Multivariate Sensitivity Research Articles

Bowel cancer diagnosis experiences as a predictor of overall care rating: evidence from the English Cancer Patient Experience Survey

ObjectiveTo investigate whether and which negative diagnosis-related experiences of patients newly diagnosed with colorectal cancer (CRC) are associated with a poorer overall rating of care, to help prioritise interventions.MethodsA secondary...

Analytical model for CO2-water displacement with rate-dependent phase permeability for geological storage

Analytical modelling is an effective tool for predicting reservoir behaviour under high uncertainties, like CO2 storage in aquifers, where multiple simulation runs are necessary for stochastic modelling and risk assessment. This paper formulates the Buckley-Leverett problem with x-dependent fractional flow. We derive a new analytical model for displacement of brine by CO2 accounting for (i) rate-dependent phase permeability during radial flows and (ii) radial flows of Forchheimer’s high-rate gas injection; this analytical model is also valid for (iii) linear flows during flooding in micro heterogeneous or composite cores and (iv) CO2-water flow upscaling in reservoir where layering is perpendicular to flux direction. An exact solution of the flow equation is based on the observation that the flux of each phase conserves along the characteristic trajectories. We discuss S-shape fractional flow function, which is typical for reservoir rocks. The solution includes formulae for phase saturations and fluxes and trajectories of the displacement CO2-water front and of the forward and rear mixture zone boundaries. Fast analytical model can be used for multivariate sensitivity study and sweep efficiency prediction.

A combination of ANNs and multivariate sensitivity analysis unveils critical factors to increase androgenesis efficiency in tomato (Solanum lycopersicum)

A combination of ANNs and multivariate sensitivity analysis unveils critical factors to increase androgenesis efficiency in tomato (Solanum lycopersicum)

Soft sensor modeling method and application based on TSECIT2FNN-LSTM

To address the issue of low accuracy in soft sensor modeling of key variables caused by multi-variable coupling and parameter sensitivity in complex processes, this paper introduces a TSK-type-based self-evolving compensatory interval type-2 fuzzy Long short-term memory (LSTM) neural network (TSECIT2FNN-LSTM) soft sensor model. The proposed TSECIT2FNN-LSTM integrates the LSTM neural network with the interval type-2 fuzzy inference system to address long-term dependencies in sequence data by utilizing the gate mechanism of the LSTM neural network. The TSECIT2FNN-LSTM structure learning algorithm uses the firing strength of the network rule antecedent to decide whether to generate new rules to improve the rationality of the network structure. TSECIT2FNN-LSTM parameter learning utilizes the gradient descent method to optimize network parameters. However, unlike other interval type-2 fuzzy neural network gradient calculation processes, the error term in the LSTM node parameter gradient of TSECIT2FNN-LSTM is propagated backwards in the time dimension. Additionally, the error term is simultaneously transferred to the upper layer network to enhance network prediction accuracy and memory capabilities. The TSECIT2FNN-LSTM soft sensor model is utilized to predict the alcohol concentration in wine and the nitrogen oxide emission in gas turbines. Experimental results demonstrate that the proposed TSECIT2FNN-LSTM soft sensing model achieves higher prediction accuracy compared to other models.

Multivariate sensitivity-adaptive polynomial chaos expansion for high-dimensional surrogate modeling and uncertainty quantification

This work develops a novel basis-adaptive method for constructing anisotropic polynomial chaos expansions of multidimensional (vector-valued, multi-output) model responses. The adaptive basis selection is based on multivariate sensitivity analysis metrics that can be estimated by post-processing the polynomial chaos expansion and results in a common anisotropic polynomial basis for the vector-valued response. This allows the application of the method to problems with up to moderately high-dimensional model inputs (in the order of tens) and up to very high-dimensional model responses (in the order of thousands). The method is applied to different engineering test cases for surrogate modeling and uncertainty quantification, including use cases related to electric machine and power grid modeling and simulation, and is found to produce highly accurate results with comparatively low data and computational demand.

