Anomalous Evidence, Confidence Change, and Theory Change.

A novel experimental paradigm that measured theory change and confidence in participants' theories was used in three experiments to test the effects of anomalous evidence. Experiment 1 varied the amount of anomalous evidence to see if "dose size" made incremental changes in confidence toward theory change. Experiment 2 varied whether anomalous evidence was convergent (of multiple types) or replicating (similar finding repeated). Experiment 3 varied whether participants were provided with an alternative theory that explained the anomalous evidence. All experiments showed that participants' confidence changes were commensurate with the amount of anomalous evidence presented, and that larger decreases in confidence predicted theory changes. Convergent evidence and the presentation of an alternative theory led to larger confidence change. Convergent evidence also caused more theory changes. Even when people do not change theories, factors pertinent to the evidence and alternative theories decrease their confidence in their current theory and move them incrementally closer to theory change.

Radiographic Sarcopenia and Self-reported Exhaustion Independently Predict NSQIP Serious Complications After Pancreaticoduodenectomy in Older Adults.

INTRODUCTION: Sarcopenia is linked to poor outcomes after abdominal surgery. We hypothesized that radiographic sarcopenia metrics enhance prediction of complications after pancreaticoduodenectomy (PD) when combined with clinical and frailty data. METHODS: Preoperative geriatric assessments and CT scans of patients undergoing PD were reviewed. Sarcopenia was assessed at L3 using total psoas area index (TPAI) and weighted average Hounsfield units (HU), i.e., estimates of psoas muscle volume and density. Outcomes included 30-day American College of Surgeons National Surgical Quality Improvement Program (NSQIP) serious complications, Clavien-Dindo complications, unplanned intensive care unit (ICU) admission, hospital length of stay (LOS), non-home facility (NHF) discharge, and readmission rates. RESULTS: Low HU score correlated with NSQIP serious complications (r = -0.31, p = 0.0098), Clavien-Dindo complication grade (r = -0.29, p = 0.0183), unplanned ICU admission (r = -0.28, p = 0.0239), and NHF discharge (r = -0.25, p = 0.0426). Controlling for a "base model" of age, body mass index, American Society of Anesthesiologists score, and comorbidity burden, Fried's exhaustion (odds ratio [OR] 4.72 [1.23-17.71], p = 0.021), and HU (OR 0.88 [0.79-0.98], p = 0.024) predicted NSQIP serious complications. Area under the receiver-operator characteristic (AUC) curves demonstrated that the combination of the base model, exhaustion, and HU trended towards improving the prediction of NSQIP serious complications compared with the base model alone (AUC = 0.81 vs. 0.70; p = 0.09). Additionally, when controlling for the base model, TPAI (ß-coefficient = 0.55 [0.10-1.01], p = 0.018) and exhaustion (ß-coefficient = 2.47 [0.75-4.20], p = 0.005) predicted LOS and exhaustion (OR 4.14 [1.48-11.6], p = 0.007) predicted readmissions. CONCLUSIONS: When combined with clinical and frailty assessments, radiographic sarcopenia metrics enhance prediction of post-PD outcomes.

African American men significantly underestimate their risk of having prostate cancer at the time of biopsy.

BACKGROUND: Guidelines for prostate cancer (PCa) screening recommend physicians to have an informational discussion with patients. At the time of biopsy, patients should be informed of their heightened PCa risk, particularly African Americans (AA) who have significantly higher diagnostic and mortality risk. We tested predictors of patients' estimation of their likelihood of having PCa at the time of biopsy. METHODS: A convenience sample of AA (n = 207) and white (n = 271) biopsy patients was surveyed at the time of prostate biopsy. Participants gave likelihood estimations of having PCa and data on their socio-demographics, health, clinical status, and general and PCa-specific anxiety. Binary logistic regressions tested for predictors of the patients' estimations and biopsy results. RESULTS: Fifty-one percent of AA men answered that they had a '0%' likelihood of having PCa versus 19% of whites, whereas 57% of AA men had abnormal biopsies compared with 42% of whites. In logistic regressions, predictors of patient answers of 0% chance of PCa were AA ethnicity (OR = 4.50; p < 0.001), lower cancer-specific anxiety (OR = 0.93; p < 0.01), less education (OR = 2.38; p < 0.05), and less urinary disturbance (OR = 0.70; p < .05). In a second regression, AA patients trended towards higher positive biopsy rates (OR = 1.43; p = 0.17). CONCLUSIONS: At biopsy, AA more often estimated their likelihood of PCa as 0%, despite higher risks. Reasons for these low estimates and their potential contribution to poor treatment outcomes of AA patients require further investigation.

