Carbon budget at the individual-tree scale: dominant Eucalyptus trees partition less carbon belowground.

Large trees in plantations generally produce more wood per unit of resource use than small trees. Two processes may account for this pattern: greater photosynthetic resource use efficiency or greater partitioning of carbon to wood production. We estimated gross primary production (GPP) at the individual scale by combining transpiration with photosynthetic water-use efficiency of Eucalyptus trees. Aboveground production fluxes were estimated using allometric equations and modeled respiration; total belowground carbon fluxes (TBCF) were estimated by subtracting aboveground fluxes from GPP. Partitioning was estimated by dividing component fluxes by GPP. Dominant trees produced almost three times as much wood as suppressed trees. They used 25 ± 10% (mean ± SD) of their photosynthates for wood production, whereas suppressed trees only used 12 ± 2%. By contrast, dominant trees used 27 ± 19% of their photosynthate belowground, whereas suppressed trees used 58 ± 5%. Intermediate trees lay between these extremes. Photosynthetic water-use efficiency of dominant trees was c. 13% greater than the efficiency of suppressed trees. Suppressed trees used more than twice as much of their photosynthate belowground and less than half as much aboveground compared with dominant trees. Differences in carbon partitioning were much greater than differences in GPP or photosynthetic water-use efficiency.

Conceptual risk assessment of mosquito population modification gene-drive systems to control malaria transmission: preliminary hazards list workshops.

The field-testing and eventual adoption of genetically-engineered mosquitoes (GEMs) to control vector-borne pathogen transmission will require them meeting safety criteria specified by regulatory authorities in regions where the technology is being considered for use and other locales that might be impacted. Preliminary risk considerations by researchers and developers may be useful for planning the baseline data collection and field research used to address the anticipated safety concerns. Part of this process is to identify potential hazards (defined as the inherent ability of an entity to cause harm) and their harms, and then chart the pathways to harm and evaluate their probability as part of a risk assessment. The University of California Malaria Initiative (UCMI) participated in a series of workshops held to identify potential hazards specific to mosquito population modification strains carrying gene-drive systems coupled to anti-parasite effector genes and their use in a hypothetical island field trial. The hazards identified were placed within the broader context of previous efforts discussed in the scientific literature. Five risk areas were considered i) pathogens, infections and diseases, and the impacts of GEMs on human and animal health, ii) invasiveness and persistence of GEMs, and interactions of GEMs with target organisms, iii) interactions of GEMs with non-target organisms including horizontal gene transfer, iv) impacts of techniques used for the management of GEMs and v) evolutionary and stability considerations. A preliminary hazards list (PHL) was developed and is made available here. This PHL is useful for internal project risk evaluation and is available to regulators at prospective field sites. UCMI project scientists affirm that the subsequent processes associated with the comprehensive risk assessment for the application of this technology should be driven by the stakeholders at the proposed field site and areas that could be affected by this intervention strategy.

Assessment of venous pressure by compression sonography of the internal jugular vein during 3 days of bed rest.

Compression sonography has been proposed as a method for non-invasive measurement of venous pressures during spaceflight, but initial reports of venous pressure measured by compression ultrasound conflict with prior reports of invasively measured central venous pressure (CVP). The aim of this study is to determine the agreement of compression sonography of the internal jugular vein (IJVP) with invasive measures of CVP over a range of pressures relevant to microgravity exposure. Ten healthy volunteers (18-55 years, five female) completed two 3-day sessions of supine bed rest to simulate microgravity. IJVP and CVP were measured in the seated position, and in the supine position throughout 3 days of bed rest. The range of CVP recorded was in line with previous reports of CVP during changes in posture on Earth and in microgravity. The correlation between IJVP and CVP was poor when measured during spontaneous breathing (r = 0.29; R2  = 0.09; P = 0.0002; standard error of the estimate (SEE) = 3.0 mmHg) or end-expiration CVP (CVPEE ; r = 0.19; R2  = 0.04; P = 0.121; SEE = 3.0 mmHg). There was a modest correlation between the change in CVP and the change in IJVP for both spontaneous ΔCVP (r = 0.49; R2  = 0.24; P < 0.0001) and ΔCVPEE (r = 0.58; R2  = 0.34; P < 0.0001). Bland-Altman analysis of IJVP revealed a large positive bias compared to spontaneous breathing CVP (3.6 mmHg; SD = 4.0; CV = 85%; P < 0.0001) and CVPEE (3.6 mmHg; SD = 4.2; CV = 84%; P < 0.0001). Assessment of absolute IJVP via compression sonography correlated poorly with direct measurements of CVP by invasive catheterization over a range of venous pressures that are physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time. NEW FINDINGS: What is the central question of this study? Compression sonography has been proposed as a novel method for non-invasive measurement of venous pressures during spaceflight. However, the accuracy has not yet been confirmed in the range of CVP experienced by astronauts during spaceflight. What is the main finding and its importance? Our data show that compression sonography of the internal jugular vein correlates poorly with direct measurement of central venous pressures in a range that is physiologically relevant to spaceflight. However, compression sonography showed modest utility for tracking changes in venous pressure over time.