Association between inflammatory biomarkers and postoperative acute kidney injury after cardiac surgery in patients with preoperative renal dysfunction: a retrospective pilot analysis

BackgroundAcute kidney injury (AKI) represents a significant post-cardiac surgery complication, particularly prevalent among individuals with pre-existing renal dysfunction. Chronic kidney disease (CKD) is frequently accompanied by persistent, low-grade inflammation, which is known to exacerbate systemic stress responses during surgical procedures. This study hypothesizes that these inflammatory responses might influence the incidence and severity of postoperative acute kidney injury (AKI), potentially serving as a protective mechanism by preconditioning the kidney to stress.MethodsThis retrospective study enrolled patients with preoperative renal dysfunction (eGFR between 15 and 60 ml/min/1.73 m²) who underwent cardiac surgery between January 2020 and December 2022. Preoperative inflammatory biomarkers were evaluated. The primary outcome was the incidence of postoperative AKI, as defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Multivariate regression models and sensitivity analyses were conducted to ascertain the relationship between inflammatory biomarkers and AKI. Restricted cubic spines (RCS) was conducted to explore nonlinear associations between inflammatory biomarkers and AKI.ResultsAKI occurred in 53.4% (392/734) of patients, accompanied by significant mortality and length of hospital stay increases in cases of AKI (P < 0.005). After full adjustment of confounders, neutrophil percentage-to-albumin ratio (OR = 0.28), systemic inflammation response index (OR = 0.70), systemic immune inflammation index (OR = 0.69), neutrophil-to-lymphocyte ratio (OR = 0.70), monocyte/high-density lipoprotein cholesterol ratio (OR = 0.53), neutrophil/high-density lipoprotein cholesterol ratio (OR = 0.43) demonstrated an inverse association with AKI. Sensitivity analyses revealed that patients in the highest quartile of these biomarkers exhibited a significantly lower prevalence of AKI compared to those in the lowest quartile (p for trend < 0.05). The RCS analysis suggested an “Inverted U-shaped” association of both LnNPAR and LnSIRI with AKI.ConclusionsThis study identified an inverse association between preoperative inflammatory biomarkers and postoperative AKI in patients with preoperative renal dysfunction. The findings implied that preoperative inflammation may play a protective role against postoperative AKI in this patient population undergoing cardiac surgery.

Association of herpes simplex virus infection with hearing loss: a cross-sectional study using NHANES data from 2011 to 2012 and 2015 to 2016

ObjectivesTo investigate the relationship between herpes simplex virus (HSV) and hearing loss using comprehensive population-based research.DesignThis cross-sectional study utilised data from the National Health and Nutrition Examination Survey (NHANES) to...

The association between joint Serum Neurofilament Light Chain and type 2 diabetes with all-cause and cardiovascular mortality in US adults: a longitudinal study of NHANES

BackgroundIn the past, there has been a clear conclusion regarding the sole impact of serum neurofilament light chain (sNfL) levels or type 2 diabetes mellitus (DM) on the risk of death. However, the combined effect of sNfL levels and type 2 DM on all-cause and cardiovascular mortality is still uncertain.MethodsThis study was a prospective cohort study based on data from the National Health and Nutrition Examination Survey (NHANES). The sNfL levels were measured through immunological methods using blood samples collected during the survey. The diagnosis of diabetes was based on rigorous criteria, and participants’ mortality data were followed up until December 31, 2019. Firstly, we separately examined the effects of sNfL and type 2 DM on all-cause and cardiovascular mortality, and finally studied the comprehensive impact of the combination of sNfL and type 2 DM on the risk of mortality. Cumulative Kaplan-Meier curves, multivariate logistic regression and sensitivity analysis were incorporated throughout the entire study.ResultsParticipants in the highest quartile of sNfL were observed. Multivariable COX regression model showed that increased sNfL levels and type 2 DM were respectively associated with an increased risk of all-cause and cardiovascular mortality. Furthermore, elevated sNfL levels were significantly associated with an increased risk of all-cause mortality and cardiovascular mortality after adjustment for confounding factors. When considering both elevated sNfL levels and type 2 DM, individuals had a significantly increased risk of mortality. Sensitivity analysis confirmed the robustness of the findings.ConclusionsThese results suggest that elevated levels of sNfL and type 2 DM are associated with an increased risk of all-cause and cardiovascular mortality, and that participants with increased sNfL levels associated with type 2 DM have higher all-cause mortality and cardiovascular mortality.

