基于DEMATEL的非计划性拔管风险因素分析

目的应用决策试验与评价实验室方法(DEMATEL)确定非计划性拔管的关键风险因素,为临床管道管理提供决策依据。方法对49例非计划性拔管不良事件,由管道护理小组现场认证确定19项风险因素;选取35名专家进行2轮函询,以函询结果构建风险因素的直接影响矩阵,运用DEMATEL软件计算综合影响度(Tr)、被影响度(Tc)、中心度(Mi)和原因度(Ri)。结果专家积极性为100%,权威程度0.857,协调系数0.297(P0.05);19项风险因素的Tr为0~2.535,Tc为0~2.321,Mi为0.653~3.891,Ri0的风险因素有10个,Ri0的风险因素有9个。结论基于DEMATEL分析影响非计划性拔管的风险因素,其主要风险因素有操作方法、固定方法、肢体约束、健康教育及高危人群评估,其中操作方法为最关键因素。     

Pile sorting innovations: Exploring gender norms,power and equity in sub-Saharan Africa

Abstract

Understanding gender norms, power and equity is important for developing successful sexual and reproductive health interventions. However, little attention has been given to how to capture the gender ideals and imbalances that inform these relationships in low resource settings. Pile sorting exercises were conducted in four gender-segregated focus groups in Ethiopia and Kenya. Each group received cards illustrated with a man, woman and man and woman together and cards labelled with duties and decisions. Participants discussed and decided together whether men, women or both performed each duty and decision and assigned the cards accordingly. Participants then reflected on and physically manipulated the piles to challenge gender norms, investigate role flexibility and identify agents of social change. Data collected included photographs of the pile sorts and recordings of the discussions. Conducting pile sorting within focus group discussions enabled comparative analyses of gender norms, while enriching data by focusing discussions and encouraging consensus building. Innovative applications facilitated participants' abilities to engage abstract concepts, reflecting on issues of gender norms, power and equity.     

Compellingness: assessing the practical relevance of clinical research results

While the critical appraisal of clinical research has generally focused on aspects of study design and statistical analysis, other features of clinical studies appear to be more important to clinicians for assessing the value of a particular study in the care of particular patients. These features relate to the quality of the knowledge derived from the research, the value of the results to the care of individual patients, and the responsibility of clinicians to be stewards of limited resources. Twelve features of clinical research studies that affect how compelling individual clinicians find the results are proposed and examined here. By better understanding what makes clinical research compelling enough to alter or reinforce clinical practice, clinical researchers can design future studies to better serve the needs of clinicians and patients.     

Physiological basis of preoperative cardiopulmonary exercise testing

The use of cardiopulmonary exercise testing (CPET) is gaining popularity as a preoperative functional assessment tool and a useful adjunct to risk stratification before surgery. Determination of the integrated response of multiple body systems (including the cardiorespiratory and peripheral oxygen delivery systems) to exercise stress, adds important prognostic value to pre-surgical assessment, shared-decision making and postoperative management of the surgical patient. Thorough CPET interpretation is complex but may be assisted by an understanding of basic exercise physiology and its application to the preoperative context.     

Human subjects exploit a cognitive map for credit assignment

An influential reinforcement learning framework proposes that behavior is jointly governed by model-free (MF) and model-based (MB) controllers. The former learns the values of actions directly from past encounters, and the latter exploits a cognitive map of the task to calculate these prospectively. Considerable attention has been paid to how these systems interact during choice, but how and whether knowledge of a cognitive map contributes to the way MF and MB controllers assign credit (i.e., to how they revaluate actions and states following the receipt of an outcome) remains underexplored. Here, we examine such sophisticated credit assignment using a dual-outcome bandit task. We provide evidence that knowledge of a cognitive map influences credit assignment in both MF and MB systems, mediating subtly different aspects of apparent relevance. Specifically, we show MF credit assignment is enhanced for those rewards that are related to a choice, and this contrasted with choice-unrelated rewards that reinforced subsequent choices negatively. This modulation is only possible based on knowledge of task structure. On the other hand, MB credit assignment was boosted for outcomes that impacted on differences in values between offered bandits. We consider mechanistic accounts and the normative status of these findings. We suggest the findings extend the scope and sophistication of cognitive map-based credit assignment during reinforcement learning, with implications for understanding behavioral control.