New Terminology and Methodology for the Assessment of the Vitreous, Its Floaters and Opacities, and Their Effect on Vision: Standardized and Kinetic Anatomical and Functional Testing of Vitreous Floaters and Opacities (SK VFO Test).

OBJECTIVE: To introduce VFO and SK VFO Test: new, more representative terminology for symptoms of vitreous floaters/opacities (VFO) and new standardized kinetic (SK) anatomical-functional assessment. MATERIALS AND METHODS: Eight eyes underwent before-after limited vitrectomy (LV): best-corrected visual acuity, low-luminance visual acuity, Minnesota Low Vision Reading Chart near visual acuity in logMAR, contrast sensitivity function (CV1000E), and straylight measurements (SM) (HDA/LDA/C-Quant). SK infrared confocal scanning laser ophthalmoscopy (SK IRcSLO) and swept-source widefield optical coherence tomography (SS-WF-OCT) identified VFO and posterior vitreous detachment (PVD). SK IRcSLO was performed with gaze directed towards the extreme superior, inferior, and lateral directions. RESULTS: Anatomical-functional results after LV improved in 7 eyes (87.5%): objective scatter index (27.34%), disturbance index (47.97%) and C-Quant Log units (2.26%). Pre-LV SK IRcSLO and SS-WFOCT imaging identified dynamic well-defined VFO and PVD status (100%). A residual asymptomatic anterior cortical vitreous-induced shadowing ripple effect was detected post-LV. CONCLUSIONS: This is the first objective-standardized test accounting for VFO kinesis and intermittent effect. There is potential for personalizing treatment and establishing best candidates for laser or surgery. [Ophthalmic Surg Lasers Imaging Retina 2023;54:306-315.].

Components explain, but do eddy fluxes constrain? Carbon budget of a nitrogen-fertilized boreal Scots pine forest.

Nitrogen (N) fertilization increases biomass and soil organic carbon (SOC) accumulation in boreal pine forests, but the underlying mechanisms remain uncertain. At two Scots pine sites, one undergoing annual N fertilization and the other a reference, we sought to explain these responses. We measured component fluxes, including biomass production, SOC accumulation, and respiration, and summed them into carbon budgets. We compared the resulting summations to ecosystem fluxes measured by eddy covariance. N fertilization increased most component fluxes (P < 0.05), especially SOC accumulation (20×). Only fine-root, mycorrhiza, and exudate production decreased, by 237 (SD = 28) g C m-2 yr-1 . Stemwood production increases were ascribed to this partitioning shift, gross primary production (GPP), and carbon-use efficiency, in that order. The methods agreed in their estimates of GPP in both stands (P > 0.05), but the components detected an increase in net ecosystem production (NEP) (190 (54) g C m-2 yr-1 ; P < 0.01) that eddy covariance did not (19 (62) g C m-2 yr-1 ; ns). The pairing of plots, the simplicity of the sites, and the strength of response provide a compelling description of N effects on the C budget. However, the disagreement between methods calls for further paired tests of N fertilization effects in simple forest ecosystems.

Ulcer Size After Induction Therapy Performs Better Than Symptom Assessment for Prediction of One Year Endoscopic Remission in Crohn's Disease: A Post Hoc Analysis.

BACKGROUND: We evaluated whether postinduction ulcer size and patient-reported outcome (PRO) severity are associated with the achievement of 1-year endoscopic remission (ER) in patients with Crohn's disease (CD). METHODS: This post hoc analysis combined data from several clinical trials including 283 patients with baseline ulcers ≥5 mm with repeat endoscopy after ustekinumab or adalimumab induction therapy. Patient-reported outcomes including stool frequency (SF) and abdominal pain (AP) were measured by the Crohn's Disease Activity Index. Thresholds of SF ≥4 and/or AP ≥2 indicated moderately to severely active CD. Endoscopic remission was defined as Simple Endoscopic Score for CD (SES-CD) <3. Multivariate logistic regression models adjusted for confounders (including disease duration and treatment allocation) evaluated the relationships between postinduction ulcer size, PRO symptoms, and achievement of 1-year ER. RESULTS: Among the 131 CD patients who continued to have ulcers ≥5 mm after induction therapy, 48 (36.6%) achieved 1-year ER. Patients with postinduction ulcers ≥5 mm were approximately 5 times less likely to achieve 1-year ER than the 152 individuals who had small or no postinduction ulcers (odds ratio [OR], 0.20; 95% CI, 0.08-0.51, P = .001). In patients with ulcers ≥5 mm after induction, postinduction PRO scores (including PRO2 and PRO3) did not predict 1-year ER. CONCLUSIONS: Crohn's disease patients with ulcers ≥5 mm after induction therapy are less likely to achieve 1-year ER. Postinduction PRO severity does not offer additional prognostic information. This may suggest that objective measures of disease such as endoscopic ulcer size should be considered over symptom assessments for determining clinical response to therapy and utilized in trials for maintenance therapy.