Clinical Characteristics Associated with the PLP-PLS Index, a New Potential Metric to Phenotype Phantom Limb Pain.

Phantom limb pain (PLP) is highly prevalent after amputation. However, the influence of non-painful sensations (PLS) remains unclear. This study examines the PLP-PLS index as a novel tool to differentiate PLP from PLS and explores the association of clinical factors with the index. We conducted a cross-sectional analysis of baseline data from 112 participants in a previous factorial trial in patients with unilateral traumatic lower limb amputation. Linear regression models were used to examine the associations between the index and various demographic, psychological and clinical factors. Logistic and Poisson regression, and e-value calculation were utilized for sensitivity analyses. Adjusted multivariable linear regression models demonstrated significant associations of phantom movement sensation (β: -1.532; 95% CI: -2.615 to -0.449; p = 0.006) and time since amputation (β: 0.005; 95% CI: 0.0006 to 0.0101; p = 0.026) with the PLP-PLS index. These findings were confirmed by multivariable logistic regression (phantom movement sensation OR: 0.469; 95% CI: 0.200 to 1.099, p = 0.082; time since amputation OR: 1.003; 95% CI: 1.00003 to 1.007; p = 0.048) and sensitivity analyses. Time since amputation and phantom movement sensation likely reflect distinct phenotypes and potential mechanisms for PLP and PLS. The PLP-PLS index is a promising clinical tool for selecting therapies to prevent/treat PLP and for measuring treatment effects to modulate phantom pain. These findings emphasize the importance of understanding the mechanisms underlying PLP and PLS for improving clinical management and guiding future research.

HPV vaccination strategy for 14-year-old females and economic returns for cervical cancer prevention in Wuxi City, China: a cost effectiveness analysis

BackgroundSince December 2021, Wuxi, China has offered a two-dose human papillomavirus (HPV) vaccination to 14-year-old females for free. This study evaluated the costs and benefits of this vaccination scheduled in the Expanded Program on Immunization in Wuxi from the perspective of the cities’ demographic characteristics, economic development, and policy support.MethodsThe model-based economic evaluation used TreeAge Pro software to construct a decision tree-Markov model for the vaccination strategy in which 100,000 14-year-old females received two doses of bivalent HPV vaccine or no vaccination. Costs and effects of the strategy were assessed from a societal perspective through literature research and data obtained from the Wuxi Centre for Disease Control and Prevention. Univariate, multivariate, and probabilistic sensitivity analyses assessed the stability of the findings.ResultsThe cost of the bivalent HPV vaccine in Wuxi is 711.3 CNY. The two-dose of bivalent HPV vaccine for 100,000 14-year-old females would cost an additional 658,016 CNY compared to no vaccination, but would result in 1,960 Quality Adjustment Years of Life (QALYs). Using the per capita gross domestic product of 187,415 CNY in 2021 in Wuxi as the willingness-to-pay threshold, the vaccination strategy costs 3,357.37 CNY per QALY gained, which is much lower than the threshold, suggesting that it is a very cost-effective strategy. In addition, the vaccine strategy reduced the incidence of cervical cancer by 300 cases and cervical cancer deaths by 181 cases, representing a benefit-cost ratio of 2.86 (> 1) when health output outcomes were measured in monetary terms. These results suggested that the vaccination strategy was advantageous. Sensitivity analyses showed that changes in the parameters did not affect the conclusions and that the findings were robust.ConclusionsCompared to no vaccination, the delivery of two doses of bivalent HPV vaccine for 14-year-old females was a more highly cost-effective and optimal strategy.

Association of triglyceride glucose index with stroke: from two large cohort studies and Mendelian randomization analysis.