Risk as feelings in the effect of patient outcomes on physicians' future treatment decisions: a randomized trial and manipulation validation.

The present study tested predictions derived from the Risk as Feelings hypothesis about the effects of prior patients' negative treatment outcomes on physicians' subsequent treatment decisions. Two experiments at The University of Chicago, U.S.A., utilized a computer simulation of an abdominal aortic aneurysm (AAA) patient with enhanced realism to present participants with one of three experimental conditions: AAA rupture causing a watchful waiting death (WWD), perioperative death (PD), or a successful operation (SO), as well as the statistical treatment guidelines for AAA. Experiment 1 tested effects of these simulated outcomes on (n = 76) laboratory participants' (university student sample) self-reported emotions, and their ratings of valence and arousal of the AAA rupture simulation and other emotion-inducing picture stimuli. Experiment 2 tested two hypotheses: 1) that experiencing a patient WWD in the practice trial's experimental condition would lead physicians to choose surgery earlier, and 2) experiencing a patient PD would lead physicians to choose surgery later with the next patient. Experiment 2 presented (n = 132) physicians (surgeons and geriatricians) with the same experimental manipulation and a second simulated AAA patient. Physicians then chose to either go to surgery or continue watchful waiting. The results of Experiment 1 demonstrated that the WWD experimental condition significantly increased anxiety, and was rated similarly to other negative and arousing pictures. The results of Experiment 2 demonstrated that, after controlling for demographics, baseline anxiety, intolerance for uncertainty, risk attitudes, and the influence of simulation characteristics, the WWD experimental condition significantly expedited decisions to choose surgery for the next patient. The results support the Risk as Feelings hypothesis on physicians' treatment decisions in a realistic AAA patient computer simulation. Bad outcomes affected emotions and decisions, even with statistical AAA rupture risk guidance present. These results suggest that bad patient outcomes cause physicians to experience anxiety and regret that influences their subsequent treatment decision-making for the next patient.

Vivid bad outcome influences the decisions of older adults about treatment timing: a randomized field experiment with an abdominal aortic aneurysm analog.

In balancing the risk of rupture from an asymptomatic abdominal aortic aneurysm (AAA) against the risk of perioperative mortality, data-based guidelines recommend surgical repair when the AAA diameter reaches 5.5 cm, whereas smaller AAAs should be followed with periodic surveillance. Previous work with vascular surgeon subjects and a computer-based AAA analog simulation showed that, even when constantly updated with the relevant statistics, experiencing a prior bad watchful waiting outcome shortened the time until they made the decision to operate. Using the same simulation, this field experiment enrolled healthy older volunteers (n = 107). Participants were randomly assigned to experience either a bad outcome demonstration with an expanding balloon that bursts (experimental) or an expanding, nonbursting balloon (control). Participants then made decisions about how many times to allow the balloon to expand before opting-out of the simulation. The main outcome measure was the amount of time participants continued watchful waiting before opting-out. A Cox-regression analysis assessed the likelihood of opting-out after each expansion while controlling for censoring and important covariates, including baseline anxiety, uncertainty attitudes, and risk preferences. The bad outcome demonstration group ended the simulation significantly earlier than did the control subjects (Hazard ratio: 1.98; 95% CI: 1.05-3.74). These results extend previous findings from vascular surgeons to older adults at higher risk for AAA. The preceding bad outcome influenced subsequent decisions, even when statistical risk information was readily available. The influence of recent experience on medical decision making by patients with life-threatening conditions may be under-appreciated.