The Determination of Sequential Strategies of Diagnostic Tests: Comparison of Different Methods by Simulation

1979 ◽  
Vol 18 (02) ◽  
pp. 75-79 ◽  
Author(s):  
A. Alpérovitch ◽  
M. Le Minor ◽  
J. Lellouch
Keyword(s):  
Decision Tree ◽  
Diagnostic Test ◽  
Optimal Strategy ◽  
Diagnostic Tests ◽  
Computer Time ◽  
Simulated Patients ◽  
Test Strategies ◽  
The Cost ◽  
Sequential Strategy

Various heuristic processes for determining diagnostic test strategies were compared with the optimal sequential strategy on simulated patients. These heuristics consisted in limiting the depth and breadth of the search in the decision tree with regard to medically reasonable constraints. It appeared that some of these heuristics required a very small amount of computer time and provided solutions, the costs of which were very close to the cost of the optimal strategy.General conclusions were drawn from an analysis of the performance of these various heuristics for varying cost functions.

scholarly journals Prevalence-Value-Accuracy Plots: A New Method for Comparing Diagnostic Tests Based on Misclassification Costs

1999 ◽  
Vol 45 (7) ◽  
pp. 934-941 ◽  
Author(s):  
Alan T Remaley ◽  
Maureen L Sampson ◽  
James M DeLeo ◽  
Nancy A Remaley ◽  
Beriuse D Farsi ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Test Performance ◽  
Diagnostic Tests ◽  
Decision Threshold ◽  
Area Index ◽  
Misclassification Costs ◽  
Plot Analysis ◽  
Optimum Decision ◽  
Diagnostic Test Performance ◽  
The Cost

Abstract The clinical accuracy of diagnostic tests commonly is assessed by ROC analysis. ROC plots, however, do not directly incorporate the effect of prevalence or the value of the possible test outcomes on test performance, which are two important factors in the practical utility of a diagnostic test. We describe a new graphical method, referred to as a prevalence-value-accuracy (PVA) plot analysis, which includes, in addition to accuracy, the effect of prevalence and the cost of misclassifications (false positives and false negatives) in the comparison of diagnostic test performance. PVA plots are contour plots that display the minimum cost attributable to misclassifications (z-axis) at various optimum decision thresholds over a range of possible values for prevalence (x-axis) and the unit cost ratio (UCR; y-axis), which is an index of the cost of a false-positive vs a false-negative test result. Another index based on the cost of misclassifications can be derived from PVA plots for the quantitative comparison of test performance. Depending on the region of the PVA plot that is used to calculate the misclassification cost index, it can potentially lead to a different interpretation than the ROC area index on the relative value of different tests. A PVA-threshold plot, which is a variation of a PVA plot, is also described for readily identifying the optimum decision threshold at any given prevalence and UCR. In summary, the advantages of PVA plot analysis are the following: (a) it directly incorporates the effect of prevalence and misclassification costs in the analysis of test performance; (b) it yields a quantitative index based on the costs of misclassifications for comparing diagnostic tests; (c) it provides a way to restrict the comparison of diagnostic test performance to a clinically relevant range of prevalence and UCR; and (d) it can be used to directly identify an optimum decision threshold based on prevalence and misclassification costs.

scholarly journals Expression of multiple γ-glutamyltransferase genes in man

1994 ◽  
Vol 297 (3) ◽  
pp. 503-508 ◽  
Author(s):  
C Courtay ◽  
N Heisterkamp ◽  
G Siest ◽  
J Groffen
Keyword(s):  
Human Genome ◽  
Diagnostic Test ◽  
Diagnostic Tests ◽  
Oligonucleotide Probes ◽  
Gene Products ◽  
Biological Variability ◽  
Sequence Determination ◽  
Adult Liver ◽  
Gamma Glutamyltransferase

In clinical and pharmacological laboratories, the assay for gamma-glutamyltransferase (GGT) activity is an important diagnostic test, but one with high biological variability. Although the human genome contains multiple GGT genomic sequences, the diagnostic tests generally assume that only a single GGT gene is active. In the current study, segments encompassing parts of seven different potential human GGT genes have been molecularly cloned. Based on sequence determination of exons within these distinct genomic clones, oligonucleotide primers were designed which would prime and PCR-amplify putative mRNA of all seven potential GGT genes, if expressed. Gene-specific oligonucleotide probes were then utilized to assay the transcriptional status of the seven possible GGT genes in a wide variety of human RNAs. Our results show that a single GGT gene exhibits ubiquitous expression in all RNAs tested, including those from fetal and adult liver. A surprisingly large number of four additional GGT genes is expressed in man. Interestingly, these novel GGT genes are expressed in a tissue-restricted manner, which suggests that their corresponding gene products exhibit distinct functions in these specific tissues.

