INVESTIGATING RACIAL BIAS IN PERCEPTIONS OF FREE WILL

The overarching goal of this study was to examine whether perceptions of others’ free will would differ depending on perceiver race as well as target race. The current study proposed that such a racial bias may be one mechanism by which racial disparities in medical treatment recommendations arise. By bridging findings from four different lines of research (i.e., the literatures on racial health and medical treatment disparities, racial bias, free will beliefs, and social identity), it was hypothesized that: (1) participants would perceive greater amounts of free will for a hypothetical racial ingroup patient than an outgroup patient; (2) such effect would be moderated by participant racial identity and/or racial bias, such that greater racial identity and/or ingroup racial bias would result in greater differences in racial ingroup vs. racial outgroup members’ free will; and (3) greater perception of the patient free will would indirectly affect treatment recommendation for the patient through increased perceived patient self-control. In order to test these hypotheses, the study used a 2 (Participant race: Black vs. White) x 2 (Target race: Black vs. White) x Continuous (Racial Identity/Racial Attitudes) between-subjects design, in which target race was manipulated experimentally. The results indicated that Black participants’ perceptions of patient free will was moderated by both racial identity and racial bias. Specifically, those who weakly identified with their racial group perceived a greater amount of free will in the White target patient than the Black target patient. Also, Black participants who displayed pro-White racial bias, a greater amount of free in the White target patient than the Black target patient. These moderating effects of racial identity/racial bias were not found for the White participants. Also, patient free will had an indirect effect on treatment recommendation by way of perceived patient self-control, such that perceived free positively predicted the more rigorous of two treatments. Limitations of the current research include the undergraduate college student sample, the use of a general measure of racial identity, and the use of the old IAT algorithm. Future work should examine empirically whether findings from the present study can be generalized to provider samples

Investigating the Potential Causal Relationship Between Free Will Belief and Well-Being

This multi-study dissertation had four primary aims. My first was to add to the evidence base indicating a positive association between free will belief (FWB) and subjective well-being (SWB). My second aim was to develop a measure to assess the FWB theme referred to as the principle of alternate possibilities (PAP). To achieve the first two aims, I conducted two cross-sectional studies to further establish the FWB-SWB association and start the development and assessment of a new PAP FWB measure. In the first study (N=995), I hypothesized that an EFA of the new PAP items would produce at least a single factor structure and that FWB would be a positive predictor of SWB. Study 1 was successful, the EFA extracted a single PAP factor with 10 items and FWB was shown to positively predict SWB. The second study (N=760) was an exact replication of the first. Study 2 was also successful, replicating the single factor structure for the preliminary 10-item PAP measure as well as the positive association between FWB and SWB. Study 3 was a short-term longitudinal study providing further psychometric assessments of PAPS-10. Study 3 found that the PAPS-10 was temporally stable and distinct for a host of related constructs. The third aim of my project was to provide a theoretical framework for understanding the FWB and SWB relationship. To achieve this, I developed the purpose-imbuing model of FWB. The model posits that the primary function of FWB is to imbue people’s lives with meaning, and by so doing establish adaptive well-being. Finally, and most importantly, the fourth aim of my project was to experimentally test the propose-imbuing model of FWB and determine if the FWB and SWB relationships were causal. For Study 4, I used a 3 (anti-FWB vs. pro-FWB vs. control) X Continuous (meaning in life) between-groups experimental design to manipulate FWB and assess its downstream effects on meaning in life and both eudainomic and hedonic well-being. I hypothesized that a pro-FWB manipulation would result in more adaptive 9 eudainomic and hedonic well-being (compared to a control) due to the manipulation bolstering perceived meaning in life (compared to a control). I also hypothesized that an anti-FWB manipulation would result in less adaptive eudainomic and hedonic well-being (compared to a control) due to the manipulation diminishing perceived meaning in life (compared to a control). All primary hypotheses of Study 4 were confirmed. The results and their implications are discussed in detail

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

Population‐based cohort study of outcomes following cholecystectomy for benign gallbladder diseases

Background The aim was to describe the management of benign gallbladder disease and identify characteristics associated with all‐cause 30‐day readmissions and complications in a prospective population‐based cohort. Methods Data were collected on consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing all‐cause 30‐day readmissions and complications were analysed by means of multilevel, multivariable logistic regression modelling using a two‐level hierarchical structure with patients (level 1) nested within hospitals (level 2). Results Data were collected on 8909 patients undergoing cholecystectomy from 167 hospitals. Some 1451 cholecystectomies (16·3 per cent) were performed as an emergency, 4165 (46·8 per cent) as elective operations, and 3293 patients (37·0 per cent) had had at least one previous emergency admission, but had surgery on a delayed basis. The readmission and complication rates at 30 days were 7·1 per cent (633 of 8909) and 10·8 per cent (962 of 8909) respectively. Both readmissions and complications were independently associated with increasing ASA fitness grade, duration of surgery, and increasing numbers of emergency admissions with gallbladder disease before cholecystectomy. No identifiable hospital characteristics were linked to readmissions and complications. Conclusion Readmissions and complications following cholecystectomy are common and associated with patient and disease characteristics

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

Predicting the difficult laparoscopic cholecystectomy: development and validation of a pre-operative risk score using an objective operative difficulty grading system

Background: The prediction of a difficult cholecystectomy has traditionally been based on certain pre-operative clinical and imaging factors. Most of the previous literature reported small patient cohorts and have not used an objective measure of operative difficulty. The aim of this study was to develop a pre-operative score to predict difficult cholecystectomy, as defined by a validated intra-operative difficulty grading scale. Method: Two cohorts from prospectively maintained databases of patients who underwent laparoscopic cholecystectomy were analysed: the CholeS Study (8755 patients) and a single surgeon series (4089 patients). Factors potentially predictive of difficulty were correlated to the Nassar intra-operative difficulty scale. A multivariable binary logistic regression analysis was then used to identify factors that were independently associated with difficult laparoscopic cholecystectomy, defined as operative difficulty grades 3 to 5. The resulting model was then converted to a risk score, and validated on both internal and external datasets. Result: Increasing age and ASA classification, male gender, diagnosis of CBD stone or cholecystitis, thick-walled gallbladders, CBD dilation, use of pre-operative ERCP and non-elective operations were found to be significant independent predictors of difficult cases. A risk score based on these factors returned an area under the ROC curve of 0.789 (95% CI 0.773–0.806, p ' 0.001) on external validation, with 11.0% versus 80.0% of patients classified as low versus high risk having difficult surgeries. Conclusion: We have developed and validated a pre-operative scoring system that uses easily available pre-operative variables to predict difficult laparoscopic cholecystectomies. This scoring system should assist in patient selection for day case surgery, optimising pre-operative surgical planning (e.g. allocation of the procedure to a suitably trained surgeon) and counselling patients during the consent process. The score could also be used to risk adjust outcomes in future research