first or second vaccination dose and divided into pre-specified risk subperiods; the reference period was the observation time outside the risk interval. Relative incidences (RI) and 95% confidence intervals (95% CI) were estimated with the SCCS method 'modified for event-dependent exposures', through unbiased estimating equations. The seasonal component was considered as a time-dependent covariate. In the 42-day risk interval 1285 incident cases of acute appendicitis occurred: 727 cases after the first dose and 558 cases after the second dose. In the main analysis, no increased risks of acute appendicitis were observed in subjects vaccinated with BNT162b, mRNA-1273, ChAdOx1-S and Ad26.COV2-S. The subgroup analyses by sex showed an increased risk in the 14-27 day risk interval, in males after the first dose of mRNA-1273 (RI of 1.71; 95% CI 1.08-2.70, p = 0.02) and in females after the single dose of Ad26.COV2-S (RI of 4.40; 95% CI 1.29-15.01, p = 0.02). There was no evidence of association of BNT162b, ChAdOx1-S, mRNA-1273 and Ad26.COV2-S with acute appendicitis in the general population. The results of the subgroup analyses by sex needs to be considered with caution. The multiplicity issue cannot be excluded being these hypotheses two of several hypotheses tested. In addition, relevant literature on the biological mechanism of the disease and evidence of similar effects with other vaccines or with the same vaccines are still lacking to provide strong support for a conclusion that there is an harmful effect in males and females with mRNA-1273 and Ad26.COV2-S.

P-056 NOA-SERA: combined autologous progenitor cells and platelet-derived growth factors for male factor infertility due to non-obstructive azoospermia and severe oligoasthenoteratozoospermia (OATS) – a case series

Abstract Study question Can NOA-SERA be utilizing autologous progenitor cells and platelet-derived growth factors,effectively address male factor infertility in non-obstructive azoospermia (NOA) and severeoligoasthenoteratozoospermia (OATS) Summary answer Intra-testicular NOA-SERA transplantation of autologous progenitor cells andgrowth factors shows promise in improving spermatogenesis and fertilization potential,presenting potential breakthrough for male factor infertility. What is known already Male infertility affects 10–15% of couples, with non-obstructive azoospermia (NOA)diagnosed in 60% of azoospermic men. Current interventions, including platelet-rich plasma and stem cells, show variable success. This study introduces a novel protocol, NOA-SERA, combining autologous mobilized progenitor cells and platelet-derived growth factors to restore spermatogenesis. Despite advancements in assisted reproduction, male factor infertility due to primary NOA remains challenging. This case series explores the safety and efficacy of NOA-SERA, avoiding in vitro breeding risks and emphasizing intratesticular transplantation’s safety and efficacy Study design, size, duration his case series (March 2019–November 2023) includes 7 male factor infertility patients,consisting of 4 non-obstructive azoospermic NOA, 1 cryptozoospermia and 2 severe oligoaesthenoteratospermic (OATS, strongly desirous of pregnancy with self-gamete. All patients received NOA-SERA following written consent. One-year follow-up included hormonal profiling, semen analysis, and testicular biopsy assessment Participants/materials, setting, methods Seven men, with normal karyotype, underwent NOA-SERA due to male factor infertility. This intervention involved intra-testicular transplantation of autologous CD34+/CD133+ enriched peripheral blood mononuclear stem cells (MPB-MNCs) combined with platelet derived growth factors. The procedure, avoiding in vitro breeding and manipulation, prioritized safety and efficacy. Follow-up for one year included hormonal profile, semen analysis, testicular biopsy assessments, clinical pregnancy (b-hCG), sustained implantation (>8 weeks), and live birth rates were followed. Main results and the role of chance Analysis of NOA-SERA treatment in this case series revealed positive outcomes in 70% of patients, showing increased testicular size, elevated testosterone, and reduced FSH levels. In our study, out of 4 NOA, 2 NOA remained NOA, 1 progressed to OATS, 1 progressed to normal semen analysis after 3 months. Couple conceived with intrauterine insemination (IUI) first pregnancy and they also had a subsequent natural conception. 1 Crypto progressed to OATS and 1 severe OATS remained the same and one progressed to OATS. Although no appearance of sperm in the ejaculate was observed, 2 patients displayed sperms in Testicular Sperm Aspiration (TESA) sufficient for ICSI. Couples undergoing IVF therapy post-biopsy achieved successful fertilization in two cases, leading to positive pregnancies and sustained implantation and livebirth of healthy full-term babies. Post-procedure FSH was slightly lower than pre-procedural levels, indicating hormonal improvement without observed therapy-related deterioration. The novelty lies in the intratesticular transplantation of mobilized purified autologous CD34+/CD133+ enriched MPBMNCs with platelet-derived growth factors, avoiding in vitro risks.” To summarise, 3 out of 7 achieved successful pregnancy, 2 NOA with ICSI, 1 NOA progressed to normal semen analysis and pregnancy with IUI Limitations, reasons for caution Despite interesting results, limitations include the self-controlled case series design and asmall patient cohort, lacking a comparison to a control group. Future studies should include more patients, stratified for age, aetiology, and other risk factors, to further elucidate this intervention’s mechanism of action Wider implications of the findings NOA-SERA demonstrates promise in enhancing spermatogenesis and fertilization potential, emphasizing necessity for larger randomized trials to ascertain clinical efficacy, particularly in subgroups of OATS&NOA patients. NOA-SERA emerges as safe, cost-effective adjuvant for optimizing spermatogenesis and improving IVF success and pregnancy outcomes in male factor infertility. Trial registration number Not applicable

Vacation in Egypt associated with Shiga toxin-producing Escherichia coli infection in children and adolescents, northern Italy, 2023.

