Comparative Outcomes and Safety of Vedolizumab vs Tumor Necrosis Factor Antagonists for Older Adults With Inflammatory Bowel Diseases

IMPORTANCE: Observational comparative effectiveness studies can inform the positioning of biologic therapies for older patients with inflammatory bowel disease (IBD) who are underrepresented in clinical trials. OBJECTIVE: To compare the effectiveness and safety of vedolizumab vs tumor necrosis factor (TNF) for older patients with IBD. DESIGN, SETTING, AND PARTICIPANTS: This active comparator, new-user design, comparative effectiveness study was conducted between January 1, 2005, and December 31, 2018, among 754 older patients (aged ≥50 years) with IBD from the Danish National Patient Register. The mean follow-up after treatment initiation took place at 32 to 40 weeks. Statistical analysis was performed from February 1 to April 27, 2022. INTERVENTIONS: Treatment with vedolizumab or TNF antagonists. MAIN OUTCOMES AND MEASURES: The primary effectiveness outcome was treatment failure, defined as the composite risk of IBD-related hospitalization, IBD-related surgery, or a new corticosteroid prescription more than 6 weeks after initiation of treatment with biologic therapy. Secondary effectiveness outcomes were time to each individual component of the composite effectiveness outcome. The primary safety outcome was the risk of serious infections, defined as infections requiring hospitalization. A 1:1 propensity score–matched analysis was conducted, accounting for patient-, disease-, and treatment-associated factors. RESULTS: The study compared 377 older patients with IBD with incident use of vedolizumab (202 women [53.6%]; mean [SD] age, 61.2 [8.3] years; 177 [46.9%] with Crohn disease) vs 377 patients with incident use of TNF antagonists (206 women [54.6%]; mean [SD] age, 61.3 [8.1] years; 182 [48.3%] with Crohn disease). Overall, vedolizumab was associated with an increased risk of treatment failure compared with TNF antagonists (1-year risk, 45.4% vs 34.7%; adjusted hazard ratio [HR], 1.31; 95% CI, 1.02-1.69), including higher risk of IBD-related hospitalization (1-year risk, 27.8% vs 16.3%; adjusted HR, 1.48; 95% CI, 1.03-2.15) and IBD-related major abdominal surgery (1-year risk, 21.3% vs 8.0%; adjusted HR, 2.39; 95% CI, 1.45-3.94). In subgroup analysis by IBD phenotype, among patients with Crohn disease, vedolizumab was associated with a 77% higher risk of treatment failure (adjusted HR, 1.77; 95% CI, 1.21-2.58), while no difference in risk of treatment failure was seen among patients with ulcerative colitis (adjusted HR, 1.04; 95% CI, 0.75-1.43; P = .03 for interaction). There was no significant difference in the risk of serious infections, overall (1-year risk, 8.2% vs 8.7%; adjusted HR, 1.04; 95% CI, 0.58-1.85) and by IBD phenotype. CONCLUSIONS AND RELEVANCE: In this comparative effectiveness study of older patients with IBD, vedolizumab was associated with a higher risk of treatment failure compared with TNF antagonists, particularly among patients with Crohn disease, without offering a significant safety advantage

Waiting time distribution in public health care: empirics and theory

Excessive waiting times for elective surgery have been a long-standing concern in many national healthcare systems in the OECD. How do the hospital admission patterns that generate waiting lists affect different patients? What are the hospitals characteristics that determine waiting times? By developing a model of healthcare provision and analysing empirically the entire waiting time distribution we attempt to shed some light on those issues. We first build a theoretical model that describes the optimal waiting time distribution for capacity constraint hospitals. Secondly, employing duration analysis, we obtain empirical representations of that distribution across hospitals in the UK from 1997–2005. We observe important differences on the ‘scale’ and on the ‘shape’ of admission rates. Scale refers to how quickly patients are treated and shape represents trade-offs across duration-treatment profiles. By fitting the theoretical to the empirical distributions we estimate the main structural parameters of the model and are able to closely identify the main drivers of these empirical differences. We find that the level of resources allocated to elective surgery (budget and physical capacity), which determines how constrained the hospital is, explains differences in scale. Changes in benefits and costs structures of healthcare provision, which relate, respectively, to the desire to prioritise patients by duration and the reduction in costs due to delayed treatment, determine the shape, affecting short and long duration patients differently