The triglyceride glucose index (TyG) is associated with cardiovascular diseases; however, its association with stroke remains unclear. This study aimed to elucidate this relationship by examining two extensive cohort studies using two-sample Mendelian randomization (MR). Using data from the 1999-2018 National Health and Nutrition Examination Survey (NHANES) and the Medical Information Mart for Intensive Care (MIMIC)-IV, the correlation between TyG (continuous and quartile) and stroke was examined using multivariate Cox regression models and sensitivity analyses. Two-sample MR was employed to establish causality between TyG and stroke using the inverse variance weighting method. Genome-wide association study catalog queries were performed for single nucleotide polymorphism-mapped genes, and the STRING platform used to assess protein interactions. Functional annotation and enrichment analyses were also conducted. From the NHANES and MIMIC-IV cohorts, we included 740 and 589 participants with stroke, respectively. After adjusting for covariates, TyG was linearly associated with the risk of stroke death (NHANES: hazard ratio [HR] 0.64, 95% CI: 0.41-0.99, P =0.047; Q3 vs. Q1, HR 0.62, 95% CI: 0.40-0.96, P =0.033; MIMIC-IV: HR 0.46, 95% CI: 0.27-0.80, P =0.006; Q3 vs. Q1, HR 0.32, 95% CI: 0.12-0.86; Q4 vs. Q1, HR 0.30, 95% CI: 0.10-0.89, P =0.030, P for trend=0.017). Two-sample MR analysis showed genetic prediction supported a causal association between a higher TyG and a reduced risk of stroke (odds ratio 0.711, 95% CI: 0.641-0.788, P =7.64e -11 ). TyG was causally associated with a reduced risk of stroke. TyG is a critical factor for stroke risk management.

Causal Relationship Between Gut Microbiota and Chronic Obstructive Pulmonary Disease: A Bidirectional Two-Sample Mendelian Randomization Study.

The associations between gut microbiota and chronic obstructive pulmonary disease (COPD) have gained increasing attention and research interest among scholars. However, it remains unclear whether gut microbiota serves as a causal factor for COPD or if it is a consequence of the disease. Therefore, we investigated the causal relationship between COPD and gut microbiota, with intention of providing novel insights and references for clinical diagnosis and treatment. Based on the genome-wide association study (GWAS) data, we employed MR-Egger regression, random-effects inverse variance-weighted (IVW) method, and weighted median method for bidirectional Mendelian randomization (MR) analysis. We conducted Cochran's Q test for heterogeneity assessment and performed multivariable analysis, sensitivity analysis, and heterogeneity testing to validate the reliability and stability of results. Utilizing MR analysis, mainly employing the IVW method, we detected a collective of 11 gut microbiota species that exhibited associations with COPD. Among them, Bacteroidia, family XIII, Clostridium innocuum group, Barnesiella, Collinsella, Lachnospiraceae NK4A136 group, Lachnospiraceae UCG004, Lachnospiraceae UCG010, and Bacteroidales were found to be protective factors for COPD. On the other hand, Holdemanella and Marvinbryantia were identified as risk factors for COPD. Individuals with elevated levels of Holdemanella exhibited a 1.141-fold higher risk of developing COPD compared to their healthy counterparts, and those with increased levels of Marvinbryantia had a 1.154-fold higher risk. Reverse MR analysis yielded no evidence indicating a causal relationship between gut microbiota and COPD occurrence. Our study established a causal link between 11 specific gut microbiota species and COPD, offering novel insights and valuable references for targeted therapies in the clinical management of COPD. However, our results were mainly based on the analysis of database, and further clinical studies are needed to clarify the effects of gut microbiota on COPD and its specific protective mechanism.

UMOD Genotype and Determinants of Urinary Uromodulin in African Populations

Background and objectivesSingle-nucleotide polymorphisms (SNPs) in the UMOD-PDILT genetic locus are associated with chronic kidney disease (CKD) in European populations, via their effect on urinary uromodulin (uUMOD) levels. The genetic and non-genetic factors associated with uUMOD in African populations remain unknown. MethodsClinical parameters, three selected UMOD-PDILT SNPs and uUMOD levels were obtained in 1202 young Black and White adults from the African-PREDICT study and 1943 middle aged Black adults from the PURE-NWP-SA study, two cross-sectional, observational studies. ResultsAbsolute uUMOD and uUMOD/creatinine levels were lower in Black participants compared to White participants. The prime CKD-risk allele at rs12917707 was more prevalent in Black individuals, with strikingly more risk allele homozygotes compared to White individuals. Haplotype analysis of the UMOD-PDILT locus predicted more recombination events and LD fragmentation in Black individuals. Multivariate testing and sensitivity analysis showed that higher uUMOD/creatinine associated specifically with risk alleles at rs12917707 and rs12446492 in White participants and with higher serum renin and lower uACR in Black participants with a significant interaction of ethnicity on the relationship between all three SNPs and uUMOD/creatinine. The multiple regression model explained a greater percentage of the variance of uUMOD/creatinine in White compared to Black adults (23% vs. 8%). ConclusionsWe evidenced ethnic differences in clinical and genetic determinants of uUMOD levels, in particular an interaction of ethnicity on the relationship between CKD-risk SNPs and uUMOD. These differences should be considered when analyzing the role of uromodulin in kidney function, interpreting GWAS, and precision medicine recommendations.