Crohn's disease patients with ulcers ≥5 mm after induction therapy are less likely to achieve 1-year endoscopic remission. Postinduction patient-reported symptom severity does not offer additional prognostic information. Objective measures of disease such as endoscopic ulcer size should be considered over symptom assessments for determining clinical response to therapy.

The impact of ultrasound-based antenatal screening strategies to detect vasa praevia in the United Kingdom: An exploratory study using decision analytic modelling methods.

The objective of this exploratory modelling study was to estimate the effects of second-trimester, ultrasound-based antenatal detection strategies for vasa praevia (VP) in a hypothetical cohort of pregnant women. For this, a decision-analytic tree model was developed covering four discrete detection pathways/strategies: no screening; screening targeted at women undergoing in-vitro fertilisation (IVF); screening targeted at women with low-lying placentas (LLP); screening targeted at women with velamentous cord insertion (VCI) or a bilobed or succenturiate (BL/S) placenta. Main outcome measures were the number of referrals to transvaginal sonography (TVS), diagnosed and undiagnosed cases of VP, overdetected cases of VCI, and VP-associated perinatal mortality. The greatest number of referrals to TVS occurred in the LLP-based (2,083) and VCI-based screening (1,319) pathways. These two pathways also led to the highest proportions of pregnancies diagnosed with VP (VCI-based screening: 552 [78.9% of all pregnancies]; LLP-based: 371 [53.5%]) and the lowest proportions of VP leading to perinatal death (VCI-based screening: 100 [14.2%]; LLP-based: 196 [28.0%]). In contrast, the IVF-based pathway resulted in 66 TVS referrals, 50 VP diagnoses (7.1% of all VP pregnancies), and 368 (52.6%) VP-associated perinatal deaths which was comparable to the no screening pathway (380 [54.3%]). The VCI-based pathway resulted in the greatest detection of VCI (14,238 [99.1%]), followed by the IVF-based pathway (443 [3.1%]); no VCI detection occurred in the LLP-based or no screening pathways. In conclusion, the model results suggest that a targeted LLP-based approach could detect a substantial proportion of VP cases, while avoiding VCI overdetection and requiring minimal changes to current clinical practice. High-quality data is required to explore the clinical and cost-effectiveness of this and other detection strategies further. This is necessary to provide a robust basis for future discussion about routine screening for VP.

Health economic evaluation alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (E-PROSPECT): a cost-effectiveness analysis.

PURPOSE: We sought to compare the cost-effectiveness of probiotics and usual care with usual care without probiotics in mechanically ventilated, intensive care unit patients alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (PROSPECT). METHODS: We conducted a health economic evaluation alongside the PROSPECT randomized control trial (October 2013-March 2019). We adopted a public healthcare payer's perspective. Forty-four intensive care units in three countries (Canada/USA/Saudi Arabia) with adult critically ill, mechanically ventilated patients (N = 2,650) were included. Interventions were probiotics (Lactobacillus rhamnosus GG) vs placebo administered enterally twice daily. We collected healthcare resource use and estimated unit costs in 2019 United States dollars (USD) over a time horizon from randomization to hospital discharge/death. We calculated incremental cost-effectiveness ratios (ICERs) comparing probiotics vs usual care. The primary outcome was incremental cost per ventilator-associated pneumonia (VAP) event averted; secondary outcomes were costs per Clostridioides difficile-associated diarrhea (CDAD), antibiotic-associated diarrhea (AAD), and mortality averted. Uncertainty was investigated using nonparametric bootstrapping and sensitivity analyses. RESULTS: Mean (standard deviation [SD]) cost per patient was USD 66,914 (91,098) for patients randomized to probiotics, with a median [interquartile range (IQR)] of USD 42,947 [22,239 to 76,205]. By comparison, for those not receiving probiotics, mean (SD) cost per patient was USD 62,701 (78,676) (median [IQR], USD 41,102 [23,170 to 75,140]; incremental cost, USD 4,213; 95% confidence interval [CI], -2,269 to 10,708). Incremental cost-effectiveness ratios for VAP or AAD events averted, probiotics were dominated by usual care (more expensive, with similar effectiveness). The ICERs were USD 1,473,400 per CDAD event averted (95% CI, undefined) and USD 396,764 per death averted (95% CI, undefined). Cost-effectiveness acceptability curves reveal that probiotics were not cost-effective across wide ranges of plausible willingness-to-pay thresholds. Sensitivity analyses did not change the conclusions. CONCLUSIONS: Probiotics for VAP prevention among critically ill patients were not cost-effective. Study registration data www. CLINICALTRIALS: gov (NCT01782755); registered 4 February 2013.

