Tests of consequence monotonicity in decision making under uncertainty

Consequence monotonicity means that if 2 gambles differ only in 1 consequence, the one having the better consequence is preferred. This property has been sustained in direct comparisons but apparently fails for some gamble pairs when they are ordered in terms of judged monetary certainty equivalents. In Experiments 1 and 3 a judgment procedure was compared with 2 variants of a choice procedure. Slightly fewer nonmonotonicities were found in one of the choice procedures, and, overall, fewer violations occurred than in previous studies. Experiments 2 and 3 showed that the difference was not due to procedural or stimulus presentation differences. Experiment 4 tested a noise model that suggested that the observed violations were due primarily to noise in estimating certainty equivalents, and so, despite some proportion of observed violations, consequence monotonicity cannot be rejected in that case.     

Four techniques of group decision making under uncertainty.

4 techniques of group decision-making—authoritarian, leader suggestion, census, and chairman—under risk and uncertainty were compared using a survival situation with 45 aircrews. "1. In a conflict situation, when a group discussion method… is involved, the members' reactions to the alternatives are relatively undifferentiated in contrast to the condition in which the leader alone makes the decision… . 2… . the groups appear to be least favorably disposed toward the authoritarian technique of decision-making… . 3. When the decision-making procedure is group centered the group reaches a decision involving greater personal risk to the members." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion regulation and decision making under risk and uncertainty.

It is well established that emotion plays a key role in human social and economic decision making. The recent literature on emotion regulation (ER), however, highlights that humans typically make efforts to control emotion experiences. This leaves open the possibility that decision effects previously attributed to acute emotion may be a consequence of acute ER strategies such as cognitive reappraisal and expressive suppression. In Study 1, we manipulated ER of laboratory-induced fear and disgust, and found that the cognitive reappraisal of these negative emotions promotes risky decisions (reduces risk aversion) in the Balloon Analogue Risk Task and is associated with increased performance in the prehunch/hunch period of the Iowa Gambling Task. In Study 2, we found that naturally occurring negative emotions also increase risk aversion in Balloon Analogue Risk Task, but the incidental use of cognitive reappraisal of emotions impedes this effect. We offer evidence that the increased effectiveness of cognitive reappraisal in reducing the experience of emotions underlies its beneficial effects on decision making. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formalized decision support for cardiovascular intensive care

The massive volume of hemodynamic data routinely available within the Cardiovascular Intensive Care Unit (CVICU) can adversely affect the quality, relevance, and timing of hemodynamic management decisions on patients after cardiac surgery. Yet, at the same time, the lack of appropriate treatment-outcome data and access to prior CV case histories deprives the clinician of any opportunity to improve personal decision-making skill and assess the effectiveness of various treatment methods. This paper presents a formalized decision-support model for CVICU that incorporates expert and quantitative knowledge, as well as prior outcome and case experience to augment the clinician's decision-making capability. This includes the use of optimal hemodynamic patterns derived from outcome analysis as therapy goals, expert rules and trend analysis to interpret incoming data, standardized protocols based on predefined hemodynamic patterns from clinical cases, and access to the database for similar case comparison. Most importantly, the model suggests an integrated approach where the clinical database not only is a documentation source for the patient, but also can serve as an outcome research database where clinical experience can be formalized and combined with expert knowledge to influence future therapy decisions. At present, a prototype is being developed at the CVICU of the University of Alberta Hospitals on a Unix platform using ART-IM, C and Ingres. Once implemented, the prototype will be evaluated on a small group of CV patients for its effectiveness and acceptability to clinicians.     

Determinants of clinical decision making in primary care: opinion of physicians

The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by 32P-postlabelling DNA analysis. The results of quantitative 32P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3-6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The 32P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by 32P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/microg DNA per mg oil product. The in vivo 32P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with 32P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of total PAC contents or 3 6 ring PAC contents of the oil products.     

Democracy under uncertainty: The wisdom of crowds and the free-rider problem in group decision making.