The Association Between Physical Activity and risk for breast cancer in US female adults: A cross-sectional study based on NHANES 2011–2020

BackgroundBreast cancer poses a significant threat to women's health worldwide. This study aimed to evaluate the association between various levels of physical activity and the incidence of breast cancer. MethodsThe data for this study were obtained from the National Health and Nutrition Examination Survey (NHANES), spanning 2011 to 2020. The study included female participants aged 20 years or older, who provided detailed data on breast cancer incidence, physical activity levels, and other pertinent variables. Adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using multivariate logistic regression analyses, alongside subgroup and sensitivity analyses. ResultsAfter adjusting for potential confounders, multivariate logistic regression analyses indicated that compared to individuals with low physical activity (<600 METs min/week), light physical activity (600 to < 1800 METs min/week), moderate physical activity (1800 to < 3000 METs min/week) and high physical activity (≥3000 METs min/week) were associated with breast cancer with adjusted ORs of 0.95 (95 % CI 0.68–1.34, P = 0.787), 0.92 (95 % CI 0.57–1.49, P = 0.747), and 0.56 (95 % CI 0.37–0.86, P = 0.009) respectively. These results were consistent across sensitivity and subgroup analyses. ConclusionHigh-intensity physical activity may decrease the risk of breast cancer, highlighting the importance of proactively implementing healthy lifestyle interventions to protect the health of adult women.

Impact of repositioning on brain injury following transcatheter aortic valve replacement with a self-expanding valve

Repositionable self-expanding valves allow for repositioning during deployment to achieve optimal valve placement. However, the risk of brain injury associated with repositioning, as detected by diffusion-weighted magnetic resonance imaging (DW-MRI), is unknown. Consecutive patients undergoing transcatheter aortic valve replacement (TAVR) with repositionable self-expanding valves and receiving DW-MRI before and within 7 days post-TAVR procedure were included. The primary outcomes were incidence, number, total volume, and volume per lesion of the cerebral ischemic lesion in DW-MRI after TAVR. Univariate and multivariate logistic regression assessed the association between repositioning and bigger total lesion volume (> 1 cm3 or > 0.5 cm3). Negative binomial regressions were performed to explore the association between repositioning and number of lesions. A propensity score matching was performed to adjust the potential confounders. Moreover, inverse probability of treatment weighted regression model with nonstabilized weights was used as sensitivity analysis. Among 243 included patients, repositioning was performed in 116 (47.7%) patients. The incidence of overt stroke (1.7% vs. 1.6%, p = 0.927) and silent stroke (86.2% vs. 85.8%, p = 0.932) were comparable between two groups. However, the number of new lesions (5.0 [2.0–9.0] vs. 3.0 [2.0–6.0], p = 0.048), and total lesion volume (275.0 [90.0–947.5] mm3 vs. 180.0 [50.0–440.0] mm3, p = 0.022) were significantly higher in the repositioned group. Moreover, the proportion of patients with lesion size greater than 0.5 cm3 was higher in the repositioned group (37.9% vs. 22.0%, p = 0.007). The similar results were observed after propensity score matching. In both multivariate regression model and sensitivity analysis, the repositioning was the independent predictor of number of lesions and bigger total lesion volume after TAVR. The utilization of the repositioning feature may increase the number and volume of silent brain infarcts in DW-MRI in patients who underwent TAVR. (Transcatheter Aortic Valve Replacement Single Center Registry in Chinese Population [TORCH]; NCT02803294)

Evaluation of multiparametric MRI differentiating pleomorphic adenoma from schwannoma in parapharyngeal space.