RéSUMé: OBJECTIF: Nous avons cherché à comparer le rapport coût-efficacité d'un traitement avec probiotiques ajoutés aux soins habituels avec des soins habituels prodigués sans probiotiques chez les patients des soins intensifs sous ventilation mécanique dans le cadre de l'étude PROSPECT (Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial). MéTHODE: Nous avons réalisé une évaluation de l'économie de la santé parallèlement à l'étude randomisée contrôlée PROSPECT (octobre 2013-mars 2019). Nous avons adopté le point de vue d'un payeur public de services de santé. Quarante-quatre unités de soins intensifs dans trois pays (Canada/États-Unis/Arabie saoudite) prenant soin de patients adultes gravement malades sous ventilation mécanique (n = 2650) ont été inclus. Les interventions ont été les suivantes : probiotiques (Lactobacillus rhamnosus GG) vs placebo administrés par voie entérale deux fois par jour. Nous avons recueilli les données concernant l'utilisation des ressources en soins de santé et estimé les coûts unitaires en dollars américains (USD) de 2019 sur un horizon temporel allant de la randomisation au congé de l'hôpital / décès. Nous avons calculé des rapports coût-efficacité différentiels (RCED) en comparant les probiotiques vs les soins habituels. Le critère d'évaluation principal était le coût différentiel par événement évité de pneumonie associée au ventilateur (PAV); les critères d'évaluation secondaires étaient les coûts par diarrhée associée au Clostridioides difficile (DACD), diarrhée associée aux antibiotiques (DAA) et mortalité évitées. L'incertitude a été étudiée à l'aide d'analyses d'amorçage et de sensibilité non paramétriques. RéSULTATS: Le coût moyen (écart type [ÉT]) par patient était de 66 914 (91 098) USD pour les patients randomisés au groupe probiotiques, avec une médiane [écart interquartile (ÉIQ)] de 42 947 USD [22 239 à 76 205]. En comparaison, pour ceux ne recevant pas de probiotiques, le coût moyen (ÉT) par patient était de 62 701 USD (78 676) (médiane [ÉIQ], 41 102 USD [23 170 à 75 140]; coût différentiel, 4213 USD; intervalle de confiance [IC] à 95%, -2269 à 10 708). En matière de rapports coût-efficacité différentiels pour les événements de PAV ou DAA évités, les probiotiques étaient dominés par les soins habituels (plus coûteux, avec une efficacité similaire). Les RCED étaient de 1 473 400 USD par événement de DACD évitée (IC 95 %, non défini) et de 396 764 USD par décès évité (IC 95 %, non défini). Les courbes d'acceptabilité coût-efficacité révèlent que les probiotiques n'étaient pas rentables dans de larges gammes de seuils plausibles de volonté de payer. Les analyses de sensibilité n'ont pas modifié les conclusions. CONCLUSION: Les probiotiques utilisés pour prévenir la PAV chez les patients gravement malades n'étaient pas rentables. Enregistrement de l'étude : www.clinicaltrials.gov (NCT01782755); enregistrée le 4 février 2013.

Recommendations for environmental risk assessment of gene drive applications for malaria vector control.

Building on an exercise that identified potential harms from simulated investigational releases of a population suppression gene drive for malaria vector control, a series of online workshops identified nine recommendations to advance future environmental risk assessment of gene drive applications.

Cost Effectiveness of Subcutaneous Vedolizumab for Maintenance Treatment of Ulcerative Colitis in Canada.