An extensive body of psychological and neuroscientific literature on dual-system reinforcement learning (RL) indicates that behavior is governed by two distinct systems (1–17)—a rigid, retrospective model-free (MF) system (18, 19) and a flexible, prospective model-based (MB) system (18, 20). Unlike an MF system, which tends to repeat actions with a past history of success, an MB system relies on a cognitive map (CM) (21), that is, a model detailing the structure of a decision-making environment, including how states, actions, observations, and rewards are linked, to predict the impact of action choice on potential future rewards. Recent research highlights competitive and cooperative interactions between these systems, including speed accuracy trade-offs (22), reliability-based arbitration (1, 23), and a plan-to-habit strategy (24), with a focus on a prospective-planning role served by the MB system during choice. Recently, we demonstrated another influence of a CM (and thus, as we described it there, MB processes) in guiding credit assignment (CA) to MF action-values (i.e., affecting how MF values of actions and states are updated as reward-outcomes are received) (25). However, by design, this influence was limited to unraveling the resolution of state uncertainty for MF purposes, leaving broader aspects of the contribution of CM-based processes to CA unexplored.Here, we consider two potential complementary CM-based modulators of CA. Both concern the causal structure of the relationship between options and outcomes. One involves the “relatedness” of actual outcomes to an enacted choice, a retrospective effect of a CM on MF CA. The second involves the “importance” of potential outcomes during the deliberation process preceding a choice, a prospective effect of a CM on MB CA.“Relatedness” arises out of a complexity in assigning credit when information about streams of rewards is provided that depends only partly on the actions taken (unlike situations that involve simple lotteries, for instance, when an action is directly followed by the reward it occasions). An MF system, lacking structural causal knowledge, is disposed to assign credit naively to a choice based on the entire collection of ensuing outcomes, irrespective of whether these outcomes were caused by, or related to, an actual initiating action choice. By contrast, knowledge stored as a CM can guide MF CA to favor action-related outcomes.Take an example of a trader who deliberates purchasing one of two available mutual funds: X, which invests in companies A and B, or Y, which invests in companies A and C. Assume the trader opts for X and then later receives positive information about companies B and D. The trader might assign credit in an MF manner to her/his past action (“buy X”), updating the action’s cached value on the basis that positive consequences followed that choice. However, only one component of those positive consequences (that concerning company B) actually related to the choice of fund X. We propose that MF CA is modulated by a CM such that a change in the action’s value will be affected mostly by information about company B. More generally, relatedness depends on a causal attribution of rewards to actions (26).We consider a second modulator of CA, termed “importance,” as a form of attentional effect. When deliberating between several choice options, and taking into account their prospective outcomes, it is often the case that certain outcomes (which we dub “unimportant”) should not determine choice, as they are common to all choice options. In contrast, other (“important”) outcomes are distinctive to some choice options but not to others, and these should be the main determinants of choice. A CM will contain this type of information and direct attention to the latter alone. We consider the possibility that when the outcomes of the choice are observed, those that garnered more attention at choice are favored in learning.Consider our previous example where information about companies B and D triggers a CA process that leads to positive revaluation of these companies—a process useful for future MB financial decisions related to these companies. We propose this CA process can be biased by CM-based deliberations during choice. Notably, the values of companies B and C were “important” in the trader’s MB deliberation process (choosing a fund), as each is unique to one fund. The values of companies A and D, on the other hand, are less important, as these are either common to both choice options (A) or altogether absent (D). We hypothesize that representations of “important” components in a CM are activated more strongly during choice, leading to them being revalued more when information about choice outcomes are subsequently realized. Thus, ceteris paribus, the increase in the trader’s evaluation of company B will be higher than for company D, given the positive information. This evaluation is then exploited by MB planning processes for future choices.To test these hypotheses, we developed a variant of our previously described dual-outcome bandit task (25). Participants chose between pairs of bandits (i.e., lotteries) that led to different outcomes and received a stream of reward feedback pertaining to choice-related, choice-unrelated, important, and unimportant outcomes. Critically, there are two ways to value bandits in this task. An MF controller treats each bandit holistically, and, as described above, an MB controller predicts the values of the bandits from knowledge of the outcomes to which the bandits lead as provided by a putative CM. This distinction in the structure of evaluations can then be generalized to the apportioning of credit. We consider CA to a bandit to take the form of an MF credit assignment (MFCA; since the MF system makes decisions directly based on these values). Similarly, we consider CA to the outcomes associated with the bandits to be an MB credit assignment (MBCA). To put this another way, the main distinction between MFCA and MBCA in our task is that the former pertains to a revaluation of actions, while the latter pertains to a revaluation of latent causes for these actions (i.e., the ensuing outcomes).In support of our hypothesis that MFCA is guided by a CM, we found evidence that credit for choice-related and -unrelated outcomes is assigned to actions in a different manner. We show information about rewards actually related to chosen actions alone positively impact on the value of those actions. Information about rewards not related to chosen actions, on the other hand, have an opposite effect. Second, we found that MBCA was greater for choice outcomes that were “important” compared to “unimportant” during choice deliberations. We discuss mechanistic and normative accounts of these results.     

Personal Values that Support and Counteract Utilization of a Screening Test for Prostate Cancer

The main aim of the current research was to discover the personal values that may support men's prostate cancer screening decisions in the future. We asked for participants’ past behavior and future behavioral intentions, and also considered their real-life behavior. The sample consisted of 371 men, of which 93 were first-time patients at the Andrology Unit. The results show that Security value was related to past participation, while Achievement, Stimulation, and Traditions counteracted this. Present prostate-testing behavior was related only to higher Security values. Predictors of future behavioral intentions were Security, Self-direction, and Benevolence, which described 21% of the total variability. Considering informed decision-making processes, our results suggest that men who hold Security, Self-direction, and Benevolence values are more likely to participate in office-based initial screening. The study indicates the need to offer office-based initial screening to those age-eligible men whose values do not support participation.