scholarly journals Probabilistic Approach to Conditional Probability of Release of Hazardous Materials From Railroad Tank Cars During Accidents

2009 ◽  
Author(s):  
D. Y. Jeong
Keyword(s):  
Sensitivity Analysis ◽  
Conditional Probability ◽  
Impact Velocity ◽  
Probabilistic Sensitivity Analysis ◽  
Probabilistic Approach ◽  
Hazardous Materials ◽  
Relative Effect ◽  
Distribution Functions ◽  
Mean Values ◽  
Effective Collision

This paper describes a probabilistic approach to estimate the conditional probability of release of hazardous materials from railroad tank cars during train accidents. Monte Carlo methods are used in developing a probabilistic model to simulate head impacts. The model is based on the physics of impact in conjunction with assumptions regarding the probability distribution functions of the various factors that affect the loss of lading. These factors include impact velocity, indenter size, tank material, tank diameter, effective collision mass, and tank thickness. Moreover, each factor is treated as a random variable characterized by its assumed distribution function, mean value, and standard deviation (or variance). Reverse engineering is performed to back-calculate the mean values and standard deviations of these random variables that reproduce trends observed in available accident data. The calibrated model is then used to conduct a probabilistic sensitivity analysis to examine the relative effect of these factors on the conditional probability of release. Results from the probabilistic sensitivity analysis indicate that the most significant factors that affect conditional probability of release are impact velocity, effective collision mass, and indenter size.

scholarly journals Probabilistic sensitivity analysis for multivariate model outputs with applications to Li-ion batteries

2018 ◽  
Vol 1039 ◽  
pp. 012020 ◽  
Author(s):  
V. Triantafyllidiis ◽  
W.W. Xing ◽  
P.K. Leung ◽  
A. Rodchanarowan ◽  
A.A. Shah
Keyword(s):  
Sensitivity Analysis ◽  
Probabilistic Sensitivity Analysis ◽  
Multivariate Model ◽  
Li Ion Batteries ◽  
Li Ion

scholarly journals Telemammography for breast cancer screening: a cost-effective approach in Argentina

2021 ◽  
Vol 28 (1) ◽  
pp. e100351
Author(s):  
Victoria Alba Malek Pascha ◽  
Li Sun ◽  
Ramiro Gilardino ◽  
Rosa Legood
Keyword(s):  
Breast Cancer ◽  
Sensitivity Analysis ◽  
Cancer Screening ◽  
Breast Cancer Screening ◽  
Probabilistic Sensitivity Analysis ◽  
Mammography Screening ◽  
Cost Effective ◽  
Access To Healthcare ◽  
Over 40 Years ◽  
Improve Access

ObjectivesArgentina is a low and middle-income country (LMIC) with a highly fragmented healthcare system that conflicts with access to healthcare stated by the country’s Universal Health Coverage plan. A tele-mammography network could improve access to breast cancer screening decreasing its mortality. This research aims to conduct an economic evaluation of the implementation of a tele-mammography program to improve access to healthcare.MethodsA cost-utility analysis was performed to explore the incremental benefit of annual tele-mammography screening for at-risk Argentinian women over 40 years old. A Markov model was developed to simulate annual mammography or tele-mammography screening in two hypothetical population-based cohorts of asymptomatic women. Parameter uncertainty was evaluated through deterministic and probabilistic sensitivity analysis. Model structure uncertainty was also explored to test the robustness of the results.ResultsIt was estimated that 31 out of 100 new cases of breast cancer would be detected by mammography and 39/100 by tele-mammography. The model returned an incremental cost-effectiveness ratio (ICER) of £26 051/quality-adjusted life-year (QALY) which is lower than the WHO-recommended threshold of £26 288/QALY for Argentina. Deterministic sensitivity analysis showed the ICER is most sensitive to the uptake and sensitivity of the screening tests. Probabilistic sensitivity analysis showed tele-mammography is cost-effective in 59% of simulations.DiscussionTele-mammography should be considered for adoption as it could improve access to expertise in underserved areas where adherence to screening protocols is poor. Disaggregated data by province is needed for a better- informed policy decision. Telemedicine could also be beneficial in ensuring the continuity of care when health systems are under stress like in the current COVID-19 pandemic.ConclusionThere is a 59% chance that tele-mammography is cost-effective compared to mammography for at-risk Argentinian women over 40- years old, and should be adopted to improve access to healthcare in underserved areas of the country.