BACKGROUND AND OBJECTIVES: Ulcerative colitis is highly prevalent in Canada and cost-effective ulcerative colitis therapies are warranted. Vedolizumab subcutaneous (SC) formulation was recently approved for ulcerative colitis maintenance therapy. We assessed vedolizumab SC cost effectiveness vs conventional and advanced therapeutics in patients with moderately to severely active ulcerative colitis from a Canadian public healthcare payer perspective. METHODS: A hybrid decision tree/Markov model was developed to evaluate vedolizumab SC costs, quality-adjusted life-years, and cost effectiveness vs conventional therapy, adalimumab SC, infliximab intravenous, golimumab SC, tofacitinib, ustekinumab SC, and vedolizumab intravenous. This model predicts the number of patients achieving clinical response and remission after treatment induction, and sustained benefit during maintenance treatment. To account for statistical uncertainties, the base-case analysis was conducted in a probabilistic manner. Scenario analyses examined the impact of previous treatment with anti-tumor necrosis factor agents, dose escalation, loss of efficacy, and treatment adherence. RESULTS: In the base-case analysis, conventional therapy was the most cost-effective therapeutic option in the overall population. Vedolizumab SC was cost effective and dominant compared with other advanced therapies (adalimumab, golimumab, infliximab, tofacitinib 5 mg, ustekinumab, and vedolizumab intravenous). The annual vedolizumab SC cost per patient was reduced vs ustekinumab SC, tofacitinib 5 mg, vedolizumab intravenous, and golimumab SC by $47,024, $3251, $2120, and $2004 (Canadian dollars), respectively, and exceeded that of infliximab, adalimumab, and conventional therapy by $582, $3293, and $41,024, respectively. Among the treatments, vedolizumab SC generated the highest quality-adjusted life-years overall (14.21), which translated into the best incremental cost per quality-adjusted life-years gained over conventional therapy in the overall population ($109,374) and in anti-tumor necrosis factor-naïve and anti-tumor necrosis factor-experienced patients ($41,658/$114,287). CONCLUSIONS: Conventional therapy offered the most cost-effective therapeutic option followed by vedolizumab SC. Based on a $50,000/quality-adjusted life-year threshold, vedolizumab was cost effective in anti-tumor necrosis factor-naïve patients but not the overall population also when compared to conventional therapy.

Fecal Microbiota Transplantation for the Treatment of Ulcerative Colitis: A Qualitative Assessment of Patient Perceptions and Experiences.

BACKGROUND: Fecal microbiota transplantation (FMT) is a promising experimental therapy for ulcerative colitis (UC), yet patient acceptance remains poorly understood. AIMS: The aim of this study was to explore perceptions and experiences of adult patients who received FMT for UC. METHODS: This study used a qualitative descriptive design with thematic content analysis. Patients who were approached for enrollment in a clinical trial (NCT02606032) were invited to participate in face-to-face semistructured interviews. Two groups were interviewed: those who chose to pursue FMT and those who declined FMT. Non-FMT patients were interviewed once; FMT patients were interviewed twice at pre- and post-treatment. RESULTS: Nine FMT patients (78% female, average age 46.7 years old) and eight non-FMT patients (50% female, average age 39.5 years old) were enrolled. Pretreatment themes included FMT as a natural therapy, external barriers to pursuing FMT, concerns with FMT and factors influencing the decision to pursue FMT. While both groups generally perceived FMT as a natural therapy, pre-FMT patients showed greater acceptance of alternative medicine. Both groups demonstrated poor understanding and similar initial concerns with product cleanliness. Pre-FMT patients were motivated to pursue FMT by feelings of last resort. Post-FMT themes included therapeutic impact of FMT and psychosocial impact of FMT. Post-FMT patients reported overall satisfaction and a unanimous preference for FMT over conventional medications. CONCLUSION: This is the first study to assess adult patient perceptions and real-life experiences with FMT for the treatment of UC. By improving patient education, we may achieve greater acceptance of FMT.

White Paper on Early Critical Care Services in Low Resource Settings.

This White Paper has been formally accepted for support by the International Federation for Emergency Medicine (IFEM) and by the World Federation of Intensive and Critical Care (WFICC), put forth by a multi-specialty group of intensivists and emergency medicine providers from low- and low-middle-income countries (LMICs) and high-income countries (HiCs) with the aim of 1) defining the current state of caring for the critically ill in low-resource settings (LRS) within LMICs and 2) highlighting policy options and recommendations for improving the system-level delivery of early critical care services in LRS. LMICs have a high burden of critical illness and worse patient outcomes than HICs, hence, the focus of this White Paper is on the care of critically ill patients in the early stages of presentation in LMIC settings. In such settings, the provision of early critical care is challenged by a fragmented health system, costs, a health care workforce with limited training, and competing healthcare priorities. Early critical care services are defined as the early interventions that support vital organ function during the initial care provided to the critically ill patient-these interventions can be performed at any point of patient contact and can be delivered across diverse settings in the healthcare system and do not necessitate specialty personnel. Currently, a single "best" care delivery model likely does not exist in LMICs given the heterogeneity in local context; therefore, objective comparisons of quality, efficiency, and cost-effectiveness between varying models are difficult to establish. While limited, there is data to suggest that caring for the critically ill may be cost effective in LMICs, contrary to a widely held belief. Drawing from locally available resources and context, strengthening early critical care services in LRS will require a multi-faceted approach, including three core pillars: education, research, and policy. Education initiatives for physicians, nurses, and allied health staff that focus on protocolized emergency response training can bridge the workforce gap in the short-term; however, each country's current human resources must be evaluated to decide on the duration of training, who should be trained, and using what curriculum. Understanding the burden of critical Illness, best practices for resuscitation, and appropriate quality metrics for different early critical care services implementation models in LMICs are reliant upon strengthening the regional research capacity, therefore, standard documentation systems should be implemented to allow for registry use and quality improvement. Policy efforts at a local, national and international level to strengthen early critical care services should focus on funding the building blocks of early critical care services systems and promoting the right to access early critical care regardless of the patient's geographic or financial barriers. Additionally, national and local policies describing ethical dilemmas involving the withdrawal of life-sustaining care should be developed with broad stakeholder representation based on local cultural beliefs as well as the optimization of limited resources.

