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PubMed1981

On the relativity and uncertainty of electromagnetic energy measurement at a superconductive boundary. Application to perception of weak magnetic fields by living systems.

From quantum mechanical and relativity principles applied to an observer using a bounded superconductive detector, any magnetic or electric field, which superficially may appear steady and homogeneous, should be perceived to have a wavelength and frequency which are functions of the size of the detector as well as of the energy density of the field. From the Heisenberg uncertainty principle, equations are derived for the uncertainties of measurement of field energy and of detector size as imposed by the principles of quantum mechanics, even if the instruments of measurement are perfect. If energy density is sufficiently low and/or size of detector is sufficiently small, then numerical values and geometries of the fields become unmeasurable by any experimental method but topological properties of the system may still be measurable. A method for estimation of size of superconductive microregions in materials or in living systems is derived. It is calculated that if superconductive microdetectors exist in living systems capable of detection of 0.1 to 1.0 gauss magnetic fields, then minimum superconductive detector diameters of 7.9 and 2.6 microns respectively are required, and these magnetic fields will have perceived effects equivalent to wavelengths of 7.9 and 2.6 microns respectively (the infrared region of light). The estimated detector sizes are comparable with the sizes of mitochondria, melanin granules, and retinal rods.

Animals↗
PubMed1980

The National Head and Spinal Cord Injury Survey: assessment of some uncertainties affecting the findings.

The estimates from the National Head and Spinal Cord Injury Survey, like estimates from other studies, are subject to many uncertainties and must be viewed as conditional. This article provides a list of conditions that affect estimates from studies. For this survey, two structural limitations are discussed. The first is the exclusion from the survey of persons who were fatally injured and did not receive hospital inpatient care (for instance, individuals who were dead on arrival at the hospital). The second is the exclusion from the survey of persons who were injured before 1970. Also, uncertainties in the data of the survey due to nonresponse and variability between data collectors are discussed.

Craniocerebral Trauma↗
PubMed1994

The Uncertainty Stress Scale: its development and psychometric properties.

This paper describes the development and testing of a new scale--The Uncertainty Stress Scale--which measures uncertainty in illness-related situations, and the stress, threat, and positive feelings generated from the uncertain state. The theoretical and empirical basis of the scale is presented. Evidence which supports the scale's reliability and its content, concurrent, and construct validity is presented from several studies of people experiencing acute and chronic medical conditions. Descriptions and rationales for revisions are described.

Adult↗
PubMed1994

Uncertainty: strategies for patients with brain tumor and their family.

Patients diagnosed with a brain tumor and their families are faced with uncertainties that result from the progression of the disease and treatment regimen. Many strategies can be used to help patients and families deal with these uncertainties. A case report is used to illustrate how changing needs of a patient and family were met by using different strategies.

Adaptation, Psychological↗
PubMed1993

Medical decisions under uncertainty.

The court applies the criteria of the reasonable doctor and common practice in order to consider the behaviour of a defendant physician. The meaning of our demand that the doctor expects that his or her acts or omissions will bring about certain implications is that, according to the present circumstances and subject to the limited knowledge of the common practice, the course of certain events or situations in the future may be assumed in spite of the fog of uncertainty which surrounds us. The miracles and wonders of creation are concealed from us, and we are not aware of the way and the nature of our bodily functioning. Therefore, there seems to be no way to avoid mistakes, because in several cases the correct diagnosis cannot be determined even with the most advanced application of all information available. Doctors find it difficult to admit that they grope in the dark. They wish to form clear and accurate diagnoses for their patients. The fact that their profession is faced with innumerable and unavoidable risks and mistakes is hard to swallow, and many of them claim that in their everyday work this does not happen. They should not content themselves by changing their style. A radical metamorphosis is needed. They should not be tempted to formulate their diagnoses in 'neutral' statements in order to be on the safe side. Uncertainty should be accepted and acknowledged by the profession and by the public at large as a human phenomenon, as an integral part of any human decision, and as a clear characteristic of any legal or medical diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMedDate not supplied

Methodology for a medical expert system on fuzzy analog ganglionar lattices. Non-approximate reasoning with multiple antecendents of different relative importance and limited uncertainty.