This study aimed to investigate whether multiparametric magnetic resonance imaging (MRI) including dynamic contrast-enhanced (DCE) and diffusion weighted (DW) MRI can differentiate pleomorphic adenoma (PA) from schwannoma in the parapharyngeal space. Forty-six patients with pathologically proven PAs and 47 schwannomas in the parapharyngeal space were enrolled. All patients underwent conventional MRI, and DW-MRI and DCE-MRI were performed in 30 and 33 patients, respectively. Fisher's exact, Mann-Whitney-U tests and Independent samples t-test were used to compare variables between PAs and schwannomas. Multivariate logistic regression analysis was used to examine the diagnostic performance of MRI parameters. The PAs usually show lobulation sign, posterior displacement of ICA and attached to the parotid gland deep leaf, while bird beak configuration, anterior displacement of ICA and involvement of foramen jugular were more commonly seen in the schwannomas(all p < 0.001). The washout rate of PAs was found to be higher than that of schwannomas (p = 0.035), whereas no significance was found in the other DCE-MRI parameters and in ADCs(p > 0.05). Using a combination of conventional MRI features including lobulation sign, bird beak configuration, direction of internal carotid artery(ICA) displacement and attached to the parotid gland in multivariate logistic regression analysis, sensitivity, specificity, and accuracy in differential diagnosis of PAs and schwannomas were 97.8%, 91.5% and 94.6%, respectively. Conventional MRI can effectively differentiate PAs from schwannomas in the parapharyngeal space with a high diagnostic accuracy. The DCE-MRI and DWI have limited added diagnostic value to conventional MRI in the differential diagnosis.

Association between lipoprotein(a), fibrinogen and their combination with all-cause, cardiovascular disease and cancer-related mortality: findings from the NHANES

BackgroundThere is evidence indicating that both lipoprotein(a) [Lp(a)] and fibrinogen (FIB) are associated with mortality, However, the impact of their combination on mortality has not been determined. Thus, the aim of this study was to examine the association between the combination of Lp(a) and FIB with all-cause and cause-specific mortality.MethodsThis prospective cohort study enrolled 4,730 participants from the third National Health and Nutrition Examination Survey. The exposure variables included Lp(a), FIB and their combination, while the outcome variables consisted of all-cause, cardiovascular disease (CVD) and cancer-related mortality. Multivariate COX regression, subgroup analysis, sensitivity analysis and restricted cubic spline (RCS) were used to investigate the association between Lp(a), FIB and their combination with all-cause, CVD and cancer-related mortality.ResultsOver a median follow-up period of 235 months, 2,668 individuals died, including 1,051 deaths attributed to CVD and 549 deaths due to cancer. Multivariate Cox regression analyses revealed independent associations between both Lp(a) and FIB with all-cause, CVD, and cancer-related mortality. Compared to participants in the 1st to 50th percentiles of both Lp(a) and FIB, those in the 90th to 100th percentiles exhibited multivariable adjusted HRs of 1.813 (95% CI: 1.419–2.317, P < 0.001), 2.147 (95% CI: 1.483–3.109, P < 0.001) and 2.355 (95% CI: 1.396, 3.973, P = 0.001) for all-cause, CVD and cancer-related mortality, respectively. Subgroup and sensitivity analyses did not substantially attenuate the association between the combination of high Lp(a) and high FIB with the risk of all-cause and CVD-related mortality. Additionally, the RCS analysis showed that the relationship between Lp(a) and the risk of all-cause and cancer-related mortality, as well as the relationship between FIB and the risk of cancer-related mortality, were linear (P for nonlinearity > 0.05). Conversely, the relationship between Lp(a) and the risk of CVD-related mortality, as well as the relationship between FIB and the risk of all-cause and CVD-related mortality, were nonlinear (P for nonlinearity < 0.05).ConclusionsHigh levels of Lp(a) and FIB together conferred a greater risk of mortality from all-cause, CVD and cancer.