A Cost-Utility Analysis of Switching from Reference to Biosimilar Infliximab Compared to Maintaining Reference Infliximab in Adult Patients with Crohn's Disease.

BACKGROUND AND AIMS: Lower-cost biosimilar infliximab may address affordability concerns in the treatment of adults with Crohn's disease (CD), however, evidence regarding the cost-effectiveness of switching from reference to biosimilar is warranted. The aim of this research was to assess the incremental cost of switching from treatment with reference infliximab to biosimilar compared with maintaining reference infliximab in adults with CD per quality-adjusted life year (QALY) gained. METHODS: A probabilistic cohort Markov model with 8-week cycle lengths was constructed to estimate the incremental costs and effects of switching over a 5-year time horizon from a public payer perspective. Base-case clinical inputs were obtained from NOR-SWITCH subgroup analyses and other published trials. Costs were obtained from Canadian sources. A total of 10,000 simulations were run. Sensitivity analysis was used to test the robustness of the results to variations in uncertain parameters. RESULTS: Switching to biosimilar infliximab was less costly but also less effective with incremental savings of $46,194 (95% confidence interval [CI]: $42,420, $50,455) and a loss in QALYs of -0.13 (95% CI: -0.16, -0.07). Eighty-three per cent of the simulations demonstrated incremental cost savings and an incremental loss of effectiveness. The model was sensitive to differences in rates of disease worsening between reference and biosimilar infliximab. CONCLUSIONS: While biosimilar infliximab is associated with incremental savings for patients on maintenance therapy who are switched from reference infliximab, funding decision makers must decide whether a small loss of effectiveness is justified. Further evidence will help to inform reimbursement policy.

Evaluating the Cost-Effectiveness of Changes to the Surveillance Intervals in the UK Abdominal Aortic Aneurysm Screening Programme.

OBJECTIVES: To investigate the safety and cost-effectiveness of lengthening the time between surveillance ultrasound scans in the UK Abdominal Aortic Aneurysm (AAA) Screening Programme. METHODS: A discrete event simulation model was used to evaluate the cost-effectiveness of AAA screening for men aged 65, comparing current surveillance intervals to 6 alternative surveillance interval strategies that lengthened the time between surveillance scans for 1 or more AAA size categories. The model considered clinical events and costs incurred over a 30-year time horizon and the cost per quality-adjusted life year (QALY). The model adopted the National Health Service perspective and discounted future costs and benefits at 3.5%. RESULTS: Compared with current practice, alternative surveillance strategies resulted in up to a 4% reduction in the number of elective AAA repairs but with an increase of up to 1.6% in the number of AAA ruptures and AAA-related deaths. Alternative strategies resulted in a small reduction in QALYs compared to current practice but with reduced costs. Two strategies that lengthened surveillance intervals in only very small AAAs (3.0-3.9 cm) provided, at a cost-effectiveness threshold of £20 000 per QALY, the highest positive incremental net benefit. There was negligible chance that current practice is the most cost-effective strategy at any threshold below £40 000 per QALY. CONCLUSIONS: Lengthening surveillance intervals in the UK Abdominal Aortic Aneurysm Screening Programme, especially for small AAA, can marginally reduce the incremental cost per QALY of the program. Nevertheless, whether the cost savings from refining surveillance strategies justifies a change in clinical practice is unclear.

Impact of Digital Health Monitoring in the Management of Inflammatory Bowel Disease.