This work presents an Expert System based on fuzzy analog ganglionar lattices. Its reasoning scheme is designed analogously to the expert's mental organization and it is realized on an (analog) operator called the ganglionar lattice. It is a connectionist system that uses the medical knowledge to define its architecture. The operator evokes some similarities to higher order neural networks and performs as the knowledge base and inference engine of the expert system, in a unified manner. A main feature of this operator is that it exhibits the variables corresponding to all intermediate concepts identified by the expert; this characteristic is shown to be most valuable for assessing, explicating and prospecting in medical applications. Further, it is capable of (i) evaluating a consequent for a variety of non-approximate reasonings with multiple antecendents of different relative importance under limited uncertainty; (ii) explicating the conclusions at different levels of abstraction to suit the user; and (iii) prospecting for the best 'a priori' sequence of unevaluated antecedents, from which to choose following tests. These procedures are based on the objective criterion of the consequent's uncertainty decrease (entropy). All results are produced in numerical form and may be translated into restricted natural language. A simple example of this technology is fully developed. Finally the method's potentials are discussed for future applications.

Artificial Intelligence↗
PubMed1997

Uncertainty considerations in group decisions: staffing and ratesetting in a health promotion center.

There are a variety of methods for including risk or uncertainty in Group Decision Support Systems (GDSS). Monte Carlo simulation is one method. An application of Monte Carlo simulation in Group Decisions and GDSS for diversification of services is presented in this paper. Specifically, the uncertainty associated with the finances of a Health Promotion Center are evaluated for staffing and rate setting. The distributions of outcome variables are used in decision rules.

Ambulatory Care Facilities↗
PubMed1997

Uncertainty in acute illness.

In this chapter, the research on uncertainty in acute illness is reviewed and critiqued. Both qualitative and quantitative studies are included. The review considers the cause and consequences of uncertainty from research on adults and from research on parents of acutely ill children.

Acute Disease↗
PubMed1998

Human variability and noncancer risk assessment--an analysis of the default uncertainty factor.

A 10-fold uncertainty factor is used for noncancer risk assessments to allow for possible interindividual differences between humans in the fate of the chemical in the body (kinetics) and target organ sensitivity (dynamics). Analysis of a database on the variability in each of these aspects is consistent with an even subdivision of the 10-fold factor into 10(0.5) (3.16) for kinetics and 10(0.5) (3.16) for dynamics. Analysis of the number of subjects in a normally and log-normally distributed population which would not be covered by factors of 3.16 supports this subdivision and also the use of a 10-fold factor to allow for both aspects. Analysis of kinetic data for subgroups of the population indicates that the standard default value of 3.16 for kinetics will not be adequate for all routes of elimination and all groups of the population. A scheme is proposed which would allow the selection of appropriate default uncertainty factors based on knowledge of the biological fate and effects of the chemical under review.

Adolescent↗
PubMed2005

Uncertainty of measurement: approaches and open problems.

Despite of exhaustive literature information, analysts are still fronting serious problems in estimating the uncertainty of measurement (UOM), mainly because of the intrinsic difficulties in choosing an appropriate approach and/or of an inadequate background in statistics and metrology fundamentals. Sometimes, additional problems, at present under debate, make their efforts even more stressful. In this paper, attention is mainly paid to intra-laboratory estimation of UOM, the most frequent situation. After a short re-examination of the existing UOM approaches, some applicative problems are discussed in the light of the most representative literature information.

Reproducibility of Results↗
PubMed2005

Risk aversion and uncertainty in cost-effectiveness analysis: the expected-utility, moment-generating function approach.

The availability of patient-level data from clinical trials has spurred a lot of interest in developing methods for quantifying and presenting uncertainty in cost-effectiveness analysis (CEA). Although the majority has focused on developing methods for using sample data to estimate a confidence interval for an incremental cost-effectiveness ratio (ICER), a small strand of the literature has emphasized the importance of incorporating risk preferences and the trade-off between the mean and the variance of returns to investment in health and medicine (mean-variance analysis). This paper shows how the exponential utility-moment-generating function approach is a natural extension to this branch of the literature for modelling choices from healthcare interventions with uncertain costs and effects. The paper assumes an exponential utility function, which implies constant absolute risk aversion, and is based on the fact that the expected value of this function results in a convenient expression that depends only on the moment-generating function of the random variables. The mean-variance approach is shown to be a special case of this more general framework. The paper characterizes the solution to the resource allocation problem using standard optimization techniques and derives the summary measure researchers need to estimate for each programme, when the assumption of risk neutrality does not hold, and compares it to the standard incremental cost-effectiveness ratio. The importance of choosing the correct distribution of costs and effects and the issues related to estimation of the parameters of the distribution are also discussed. An empirical example to illustrate the methods and concepts is provided.