scholarly journals Cost-effectiveness of pembrolizumab for treatment of platinum-resistant recurrent or metastatic head and neck squamous cell carcinoma in China: an economic analysis based on a randomised, open-label, phase III trial

BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e038867 ◽  
Author(s):  
Wenxiu Xin ◽  
Haiying Ding ◽  
Qilu Fang ◽  
Xiaowei Zheng ◽  
Yinghui Tong ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Squamous Cell Carcinoma ◽  
Cost Effectiveness ◽  
Cell Carcinoma ◽  
Head And Neck ◽  
Squamous Cell ◽  
Probabilistic Sensitivity Analysis ◽  
Cost Effective ◽  
Platinum Resistant ◽  
The Cost

BackgroundPembrolizumab was recently demonstrated to have survival benefit in patients with recurrent or metastatic head and neck squamous cell carcinoma (r/mHNSCC). However, the cost-effectiveness of pembrolizumab versus chemotherapy in China remains uncertain.ObjectiveThis analysis aimed to describe the cost-effectiveness of pembrolizumab versus standard-of-care (SOC) therapy in r/mHNSCC in China.DesignA Markov model consisting of three health states (stable, progressive and dead) was developed to compare the cost and effectiveness of pembrolizumab with SOC in platinum-resistant r/mHNSCC. Model inputs for transition probabilities and toxicity were collected from the KEYNOTE-040 trial, while health utilities were estimated from a literature review. Cost data were acquired for the payer’s perspective in China. Costs and outcomes were discounted at an annual rate of 3.0%. Sensitivity analyses were conducted to test the uncertainties surrounding model parameters.Outcome measuresThe primary outcome was incremental cost-effectiveness ratios (ICERs), which were calculated as the cost per quality-adjusted life years (QALYs).ResultsThe total mean cost of pembrolizumab and SOC was US$45 861 and US$41 950, respectively. As for effectiveness, pembrolizumab yielded 0.31 QALYs compared with 0.25 QALYs for SOC therapy. The ICER for pembrolizumab versus SOC was US$65 186/QALY, which was higher than the willingness-to-pay threshold (WTP) of US$28 130/QALY in China. The univariate sensitivity analysis indicated that utility values for progressive state, probability from stable to progressive in the SOC group, as well as cost of pembrolizumab were the three most influential variables on ICER. The probabilistic sensitivity analysis demonstrated that standard therapy was more likely to be cost-effective compared with pembrolizumab at a WTP value of US$28 130/QALY. Results were robust across both univariate analysis and probabilistic sensitivity analysis.ConclusionsPembrolizumab is not likely to be a cost-effective strategy compared with SOC therapy in patients with platinum-resistant r/mHNSCC in China.Trial registration numberNCT02252042; Post-results.

Design Nomographs of Compression Helical Springs for Predetermined Reliability Levels

1981 ◽  
Vol 103 (2) ◽  
pp. 268-273
Author(s):  
My Dao Thien ◽  
M. Massoud
Keyword(s):  
Probabilistic Approach ◽  
Design Procedure ◽  
Axial Loading ◽  
Geometric Parameters ◽  
Computer Algorithms ◽  
Mean Values ◽  
Helical Springs ◽  
Reliability Level ◽  
Classical Design ◽  
Mission Success

This paper discusses a probabilistic approach for the design of Compression Closely Coiled Helical Springs subjected to periodic axial loading. The classical design procedure results in deterministic geometric parameters with tolerances normally chosen according to standards without due regard to their effects on the mission success as normally expressed by a reliability level. With the proposed design procedure, the engineer can specify nominal mean values for the geometric parameters and their tolerances according to a predetermined reliability level. Design nomographs are presented to help the engineer, in the early stages of design, to choose between many alternatives. Computer algorithms can easily be written to verify the final or optimum design.