Technological advances now permit self-management strategies using mobile applications which could greatly benefit patient care. The purpose of this study was to investigate whether the use of the inflammatory bowel disease (IBD) digital health monitoring platform, HealthPROMISE, leads to better quality of care and improved health outcomes in IBD patients. IBD patients were recruited in gastroenterology clinics and asked to install the HealthPROMISE application onto their smartphones. Patient satisfaction, quality of care, quality of life, patient symptoms, and resource utilization metrics were collected throughout the study and sent directly to their healthcare teams. Patients with abnormal symptom/SIBDQ scores were flagged for their physicians to follow up. After one-year, patient outcome metrics were compared to baseline values. Overall, out of 59 patients enrolled in the study, 32 patients (54%) logged into the application at least once during the study period. The number of IBD-related ER visits/hospitalizations in the year of use compared to the prior year demonstrated a significant decrease from 25% of patients (8/32) to 3% (1/32) (p = 0.03). Patients also reported an increase in their understanding of the nature/causes of their condition after using the application (p = 0.026). No significant changes were observed in the number of quality indicators met (p = 0.67) or in SIBDQ scores (p = 0.48). Given the significant burden of IBD, there is a need to develop effective management strategies. This study demonstrated that digital health monitoring platforms may aid in reducing the number of ER visits and hospitalizations in IBD patients.

Economic evaluation alongside the Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial (E-PROSPECT): study protocol.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is a common healthcare-associated infection in the intensive care unit (ICU). Probiotics are defined as live microorganisms that may confer health benefits when ingested. Prior randomised trials suggest that probiotics may prevent infections such as VAP and Clostridioides difficile-associated diarrhoea (CDAD). PROSPECT (Probiotics to Prevent Severe Pneumonia and Endotracheal Colonization Trial) is a multicentre, double-blinded, randomised controlled trial comparing the efficacy of the probiotic Lactobacillus rhamnosus GG with usual care versus usual care without probiotics in preventing VAP and other clinically important outcomes in critically ill patients admitted to the ICU. METHODS AND ANALYSIS: The objective of E-PROSPECT is to determine the incremental cost-effectiveness of L. rhamnosus GG plus usual care versus usual care without probiotics in critically ill patients. E-PROSPECT will be performed from the public healthcare payer's perspective over a time horizon from ICU admission to hospital discharge.We will determine probabilities of in-ICU and in-hospital events from all patients alongside PROSPECT. We will retrieve unit costs for each resource use item using jurisdiction-specific public databases, supplemented by individual site unit costs if such databases are unavailable. Direct costs will include medications, personnel costs, radiology/laboratory testing, operative/non-operative procedures and per-day hospital 'hoteling' costs not otherwise encompassed. The primary outcome is the incremental cost per VAP prevented between the two treatment groups. Other clinical events such as CDAD, antibiotic-associated diarrhoea and in-hospital mortality will be included as secondary outcomes. We will perform pre-specified subgroup analyses (medical/surgical/trauma; age; frailty status; antibiotic use; prevalent vs no prevalent pneumonia) and probabilistic sensitivity analyses for VAP, then generate confidence intervals using the non-parametric bootstrapping approach. ETHICS AND DISSEMINATION: Study approval for E-PROSPECT was granted by the Hamilton Integrated Research Ethics Board of McMaster University on 29 July 2019. Informed consent was obtained from the patient or substitute decision-maker in PROSPECT. The findings of this study will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT01782755; Pre-results.

Vector bionomics and vectorial capacity as emergent properties of mosquito behaviors and ecology.

Mosquitoes are important vectors for pathogens that infect humans and other vertebrate animals. Some aspects of adult mosquito behavior and mosquito ecology play an important role in determining the capacity of vector populations to transmit pathogens. Here, we re-examine factors affecting the transmission of pathogens by mosquitoes using a new approach. Unlike most previous models, this framework considers the behavioral states and state transitions of adult mosquitoes through a sequence of activity bouts. We developed a new framework for individual-based simulation models called MBITES (Mosquito Bout-based and Individual-based Transmission Ecology Simulator). In MBITES, it is possible to build models that simulate the behavior and ecology of adult mosquitoes in exquisite detail on complex resource landscapes generated by spatial point processes. We also developed an ordinary differential equation model which is the Kolmogorov forward equations for models developed in MBITES under a specific set of simplifying assumptions. While mosquito infection and pathogen development are one possible part of a mosquito's state, that is not our main focus. Using extensive simulation using some models developed in MBITES, we show that vectorial capacity can be understood as an emergent property of simple behavioral algorithms interacting with complex resource landscapes, and that relative density or sparsity of resources and the need to search can have profound consequences for mosquito populations' capacity to transmit pathogens.

Repeat screening for syphilis in pregnancy as an alternative screening strategy in the UK: a cost-effectiveness analysis.