Cost-Benefit Analysis↗
PubMed2007

'What does it mean?' Uncertainty, trust and communication following treatment for pre-cancerous cervical abnormalities.

The early detection of pre-cancerous cervical conditions has risen dramatically, prompting more in-depth investigations regarding psychological implications inherent within the diagnosis and treatment of this condition. This study aimed to identify factors that influence women's experience of diagnosis and treatment of cervical abnormalities and factors that facilitate positive adjustment. Using a semi-structured telephone interview, we interviewed 21 women (age 24-54) treated at a colposcopy clinic. Systematic recruitment of women with varying degrees of cervical abnormality (CIN 1-3) and time since treatment was undertaken to ensure representation of all relevant experiences and allow the identification of long-term factors. Coding of audio-taped, transcribed interviews and searching for themes was achieved by using NUD*IST software. The results identified uncertainty, trust and communication as the key factors for women following diagnosis and treatment. The primary concern following diagnosis was related to cancer but changed to a more prominent concern with future reproductive issues in the post-treatment period. The majority of women acknowledged the importance of the doctor's empathic communication style. These findings have important implications for future studies and clinical practice.

Adaptation, Psychological↗
PubMed1992

Coping with ambiguity and uncertainty in patient-physician relationships: II. Traditio argumentum respectus.

A methodology of argumentation and a perspective of incredulity are essential ingredients of all intellectual endeavor, including that associated with the art and science of medical care. Traditio argumentum respectus (tradition of respectful argumentation) as a principled system of assessing the validity of beliefs, opinions, perceptions, data, and knowledge, is worthy of practice and perpetuation, because assessments of validity are susceptible to incompleteness, incorrectness, and misinterpretation. Since the latter may lead to ambiguity, uncertainty, anxiety, and animosity among the individuals (patients and physicians) involved in such dialogue, objective analyses and criteria are desirable. A tradition of respectful argumentation is a means to this end -- to maximize objectivity and minimize subjectivity as part of decision-making processes and to preserve the integrity of the participants in a patient-physician relationship. During such discourse one must always be cognizant of fallacious arguments -- material, verbal, and formal fallacies -- since they compromise the validity of assertions. This essay summarizes a classification of fallacious arguments, by definition and by example, predicated upon the intellectual tradition of Occidental Society; and advocates a tradition of respectful argumentation to nullify them.

Communication↗
PubMed1992

Coping with ambiguity and uncertainty in patient-physician relationships: I. Leadership of a physician.

A patient-physician relationship provides a milieu for a patient to achieve healing, solace, and reintegration of personhood. A patient's primary physician assumes a leadership role in that regard, coordinating and facilitating a regimen of analysis and therapy. The quality, quantity, and rapidity of technological advancements in the delivery of medical care, render any individual physician incomplete in terms of his ability to provide total care. Consequently, a succession of professional and paraprofessional personnel must be involved to maximize the care rendered. Nevertheless, a patient's primary physician must fulfill a leadership role as he coordinates consultations and interprets the data they provide, placing it in the appropriate situational context for his patient as part of a collective and mutual decision-making process. A patient's primary physician must be acknowledged to possess the power and authority to effect the care provided, as he must also accept the accountability, duty, obligation, and responsibility for the result of that care. By these means ambiguity and uncertainty are mitigated.

Delivery of Health Care↗
PubMed2006

Assessing domains of uncertainty in critical Web-based healthcare communities.

Search engines and Web-based directories play a central role in facilitating access to online health information. In this environment consumers often find and act upon health information of variable quality, with little input from health professionals. As an added concern, when consumers access health information on the Web via a search engine they often fail to discuss the information with a healthcare provider, especially in areas of perceived medical uncertainty. For many health consumers, the Internet may be the primary (or even sole) source of health information, especially where consumers lack access to, or trust in, trained providers. To date the corresponding role of search engine technology use and efficacy has received relatively little attention, however. This study serves as an exploratory technology assessment that explains the application of keyword effectiveness indexing (KEI) analysis in estimating the ability of commercial search engines to return relevant results for healthcare consumers. Findings suggest that KEI can serve as a useful health search profiling tool, though its applicability may vary across domains.