Development of Inflammatory Bowel Disease in HIV Patients:A Danish Cohort Study (1983-2018) With American Validation (1999-2018)

BACKGROUND AND AIMS: Human immunodeficiency virus (HIV) infection is associated with several immune-mediated disorders. However, the risk of inflammatory bowel disease (IBD) in people living with HIV (PLWH) remains unclear. We aimed to assess the risk of IBD among PLWH using a nationwide, population-based Danish cohort and to validate findings in a large American insurance-based database. METHODS: Using Danish registries (1983–2018), we identified 8995 PLWH and age- and sex-matched them to 449,750 HIV-negative individuals. Cox regression analysis was undertaken to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for IBD diagnosis. Results were stratified by sex, age, and year of HIV diagnosis. Using an American insurance-based cohort, Explorys (1999–2018), we assessed the prevalence odds ratio (OR) and 95% CI of IBD diagnosis in PLWH compared with HIV-negative individuals. RESULTS: IBD diagnosis among PLWH in Denmark was increased (HR: 2.25, 95% CI: 1.78–2.83) compared with matched HIV-negative individuals. This was seen for both Crohn’s disease (HR: 2.25, 95% CI: 1.47–3.44) and ulcerative colitis (HR: 2.24, 95% CI: 1.70–2.96) and in male (HR: 2.75, 95% CI: 2.15–3.52) but not female (HR: 0.93, 95% CI: 0.48–1.79) PLWH. Explorys analysis also showed an increased odds of IBD diagnoses among PLWH (OR: 1.41; 95% CI: 1.35–1.49). CONCLUSION: This study finds an increased risk of IBD diagnosis among PLWH in both a Danish and US cohort, highlighting a need to consider IBD in PLWH with new-onset gastrointestinal symptoms. Further research into the role of antiretroviral therapy in this relationship is required

Risk factors of visceral leishmaniasis in East Africa: a case-control study in Pokot territory of Kenya and Uganda

BACKGROUND: In East Africa, visceral leishmaniasis (VL) is endemic in parts of Sudan, Ethiopia, Somalia, Kenya and Uganda. It is caused by Leishmania donovani and transmitted by the sandfly vector Phlebotomus martini. In the Pokot focus, reaching from western Kenya into eastern Uganda, formulation of a prevention strategy has been hindered by the lack of knowledge on VL risk factors as well as by lack of support from health sector donors. The present study was conducted to establish the necessary evidence-base and to stimulate interest in supporting the control of this neglected tropical disease in Uganda and Kenya. METHODS: A case-control study was carried out from June to December 2006. Cases were recruited at Amudat hospital, Nakapiripirit district, Uganda, after clinical and parasitological confirmation of symptomatic VL infection. Controls were individuals that tested negative using a rK39 antigen-based dipstick, which were recruited at random from the same communities as the cases. Data were analysed using conditional logistic regression. RESULTS: Ninety-three cases and 226 controls were recruited into the study. Multivariate analysis identified low socio-economic status and treating livestock with insecticide as risk factors for VL. Sleeping near animals, owning a mosquito net and knowing about VL symptoms were associated with a reduced risk of VL. CONCLUSIONS: VL affects the poorest of the poor of the Pokot tribe. Distribution of insecticide-treated mosquito nets combined with dissemination of culturally appropriate behaviour-change education is likely to be an effective prevention strategy

Rapid evolution of virulence and drug resistance in the emerging zoonotic pathogen Streptococcus suis