Cost-effectiveness of dual-mobility components in patients with displaced femoral neck fractures

2021 ◽  
Vol 103-B (12) ◽  
pp. 1783-1790
Author(s):  
Spencer Montgomery ◽  
Jonathan Bourget-Murray ◽  
Daniel Z. You ◽  
Leo Nherera ◽  
Amir Khoshbin ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Femoral Neck ◽  
Incremental Cost ◽  
Probabilistic Sensitivity Analysis ◽  
Cost Effective ◽  
Physiological Age ◽  
Base Case ◽  
Dual Mobility ◽  
Displaced Femoral Neck Fractures

Aims Total hip arthroplasty (THA) with dual-mobility components (DM-THA) has been shown to decrease the risk of dislocation in the setting of a displaced neck of femur fracture compared to conventional single-bearing THA (SB-THA). This study assesses if the clinical benefit of a reduced dislocation rate can justify the incremental cost increase of DM-THA compared to SB-THA. Methods Costs and benefits were established for patients aged 75 to 79 years over a five-year time period in the base case from the Canadian Health Payer’s perspective. One-way and probabilistic sensitivity analysis assessed the robustness of the base case model conclusions. Results DM-THA was found to be cost-effective, with an estimated incremental cost-effectiveness ratio (ICER) of CAD $46,556 (£27,074) per quality-adjusted life year (QALY). Sensitivity analysis revealed DM-THA was not cost-effective across all age groups in the first two years. DM-THA becomes cost-effective for those aged under 80 years at time periods from five to 15 years, but was not cost-effective for those aged 80 years and over at any timepoint. To be cost-effective at ten years in the base case, DM-THA must reduce the risk of dislocation compared to SB-THA by at least 62%. Probabilistic sensitivity analysis showed DM-THA was 58% likely to be cost-effective in the base case. Conclusion Treating patients with a displaced femoral neck fracture using DM-THA components may be cost-effective compared to SB-THA in patients aged under 80 years. However, future research will help determine if the modelled rates of adverse events hold true. Surgeons should continue to use clinical judgement and consider individual patients’ physiological age and risk factors for dislocation. Cite this article: Bone Joint J 2021;103-B(12):1783–1790.

Quantifying electron transit in donor-bridge-acceptor systems using probabilistic confidence

2018 ◽  
Vol 17 (07) ◽  
pp. 1850046 ◽  
Author(s):  
Evan Curtin ◽  
Gloria Bazargan ◽  
Karl Sohlberg
Keyword(s):  
Charge Transport ◽  
Conditional Probability ◽  
Probabilistic Approach ◽  
Probability Analysis ◽  
Time Dependent ◽  
Quantum Particles ◽  
Transit Times ◽  
Conditional Probability Analysis ◽  
Insight Into ◽  
Dependent Probability

A probabilistic approach to characterizing transit times for quantum particles is generalized to a system of more than two spatial regions and applied to the transport of charge in donor-bridge-acceptor systems. The approach is based on applying conditional probability analysis to a discrete representation of the time-dependent probability density as generated by numerical solution of the time-dependent Schrödinger equation for an initially localized electron. To carry out this analysis, it is first necessary to cast the conditional probability analysis approach in matrix form. The results afford a quantification of the electron transit time and may provide a tool to gain insight into the mechanism of charge transport.

scholarly journals A New Approach for Sampling Ordered Parameters in Probabilistic Sensitivity Analysis

2017 ◽  
Vol 36 (3) ◽  
pp. 341-347 ◽  
Author(s):  
Shijie Ren ◽  
Jonathan Minton ◽  
Sophie Whyte ◽  
Nicholas R. Latimer ◽  
Matt Stevenson
Keyword(s):  
Sensitivity Analysis ◽  
Probabilistic Sensitivity Analysis ◽  
New Approach
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