Community Health Services↗
PubMed2007

Evaluation of uncertainty parameters estimated by different population PK software and methods.

The uncertainty associated with parameter estimations is essential for population model building, evaluation, and simulation. Summarized by the standard error (SE), its estimation is sometimes questionable. Herein, we evaluate SEs provided by different non linear mixed-effect estimation methods associated with their estimation performances. Methods based on maximum likelihood (FO and FOCE in NONMEM, nlme in Splus, and SAEM in MONOLIX) and Bayesian theory (WinBUGS) were evaluated on datasets obtained by simulations of a one-compartment PK model using 9 different designs. Bootstrap techniques were applied to FO, FOCE, and nlme. We compared SE estimations, parameter estimations, convergence, and computation time. Regarding SE estimations, methods provided concordant results for fixed effects. On random effects, SAEM and WinBUGS, tended respectively to under or over-estimate them. With sparse data, FO provided biased estimations of SE and discordant results between bootstrapped and original datasets. Regarding parameter estimations, FO showed a systematic bias on fixed and random effects. WinBUGS provided biased estimations, but only with sparse data. SAEM and WinBUGS converged systematically while FOCE failed in half of the cases. Applying bootstrap with FOCE yielded CPU times too large for routine application and bootstrap with nlme resulted in frequent crashes. In conclusion, FO provided bias on parameter estimations and on SE estimations of random effects. Methods like FOCE provided unbiased results but convergence was the biggest issue. Bootstrap did not improve SEs for FOCE methods, except when confidence interval of random effects is needed. WinBUGS gave consistent results but required long computation times. SAEM was in-between, showing few under-estimated SE but unbiased parameter estimations.

Bayes Theorem↗
PubMed2026

Navigating uncertainties and evidence gaps in adjuvant therapy for premenopausal women with HR+/HER2- breast cancer.

Premenopausal women with hormone receptor-positive (HR+)/HER2-negative early breast cancer represent a clinically distinct population, characterized by more aggressive tumor biology, unique survivorship concerns, and complex treatment decision-making. Although evidence from dedicated trials and subgroup analyses is available, management remains challenging because data are heterogeneous, evolving, and often extrapolated from broader populations that include predominantly postmenopausal women. Adjuvant endocrine therapy, with the addition of CDK4/6 inhibitors in selected higher-risk patients, remains the cornerstone of treatment; however major uncertainties persist regarding the optimal use of ovarian function suppression, the interpretation of genomic assays to inform chemotherapy decisions, the selection of candidates for extended endocrine therapy, and the management of adherence, treatment-related toxicities, pregnancy-related issues, and survivorship concerns. Here, we synthesize current evidence across these domains and propose a pragmatic clinical framework to support individualized treatment strategies and optimize care for this population in the contemporary therapeutic landscape.

HR+/HER2- early breast cancer↗
PubMed2006

Animal studies of amygdala function in fear and uncertainty: relevance to human research.

This article reviews research in both animals and humans on the considerable progress made in elucidating a brain circuitry of fear, particularly the importance of the amygdala in fear conditioning. While there is considerable agreement about the participation of the amygdala in fear in both animals and humans, there are several issues about the function of the amygdala raised by the human research that have not been addressed by or may be answered by animal research. Three of these are addressed in this article: (1) is the amygdala involved in or necessary for both fear learning and unconditioned fear? (2) Does the amygdala code for intensity of fear? (3) Is the amygdala preferentially involved in fear, or is it also activated when there are no overt fear or aversive stimuli, but where the situation can be described as uncertain? We present evidence indicating that the rodent amygdala is involved in some types of fear (conditioned fear), but not all types (unconditioned fear), and may therefore have significance for a differential neurobiology of certain anxiety disorders in humans. Further, similar to the human amygdala, the rodent amygdala responds to varying intensities of aversive stimulation. Finally, it is suggested that, similar to humans, the rodent amygdala is involved in the evaluation of uncertainty. We conclude that progress on elucidating the role of the amygdala in fear is facilitated by corroboration of findings from both animal and human research.

Amygdala↗