Learning Cost-Sensitive Decision Trees to Support Medical Diagnosis

2010 ◽  
pp. 287-307
Author(s):  
Alberto Freitas ◽  
Altamiro Costa-Pereira
Keyword(s):  
Decision Tree ◽  
Decision Trees ◽  
Diagnostic Test ◽  
Real World ◽  
Medical Diagnosis ◽  
Diagnostic Tests ◽  
Medical Data ◽  
Medical Applications ◽  
Total Cost ◽  
Wrong Diagnosis

Classification plays an important role in medicine, especially for medical diagnosis. Real-world medical applications often require classifiers that minimize the total cost, including costs for wrong diagnosis (misclassifications costs) and diagnostic test costs (attribute costs). There are indeed many reasons for considering costs in medicine, as diagnostic tests are not free and health budgets are limited. In this chapter, the authors have defined strategies for cost-sensitive learning. They have developed an algorithm for decision tree induction that considers various types of costs, including test costs, delayed costs and costs associated with risk. Then they have applied their strategy to train and to evaluate cost-sensitive decision trees in medical data. Generated trees can be tested following some strategies, including group costs, common costs, and individual costs. Using the factor of “risk” it is possible to penalize invasive or delayed tests and obtain patient-friendly decision trees.

scholarly journals Point-of-care diagnostic tests for influenza in the emergency department: A cost-effectiveness analysis in a high-risk population from a Canadian perspective

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242255
Author(s):  
Stephen Mac ◽  
Ryan O’Reilly ◽  
Neill K. J. Adhikari ◽  
Robert Fowler ◽  
Beate Sander
Keyword(s):  
Cost Effectiveness ◽  
High Risk ◽  
Diagnostic Test ◽  
Diagnostic Tests ◽  
Cost Effective ◽  
Old Patients ◽  
Influenza Like Illness ◽  
High Risk Patients ◽  
Risk Patients ◽  
The Cost

Background Our objective was to assess the cost-effectiveness of novel rapid diagnostic tests: rapid influenza diagnostic tests (RIDT), digital immunoassays (DIA), rapid nucleic acid amplification tests (NAAT), and other treatment algorithms for influenza in high-risk patients presenting to hospital with influenza-like illness (ILI). Methods We developed a decision-analytic model to assess the cost-effectiveness of diagnostic test strategies (RIDT, DIA, NAAT, clinical judgement, batch polymerase chain reaction) preceding treatment; no diagnostic testing and treating everyone; and not treating anyone. We modeled high-risk 65-year old patients from a health payer perspective and accrued outcomes over a patient’s lifetime. We reported health outcomes, quality-adjusted life years (QALYs), healthcare costs, and net health benefit (NHB) to measure cost-effectiveness per cohort of 100,000 patients. Results Treating everyone with no prior testing was the most cost-effective strategy, at a cost-effectiveness threshold of $50,000/QALY, in over 85% of simulations. This strategy yielded the highest NHB of 15.0344 QALYs, but inappropriately treats all patients without influenza. Of the novel rapid diagnostics, NAAT resulted in the highest NHB (15.0277 QALYs), and the least number of deaths (1,571 per 100,000). Sensitivity analyses determined that results were most impacted by the pretest probability of ILI being influenza, diagnostic test sensitivity, and treatment effectiveness. Conclusions Based on our model, treating high-risk patients presenting to hospital with influenza-like illness, without performing a novel rapid diagnostic test, resulted in the highest NHB and was most cost-effective. However, consideration of whether treatment is appropriate in the absence of diagnostic confirmation should be taken into account for decision-making by clinicians and policymakers.

Automated Development of Clinical Strategies Using Multistage Decision Analysis

1986 ◽  
Vol 25 (04) ◽  
pp. 207-214 ◽  
Author(s):  
P. Glasziou
Keyword(s):  
Decision Tree ◽  
Decision Analysis ◽  
Decision Trees ◽  
Optimal Strategy ◽  
Cholestatic Jaundice ◽  
Clinical Strategies ◽  
Simultaneous Study

SummaryThe development of investigative strategies by decision analysis has been achieved by explicitly drawing the decision tree, either by hand or on computer. This paper discusses the feasibility of automatically generating and analysing decision trees from a description of the investigations and the treatment problem. The investigation of cholestatic jaundice is used to illustrate the technique.Methods to decrease the number of calculations required are presented. It is shown that this method makes practical the simultaneous study of at least half a dozen investigations. However, some new problems arise due to the possible complexity of the resulting optimal strategy. If protocol errors and delays due to testing are considered, simpler strategies become desirable. Generation and assessment of these simpler strategies are discussed with examples.