Background: Streptococcus suis is a zoonotic pathogen that infects pigs and can occasionally cause serious infections in humans. S. suis infections occur sporadically in human Europe and North America, but a recent major outbreak has been described in China with high levels of mortality. The mechanisms of S. suis pathogenesis in humans and pigs are poorly understood. Methodology/Principal Findings: The sequencing of whole genomes of S. suis isolates provides opportunities to investigate the genetic basis of infection. Here we describe whole genome sequences of three S. suis strains from the same lineage: one from European pigs, and two from human cases from China and Vietnam. Comparative genomic analysis was used to investigate the variability of these strains. S. suis is phylogenetically distinct from other Streptococcus species for which genome sequences are currently available. Accordingly, ,40% of the ,2 Mb genome is unique in comparison to other Streptococcus species. Finer genomic comparisons within the species showed a high level of sequence conservation; virtually all of the genome is common to the S. suis strains. The only exceptions are three ,90 kb regions, present in the two isolates from humans, composed of integrative conjugative elements and transposons. Carried in these regions are coding sequences associated with drug resistance. In addition, small-scale sequence variation has generated pseudogenes in putative virulence and colonization factors. Conclusions/Significance: The genomic inventories of genetically related S. suis strains, isolated from distinct hosts and diseases, exhibit high levels of conservation. However, the genomes provide evidence that horizontal gene transfer has contributed to the evolution of drug resistance

Fractional two-branes, toric orbifolds and the quantum McKay correspondence

We systematically study and obtain the large-volume analogues of fractional two-branes on resolutions of orbifolds C^3/Z_n. We study a generalisation of the McKay correspondence proposed in hep-th/0504164 called the quantum McKay correspondence by constructing duals to the fractional two-branes. Details are explicitly worked out for two examples -- the crepant resolutions of C^3/Z_3 and C^3/Z_5.Comment: 34 pages, 2 figures, LaTeX (JHEP3 style); (v2) typos corrected; (v3) sec 3 reorganise

Analysis and quantification of the diversities of aerosol life cycles within AeroCom

Simulation results of global aerosol models have been assembled in the framework of the AeroCom intercomparison exercise. In this paper, we analyze the life cycles of dust, sea salt, sulfate, black carbon and particulate organic matter as simulated by sixteen global aerosol models. The diversities among the models for the sources and sinks, burdens, particle sizes, water uptakes, and spatial dispersals have been established. These diversities have large consequences for the calculated radiative forcing and the aerosol concentrations at the surface. The AeroCom all-models-average emissions are dominated by the mass of sea salt (SS), followed by dust (DU), sulfate (SO_4), particulate organic matter (POM), and finally black carbon (BC). Interactive parameterizations of the emissions and contrasting particles sizes of SS and DU lead generally to higher diversities of these species, and for total aerosol. The lower diversity of the emissions of the fine aerosols, BC, POM, and SO_4, is due to the use of similar emission inventories, and does therefore not necessarily indicate a better understanding of their sources. The diversity of SO_4-sources is mainly caused by the disagreement on depositional loss of precursor gases and on chemical production. The diversities of the emissions are passed on to the burdens, but the latter are also strongly affected by the model-specific treatments of transport and aerosol processes. The burdens of dry masses decrease from largest to smallest: DU, SS, SO_4, POM, and BC. The all-models-average residence time is shortest for SS with about half a day, followed by S_O4 and DU with four days, and POM and BC with six and seven days, respectively. The wet deposition rate is controlled by the solubility and increases from DU, BC, POM to SO_4 and SS. It is the dominant sink for SO_4, BC, and POM, and contributes about one third to the total removal rate coefficients of SS and DU species. For SS and DU we find high diversities for the removal rate coefficients and deposition pathways. Models do neither agree on the split between wet and dry deposition, nor on that between sedimentation and turbulent dry Deposition. We diagnose an extremely high diversity for the uptake of ambient water vapor that influences the particle size and thus the sink rate coefficients. Furthermore, we find little agreement among the model results for the partitioning of wet removal into scavenging by convective and stratiform rain. Large differences exist for aerosol dispersal both in the vertical and in the horizontal direction. In some models, a minimum of total aerosol concentration is simulated at the surface. Aerosol dispersal is most pronounced for SO4 and BC and lowest for SS. Diversities are higher for meridional than for vertical dispersal, they are similar for a given species and highest for SS and DU. For these two components we do not find a correlation between vertical and meridional aerosol dispersal. In addition the degree of dispersals of SS and DU is not related to their residence times. SO_4, BC, and POM, however, show increased meridional dispersal in models with larger vertical dispersal, and dispersal is larger for longer simulated residence times