BackgroundHaemolytic uremic syndrome (HUS) is a severe complication of infection with Shiga toxin-producing Escherichia coli (STEC). Although the reservoirs of STEC are known, the source of the infection of sporadic cases is often unknown. In 2023, we observed several cases of bloody diarrhoea with STEC infection in children and adolescents returning from vacations.AimWe aimed to explore the association between travel and bloody diarrhoea with STEC infection in children and adolescents.MethodsWe included all children and adolescents with bloody diarrhoea with STEC infection identified in 2023 by the ItalKid-HUS Network surveillance system in northern Italy. We interviewed children's families and sent a questionnaire on recent travels abroad. The exposure time was between 3 days after arrival abroad and 5 days after return home. A self-controlled case series (SCCS) design was used in the analysis.ResultsOf the 43 cases, 11 developed HUS. Twenty-three cases did not travel abroad, while 20 had travelled to several destinations. The incidence rate ratio (IRR) associated with travel to Egypt was 88.6 (95% confidence interval (CI): 17.0-462). Serotype analysis excluded the possibility of a single strain causing the infections. We did not find the source of the infections.ConclusionThere is an elevated risk of acquiring STEC infection with bloody diarrhoea and HUS associated with travel to Egypt. Specific investigations to identify the source are needed to implement effective preventive measures.

A Propensity Score Approach and a Partitioned Approach for the Self-Controlled Case Series Design to Evaluate Safety of a 2-dose Vaccine Series: Application to myocarditis/pericarditis following mRNA COVID-19 vaccination.

The assumption that serious adverse events (SAEs) do not affect subsequent exposure might not hold when evaluating 2-dose vaccine safety through a self-controlled case series (SCCS) design. To address this, we developed: 1) propensity score SCCS (PS-SCCS) using a propensity score model involving SAEs during the risk interval after dose 1 (${R}_1\Big)$, and 2) partitioned SCCS (P-SCCS) estimating relative incidence (RI) separately for doses 1 and 2. In simulations, both provided unbiased RIs. Conversely, standard SCCS overestimated RI after dose 2. We applied these approaches to assess myocarditis/pericarditis risks after 2-dose mRNA COVID-19 vaccination in 12-39-year-olds. For BNT162b2, PS-SCCS yielded RIs of 1.85 (95% CI, 0.75-4.59) and 11.05 (95% CI, 6.53-18.68) 14 days after doses 1 and 2 respectively; standard SCCS provided similar RI after dose 1 and RI of 12.92 (95% CI, 7.56-22.09) after dose 2. For mRNA-1273, standard SCCS showed RIs of 1.96 (95% CI, 0.56-6.91) after dose 1 and 7.87 (95% CI, 3.33-18.57) after dose 2. As no mRNA-1273 recipients with SAEs during ${R}_1$ received dose 2, P-SCCS was used, yielding similar RI after dose 1 and RI of 6.48 (95% CI, 2.83-14.83) after dose 2. mRNA vaccines were associated with elevated myocarditis/pericarditis risks following dose 2 in 12-39-year-olds.

Coronary and Cerebrovascular Events and Exacerbation of Existing Conditions After Laboratory‐Confirmed Influenza Infection Among US Veterans: A Self‐Controlled Case Series Study

ABSTRACTBackgroundInfluenza may contribute to coronary/cerebrovascular events and exacerbate underlying conditions.MethodsWe used self‐controlled case series (SCCS) design to analyze data from US Veterans ≥18 years with coronary/cerebrovascular or exacerbation event +/−1 year of lab‐confirmed influenza (LCI) during 2010–2018. We estimated the incidence ratio (IR) (95% CI) of the event for risk interval (Days 1–7 post‐LCI) versus control interval (all other times +/−1 year of LCI) with fixed‐effects conditional Poisson regression. We included biomarker data for mediation analysis.ResultsWe identified 3439 episodes with coronary/cerebrovascular‐related hospitalizations. IRs (95% CI) for LCI risk versus control interval were STEMI 0.6 (0.1, 4.4), NSTEMI 7.3 (5.8, 9.2), ischemic stroke 4.0 (3.0, 5.4), hemorrhagic stroke 6.2 (3.4, 11.5), and coronary spasm 1.3 (0.5, 3.0). IR significantly increased for NSTEMI and ischemic stroke among those ≥ 65 years. IR for NSTEMI and ischemic stroke dropped 26% and 10%, respectively, when white blood cell (WBC) and platelet count were considered. LCI was significantly associated with exacerbation of preexisting asthma, chronic obstructive pulmonary disease, and congestive heart failure.ConclusionsWe found significant association between LCI and hospitalization for NSTEMI, ischemic stroke, and hemorrhagic stroke, the latter possibly due to unaccounted time‐varying confounding in SCCS design.

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.

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.