Mekanisme Dan Proteksi Jaminan Nasabah Pada Gadai Informal

Liquidity ◽  
2017 ◽  
Vol 6 (2) ◽  
pp. 103-109
Author(s):  
Yuri Nanda Larasati ◽  
Jafril Khalil
Keyword(s):  
Qualitative Research ◽  
Research Methods ◽  
Financial Services ◽  
Field Data ◽  
Qualitative Research Methods ◽  
Research Field ◽  
Consumer Society ◽  
Library Research ◽  
The Cost

Regulation of the financial services authority (OJK) No. 31/POJK.05/2016 on Venture had arranged that the financial services agency on the basis of the law of pledge is in coaching and supervision OJK. Yet the existence of laws – invitation to Governing Enterprise pawn shops causing business activities conducted by the above parties are not yet regulated. The condition is feared could cause harm to the consumer society. The purpose of this research is to know the procedures, mechanisms, protection of goods and guarantee the consumer on an informal pledge financing, methods of determination of the cost of maintenance of the goods and the goods of the execution mechanism of the pledge as well as protection for the collateral items are viewed from the side of the consumer by looking at laws-invitations and Sharia. To find out whether the pledge have gotten permission from OJK. This research uses qualitative research methods with the study of library research, field data and simulations. The approach used in this study is the empirical juridical approach. Elaboration upon the results is discussed further in this article.

The Awareness Level of the Safety and Health of the Operational Level

2017 ◽  
Vol 3 (1) ◽  
pp. 42
Author(s):  
Roshanira Che Mohd Noor ◽  
Nur Atiqah Rochin Demong
Keyword(s):  
Health And Safety ◽  
Health Conditions ◽  
Effective Strategies ◽  
Operational Level ◽  
Safety And Health ◽  
Health Factors ◽  
The Cost ◽  
The Relationship ◽  
Awareness Level

Providing a safe and healthy workplace is one of the most effective strategies in for holding down the cost of doing construction business. It was a part of the overall management system to facilitate themanagement of the occupational health and safety risk that are associated with the business of the organization. Factors affected the awareness level inclusive of safety and health conditions, dangerous working area, long wait care and services and lack of emergency communication werethe contributed factors to the awareness level for the operational level. Total of 122 incidents happened at Telekom Malaysia Berhad as compared to year 2015 only 86 cases. Thus, the main objective of this study was to determine the relationship between safety and health factors and the awareness level among operational workers.The determination of this research was to increase the awareness level among the operational level workerswho committing to safety and health environment.

ANALISIS PERHITUNGAN HARGA POKOK PRODUKSI DAN PENENTUAN HARGA JUAL ATAS PRODUK (Studi Kasus Pada PT Dasa Windu Agung)

2016 ◽  
Vol 1 (2) ◽  
pp. 183-190
Author(s):  
Dwi Urip Wardoyo
Keyword(s):  
Manufacturing Industry ◽  
Sampling Method ◽  
Manufacturing Companies ◽  
Test Analysis ◽  
Automotive Components ◽  
Convenience Sampling ◽  
Cost Of Production ◽  
The Cost ◽  
Keywords Cost

This study aims to determine the determination of the cost of production for products produced by PT. DWA. The Company is engaged in the manufacturing industry specialized in automotive components. Its activity is carried out through a series of production processes, so that expenses spent in the production will be calculated into the cost of the production sold. The population in this study were all manufacturing companies in Jakarta. Convenience sampling method selected one of the companies that get the confidence to assemble three national car project in Indonesia, namely Timor, Bakrie and Maleo. Test analysis used in this study is to test the calculation of full costing with job order costing. This study shows that (a) determination of the cost elements associated with the cost of production and (b) determining the cost of production on a product-based job costing with full costing approach. Keywords: cost of production, full costing

Determination of the minimum number of technological bases of a part

2020 ◽  
pp. 73-75
Author(s):  
B.M. Bazrov ◽  
T.M. Gaynutdinov
Keyword(s):  
Cost Price ◽  
Labor Input ◽  
Part Surface ◽  
Technological Base ◽  
Size Accuracy ◽  
Minimum Number ◽  
The Cost ◽  
Input Cost ◽  
Selection Of

The selection of technological bases is considered before the choice of the type of billet and the development of the route of the technological process. A technique is proposed for selecting the minimum number of sets of technological bases according to the criterion of equality in the cost price of manufacturing the part according to the principle of unity and combination of bases at this stage. Keywords: part, surface, coordinating size, accuracy, design and technological base, labor input, cost price. [email protected]

Sign in / Sign up

Export Citation Format

Share Document