Cost-effectiveness of a new multi-lumen infusion device to reduce central-venous-line-associated bloodstream infections in neonates

A new medical device was developed for multi-infusion in neonatal intensive care units (NICUs) with the aim of addressing issues related to drug incompatibilities and central-line-associated bloodstream infections (CLABSIs). To assess the cost-effectiveness of implementing this new perfusion system in an NICU setting. This single-centre, observational study was conducted in all infants admitted to the NICU within 3 days of birth, and who required a central venous line, to evaluate the cost and effectiveness before (2019) and after (2020) implementation of the new perfusion system. Costs were calculated from the hospital perspective, and the incidence of CLABSIs was examined over a time horizon from NICU admission to discharge. Resource utilization was measured (infusion device, infection-treating drugs and biological analyses), and corresponding costs were valued using tariffs for 2019. The incremental cost-effectiveness ratio (ICER) was calculated, expressed as Euros per CLABSI avoided, and one-way and multi-variate sensitivity analyses were conducted. Among 609 infants selected, clinical characteristics were similar across both periods. The CLABSI rate decreased significantly (rate ratio 0.22, 95% confidence interval 0.07-0.56), and total costs reduced from €65,666 to €63,932 per 1000 catheter-days (P<0.001) after implementation of the new perfusion system, giving an ICER of €251 saved per CLABSI avoided. The majority of sensitivity analyses showed that the new intervention remained economically dominant. This single-centre study showed a significant decrease in the incidence of CLABSIs after implementation of the new perfusion system, without incurring additional costs. Further prospective multi-centre randomized studies are needed to confirm these results in other NICUs.

The modified Mohr-Coulomb model considering softening effect and intermediate principal stress

Based on the Mohr-Coulomb model, a modified Mohr-Coulomb model that can consider both softening effect and intermediate principal stress effect was formed by introducing plastic internal variables that characterize material damage and a modified stress Rhodes angle. The modified model is numerically integrated by implicit algorithm, the physical meaning of the model parameters of the modified model is clarified, and the multivariate analysis and sensitivity analysis of the model parameters are carried out. Combined with the results of the gypsum triaxial test, the model parameters of the modified model were determined by the equation solving and RBF neural network optimization method, and the validity of the model was verified. The research results showed that: The modified model established can consider both the material softening effect and the influence of the intermediate principal stress. Compared with the traditional Mohr-Coulomb model, the calculation results of the modified model are more consistent with the test results qualitatively and quantitatively. The comprehensive use of direct determination, equation solving and RBF neural network optimization methods can effectively determine the model parameters of the modified model, and the determination process is relatively simple. It is suggested that this combined method can be used for subsequent determination of more complex constitutive model parameters. Compared with the traditional Mohr-Coulomb model, the modified model only needs one more true-triaxial test to determine the model parameters. In addition, the experience of using the parameters of the traditional Mohr-Coulomb model in a large number of engineering practices can be used to improve the model, so the modified model has great potential for engineering applications.

Clinicomicrobiological risk factors for infective endocarditis in viridans group streptococci bacteraemia.

When to perform echocardiography to rule out infective endocarditis (IE) in patients with viridans group streptococci (VGS) bloodstream infections (BSIs) is unclear. We aimed to identify independent risk factors for IE in patients with VGS BSI. This retrospective study conducted at Seoul National University Hospital from January 2013 to December 2022 involved patients with VGS and nutritionally variant streptococcal BSI, excluding single positive blood cultures and polymicrobial BSI cases. Independent risk factors were identified by multivariate logistic regression and sensitivity analyses according to echocardiography results, VGS species or the inclusion of possible IE cases. Of 845 VGS BSI cases, 349 were analysed and 86 IE cases were identified (24.6%). In the multivariate analysis, heart valve disease [adjusted odds ratio (aOR), 14.14, 95% CI, 6.14-32.58; P < 0.001], persistent bacteraemia (aOR, 5.12, 95% CI, 2.03-12.94; P = 0.001), age (per year, aOR, 0.98; 95% CI, 0.96-1.00; P = 0.015), solid cancer (aOR, 0.26; 95% CI, 0.13-0.53; P < 0.001) and haematologic malignancy (aOR, 0.04; 95% CI, 0.01-0.41; P = 0.006) were independently associated with IE. Sensitivity analyses yielded consistent results; also, infection by a member of the mitis group was independent risk factor for IE (aOR, 6.50; 95% CI, 2.87-14.68; P < 0.001). Younger age, heart valve disease, persistent bacteraemia, absence of underlying malignancy and BSI by a member of the mitis group were independent risk factors for IE in patients with VGS BSI. Echocardiographic evaluation could be prudently considered based on these clinicomicrobiological risk factors.