OBJECTIVES: To assess the cost-effectiveness of universal repeat screening for syphilis in late pregnancy, compared with the current strategy of single screening in early pregnancy with repeat screening offered only to high-risk women. DESIGN: A decision tree model was developed to assess the incremental costs and health benefits of the two screening strategies. The base case analysis considered short-term costs during the pregnancy and the initial weeks after delivery. Deterministic and probabilistic sensitivity analyses and scenario analyses were conducted to assess the robustness of the results. SETTING: UK antenatal screening programme. POPULATION: Hypothetical cohort of pregnant women who access antenatal care and receive a syphilis screen in 1 year. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the cost to avoid one case of congenital syphilis (CS). Secondary outcomes were the cost to avoid one case of intrauterine fetal demise (IUFD) or neonatal death and the number of women needing to be screened/treated to avoid one case of CS, IUFD or neonatal death. The cost per quality-adjusted life year gained was assessed in scenario analyses. RESULTS: Base case results indicated that for pregnant women in the UK (n=725 891), the repeat screening strategy would result in 5.5 fewer cases of CS (from 8.8 to 3.3), 0.1 fewer cases of neonatal death and 0.3 fewer cases of IUFD annually compared with the single screening strategy. This equates to an additional £1.8 million per case of CS prevented. When lifetime horizon was considered, the incremental cost-effectiveness ratio for the repeat screening strategy was £120 494. CONCLUSIONS: Universal repeat screening for syphilis in pregnancy is unlikely to be cost-effective in the current UK setting where syphilis prevalence is low. Repeat screening may be cost-effective in countries with a higher syphilis incidence in pregnancy, particularly if the cost per screen is low.

Loneliness in Primary Care Patients: A Prevalence Study.

PURPOSE: Loneliness has important health consequences. Little is known, however, about loneliness in primary care patient populations. This study describes the prevalence of loneliness in patients presenting for primary care and associations with self-reported demographic factors, health care utilization, and health-related quality of life. METHODS: We conducted cross-sectional surveys of adults presenting for routine care to outpatient primary care practices in 2 diverse practice-based research networks. The 3-item University of California, Los Angeles Loneliness Scale was utilized to determine loneliness. RESULTS: The prevalence of loneliness was 20% (246/1,235). Loneliness prevalence was inversely associated with age (P <.01) and less likely in those who were married (P <.01) or employed (P <.01). Loneliness was more common in those with lower health status (P <.01), including when adjusting for employment and relationship status (odds ratio [OR] = 1.05; 95% CI, 1.03-1.07). Primary care visits (OR = 1.07; 95% CI, 1.03-1.10), urgent care/emergency department visits (OR = 1.24; 95% CI, 1.12-1.38), and hospitalizations (OR = 1.15; 95% CI, 1.01-1.31) were associated with loneliness status. There was no significant difference in rates of loneliness between sexes (P = .08), racial categories (P = .57), or rural and urban respondents (P = .42). CONCLUSIONS: Our findings demonstrate that loneliness is common in primary care patients and is associated with adverse health consequences including poorer health status and greater health care utilization. Further work is needed to understand the value of screening for and using interventions to treat loneliness in primary care.

Socioeconomic and geographical disparities in prescription and illicit opioid-related overdose deaths in Orange County, California, from 2010-2014.

Background: Reports indicate a geographic effect of socioeconomic inequalities on the occurrence of opioid-related fatal overdoses. This study aims to (1) estimate the rates of opioid-related overdoses, (2) estimate the association of benzodiazepine co-ingestion with opioid-related deaths, (3) estimate associations between socioeconomic indicators and opioid-related deaths, and (4) map the distribution of fatal overdoses, in Orange County (OC), California. Methods: An ecologic study was conducted of all opioid- related deaths (1205 total) from 2010 to 2014 obtained from the OC Coroner Division database (1065 OC residents, 55 nonresidents, 85 OC homeless) (analyzed 2016-2017). Rates of opioid overdose, benzodiazepine co-ingestion prevalence, and associations with socioeconomic status (SES; education, poverty, median income) using ZIP code analysis in the residential and homeless communities were calculated. Results: Of 1205 deaths, 904 involved prescription-type opioids, 223 involved heroin, 39 involved both, and 39 not stated; 973 were classified unintentional overdoses, 180 suicides, and 52 undetermined; 49% of cases involved benzodiazepines. Prescription-type opioid and heroin death rates for residents were 5.4/ 100,000 person-years (95% confidence interval [CI]: 5.0-5.8) and 1.2/100,000 person-years (95% CI: 1.0-1.4), respectively. Males, age group 45-54, and Caucasian race had the highest rate (13.6/100,000) of opioid mortality. The highest death rates were seen in homeless adults, at 136/100,000 person-years for prescription-type opioids (95% CI: 99.0-185.5) and 156/100,000 person-years for heroin (95% CI: 116.8-209.5). Conclusions: The burden of prescription-type opioid-related deaths in OC affects all demographics and levels of SES; there is a disproportionately high rate of opioid-related deaths in the OC homeless population.