We introduce a game theory model of individual decisions to cooperate by contributing personal resources to group decisions versus by free riding on the contributions of other members. In contrast to most public-goods games that assume group returns are linear in individual contributions, the present model assumes decreasing marginal group production as a function of aggregate individual contributions. This diminishing marginal returns assumption is more realistic and generates starkly different predictions compared to the linear model. One important implication is that, under most conditions, there exist equilibria where some, but not all, members of a group contribute, even with completely self-interested motives. An agent-based simulation confirmed the individual and group advantages of the equilibria in which behavioral asymmetry emerges from a game structure that is a priori perfectly symmetric for all agents (all agents have the same payoff function and action space but take different actions in equilibria). A behavioral experiment demonstrated that cooperators and free riders coexist in a stable manner in groups performing with the nonlinear production function. A collateral result demonstrated that, compared to a dictatorial decision scheme guided by the best member in a group, the majority/plurality decision rules can pool information effectively and produce greater individual net welfare at equilibrium, even if free riding is not sanctioned. This is an original proof that cooperation in ad hoc decision-making groups can be understood in terms of self-interested motivations and that, despite the free-rider problem, majority/plurality decision rules can function robustly as simple, efficient social decision heuristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Primary care physicians' medical decision making for late-life depression

OBJECTIVE: To describe primary care physicians' clinical decision making regarding late-life depression. DESIGN: Longitudinal collection of data regarding physicians' clinical assessments and the volume and content of patients' ambulatory visits as part of a randomized clinical trial of a physician-targeted intervention to improve the treatment of late-life depression. SETTING: Academic primary care group practice. PATIENTS/PARTICIPANTS: One-hundred and eleven primary care physicians who completed a structured questionnaire to describe their clinical assessments immediately following their evaluations of 222 elderly patients who had reported symptoms of depression on screening questionnaires. INTERVENTIONS: Intervention physicians were provided with their patient's score on the Hamilton Depression rating scale (HAM-D) and patient-specific treatment recommendations prior to completing the questionnaire regarding their clinical assessment. MAIN RESULTS: Those physicians not provided HAM-D scores were just as likely to rate their patients as depressed, as determined by specific query of these physicians regarding their clinical assessments. A physician's clinical rating of likely depression did not consistently result in the formulation of treatment intentions or actions. Treatment intentions and actions were facilitated by provision of treatment algorithms, but treatment was received by fewer than half of the patients whom physicians intended to treat. Barriers to treatment appear to include both physician and patient doubts about treatment benefits. CONCLUSIONS: Lack of recognition of depressive symptoms did not appear to be the primary barrier to treatment. Recognition of symptoms and access to treatment algorithms did not consistently result in progression to subsequent stages in treatment decision making. More research is needed to determine how patients and physicians weigh the potential risks and benefits of treatment and how accurately they make these judgments.     

Shared decision making in critical care: a clinical reality and an ethical necessity

The aim of this study was to determine the etiology, associated anomalies and outcome of fetuses with postural deformities and contractures of the upper extremities detected sonographically. Fifty-four fetuses with sonographically detected postural anomalies of the upper extremities were identified from our database. Sonographic findings and associated anomalies were tabulated on the basis of the original sonogram. Perinatal follow-up and/or karyotype were available in 52 cases from a review of the maternal and newborn medical records and pathology reports. Of the 52 fetuses with sonographically detected anomalies of the upper extremities, 44 (85%) were non-survivors and eight (15%) were survivors. Forty-three fetuses had associated sonographic abnormalities. Karyotyping performed in 44 cases revealed 26 cases (59%) of aneuploidy, with trisomy 18 accounting for 23/26 (88%). In the setting of a normal karyotype, a variety of genetic disorders were found, including syndromes involving the fetal dyskinesia/akinesia sequence. Disturbances in amniotic fluid occurred in 48% of the cases (24 fetuses with polyhydramnios and one with oligohydramnios). In conclusion, the sonographic detection of postural abnormalities of the upper extremities carries a guarded prognosis, with survival in 15% of fetuses and a high incidence of chromosomal defects.     

Admitting paediatric trauma patients to rehabilitation following acute care: decision making practices in the USA and Australia

Paediatric patient access to rehabilitation services following trauma has significant long-term implications for clients, their families and the community. The aim of this research was to examine and compare the process by which patients are discharged from acute care and enter rehabilitation in the USA and Australia. The subjects were 31 American and 29 Australian discharge and rehabilitation admission coordinators. Subjects were surveyed about how they currently make trauma to rehabilitation referrals for children. Clinicians in both countries considered the severity of a child's injury and their social situation the most important factors when determining placement for a child. However, there were differences between Australian and US respondents in terms of how important they considered the factor 'medical coverage'. In addition, it was found that clinicians are not consistently using both standardized assessments and formal guidelines to assist them to determine which children should receive rehabilitation following acute care. Benefits of this research include a greater understanding of clinician discharge and admission decision making, and the equity of such decisions. However, further research is required on the influence of payment systems on access to paediatric rehabilitation.     

Program evaluation: resource for decision making

Formal program evaluation is an important resource for health care decision making. It is necessary in situations where traditional organizational evaluative capabilities an no longer meet the requirements of the job at hand.     

Patient values: the guide to medical decision making

Physicians are increasingly challenged by issues surrounding medical decision-making for hospitalized patients. Advance directives express a patient's preferences regarding end-of-life care; when available, they should be used to guide medical treatment. Patients who lack decision-making capacity require special consideration to ensure maximal patient participation with appropriate surrogate involvement. An ethics committee consultation may be especially helpful to resolve conflicts that may arise regarding medical treatments. Physicians play a vital role in promoting earlier patient-physician discussions about end-of-life care preferences, increased completion of advance directives, and ongoing education for physicians to improve communication skills.     

Linear models in decision making.

A review of the literature indicates that linear models are frequently used in situations in which decisions are made on the basis of multiple codable inputs. These models are sometimes used (a) normatively to aid the decision maker, (b) as a contrast with the decision maker in the clinical vs statistical controversy, (c) to represent the decision maker "paramorphically" and (d) to "bootstrap" the decision maker by replacing him with his representation. Examination of the contexts in which linear models have been successfully employed indicates that the contexts have the following structural characteristics in common: each input variable has a conditionally monotone relationship with the output; there is error of measurement; and deviations from optimal weighting do not make much practical difference. These characteristics ensure the success of linear models, which are so appropriate in such contexts that random linear models (i.e., models whose weights are randomly chosen except for sign) may perform quite well. 4 examples involving the prediction of such codable output variables as GPA and psychiatric diagnosis are analyzed in detail. In all 4 examples, random linear models yield predictions that are superior to those of human judges. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal horizons in decision making.

The perception of duration is crucial when we make choices between immediate and delayed rewards. Immediate rewards are valued more than the same rewards if they are delayed. Preferences for earlier rewards become even stronger when the reward can be received within a subjectively proximate time frame. A “rational” decision to wait for a delayed reward may be overruled by an “impulsive” choice when the option for the closer reward falls within this proximate time range. Based on findings on circadian and circannual physiological rhythms, we suggest that there are 2 time units that are both biologically and culturally determined and have an impact on human experience and behavior: the day and the year. We highlight results of a neuroimaging study showing that rewards with delays up to 1 year are discounted differently than reward delays longer than 1 year. This duration-dependent discounting is associated with specific brain activation in the striatum. We present various conceptualizations of subjective time incorporated in parametric models of intertemporal decisions that may lead to a better understanding of human choice behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Annual league tables of mortality in neonatal intensive care units: longitudinal study. International Neonatal Network and the Scottish Neonatal Consultants and Nurses Collaborative Study Group

OBJECTIVE: To assess whether crude league tables of mortality and league tables of risk adjusted mortality accurately reflect the performance of hospitals. DESIGN: Longitudinal study of mortality occurring in hospital. SETTING: 9 neonatal intensive care units in the United Kingdom. SUBJECTS: 2671 very low birth weight or preterm infants admitted to neonatal intensive care units between 1988 and 1994. MAIN OUTCOME MEASURES: Crude hospital mortality and hospital mortality adjusted using the clinical risk index for babies (CRIB) score. RESULTS: Hospitals had wide and overlapping confidence intervals when ranked by mortality in annual league tables; this made it impossible to discriminate between hospitals reliably. In most years there was no significant difference between hospitals, only random variation. The apparent performance of individual hospitals fluctuated substantially from year to year. CONCLUSIONS: Annual league tables are not reliable indicators of performance or best practice; they do not reflect consistent differences between hospitals. Any action prompted by the annual league tables would have been equally likely to have been beneficial, detrimental, or irrelevant. Mortality should be compared between groups of hospitals using specific criteria-such as differences in the volume of patients, staffing policy, training of staff, or aspects of clinical practice-after adjusting for risk. This will produce more reliable estimates with narrower confidence intervals, and more reliable and rapid conclusions.     

Ignorance- versus evidence-based decision making: A decision time analysis of the recognition heuristic.

According to part of the adaptive toolbox notion of decision making known as the recognition heuristic (RH), the decision process in comparative judgments—and its duration—is determined by whether recognition discriminates between objects. By contrast, some recently proposed alternative models predict that choices largely depend on the amount of evidence speaking for each of the objects and that decision times thus depend on the evidential difference between objects, or the degree of conflict between options. This article presents 3 experiments that tested predictions derived from the RH against those from alternative models. All experiments used naturally recognized objects without teaching participants any information and thus provided optimal conditions for application of the RH. However, results supported the alternative, evidence-based models and often conflicted with the RH. Recognition was not the key determinant of decision times, whereas differences between objects with respect to (both positive and negative) evidence predicted effects well. In sum, alternative models that allow for the integration of different pieces of information may well provide a better account of comparative judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)