96 results found
Vlaev I, Crockett MJ, Clark L, et al., 2017, Serotonin enhances the impact of health information on food choice, COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE, Vol: 17, Pages: 542-553, ISSN: 1530-7026
Thomson CL, Maskrey N, Vlaev I, 2017, Making Decisions Better: an evaluation of an educational intervention, JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Vol: 23, Pages: 251-256, ISSN: 1356-1294
Taylor MJ, Taylor D, Vlaev I, et al., 2017, Virtual worlds to support patient group communication? A questionnaire study investigating potential for virtual world focus group use by respiratory patients, BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Vol: 48, Pages: 451-461, ISSN: 0007-1013
Taylor MJ, Vlaev I, Taylor D, et al., 2017, Cardiac autonomic regulation as a predictor for childhood obesity intervention success, INTERNATIONAL JOURNAL OF OBESITY, Vol: 41, Pages: 824-827, ISSN: 0307-0565
Childhood obesity is a major public health concern; behavioural interventions induce weight reduction in some, but success is variable. Heart rate variability (HRV) has been associated with impulse control and extent of dieting success. This study investigated the relationship between HRV and post childhood obesity intervention weight-management success, and involved recording the frequency-domain HRV measures ratio between low frequency and high frequency power (LF/HF) and high frequency power (HF), and the time-domain measure, percentage of successive beat-to-beat intervals that differ by more than 50ms (PNN50). It was expected that greater LF/HF and lower HF would be associated with greater post-intervention weight gain, and that greater PNN50 would be associated with greater impulse control. Seventy-four participants aged 9–14 (M=10.7; s.d.: 1.1) attended a weight-management camp, where HRV was recorded. Stop signal reaction time (SSRT) was also recorded as a measure of impulse control. As expected, SSRT was positively associated with pre-intervention body mass (r=0.301, P=0.010) and negatively associated with PNN50 (β=0.29, P=0.031). Post-intervention body mass change was positively associated with LF/HF (β=0.34, P=0.037), but was not associated with HF. Lifestyle interventions may have a greater chance of effectively supporting long-term weight-management for children with lower LF/HF; assessing HRV of obese children may be helpful in informing obesity treatment decisions.
Leff DR, Yongue G, Vlaev I, et al., 2017, "Contemplating the next maneuver": functional neuroimaging reveals intraoperative decision-making strategies, Annals of Surgery, Vol: 265, Pages: 320-330, ISSN: 1528-1140
OBJECTIVE: To investigate differences in the quality, confidence, and consistency of intraoperative surgical decision making (DM) and using functional neuroimaging expose decision systems that operators use. SUMMARY BACKGROUND DATA: Novices are hypothesized to use conscious analysis (effortful DM) leading to activation across the dorsolateral prefrontal cortex, whereas experts are expected to use unconscious automation (habitual DM) in which decisions are recognition-primed and prefrontal cortex independent. METHODS: A total of 22 subjects (10 medical student novices, 7 residents, and 5 attendings) reviewed simulated laparoscopic cholecystectomy videos, determined the next safest operative maneuver upon video termination (10 s), and reported decision confidence. Video paradigms either declared ("primed") or withheld ("unprimed") the next operative maneuver. Simultaneously, changes in cortical oxygenated hemoglobin and deoxygenated hemoglobin inferring prefrontal activation were recorded using Optical Topography. Decision confidence, consistency (primed vs unprimed), and quality (script concordance) were assessed. RESULTS: Attendings and residents were significantly more certain (P < 0.001), and decision quality was superior (script concordance: attendings = 90%, residents = 78.3%, and novices = 53.3%). Decision consistency was significantly superior in experts (P < 0.001) and residents (P < 0.05) than novices (P = 0.183). During unprimed DM, novices showed significant activation of the dorsolateral prefrontal cortex, whereas this activation pattern was not observed among residents and attendings. During primed DM, significant activation was not observed in any group. CONCLUSIONS: Expert DM is characterized by improved quality, consistency, and confidence. The findings imply attendings use a habitual decision system, whereas novices use an effortful approach under uncertainty. In the presence of operative cues (primes), novices disengage
Kulendran M, Borovoi L, Purkayastha S, et al., 2017, Impulsivity predicts weight loss after obesity surgery, Surgery for Obesity and Related Diseases, Vol: 13, Pages: 1033-1040, ISSN: 1550-7289
ObjectiveThere is evidence that executive function, and specifically inhibitory control, is related to obesity and eating behavior. The goal of this study was to determine whether personality traits and inhibitory control predict weight loss after bariatric procedures. Although the impressive weight reduction after bariatric surgery has been shown in short- and medium-term studies, the effect of personality traits on this reduction is uncertain. Specifically, the effect of impulsivity is still largely unknown.SettingPatients attending either a multidisciplinary information session or outpatient clinic at the Imperial Weight Management Centre were recruited with informed consent into the trial over a 4-month period from January to April 2013. Participants were invited to attend behavioral testing on an outpatient basis in a silent room invigilated by a single researcher.MethodsForty-five bariatric patients participated in the study (25 patients had a gastric bypass, with a mean BMI of 41.8 and age of 39.0 years; 20 had a sleeve gastrectomy, with a mean BMI of 47.2 and age of 49.0 years). All patients completed personality measures of impulsivity—Barratt’s Impulsivity Scale, as well as behavioral measures of impulsivity—the stop-signal reaction-time (SSRT) task measuring inhibitory control and the temporal discounting task measuring reward processing. Those measures were examined in relation to weight loss 6 months after surgery.ResultsThe surgical procedure and changes in the behavioral measure of inhibitory control (SSRT) were found to be significant predictors of reduction in body mass index (BMI) in patients undergoing bariatric surgery. The sleeve gastrectomy group found a reduction in BMI of 14.1%, which was significantly less than the 25% reduction in BMI in the gastric bypass group. The direction (parameter estimate) of the significant effect was positive for SSRT change, which indicates that pre- and postreduction in impulsivity predicts red
Schmidtke KA, Watson DG, Vlaev I, 2017, The use of control charts by laypeople and hospital decision-makers for guiding decision making, QUARTERLY JOURNAL OF EXPERIMENTAL PSYCHOLOGY, Vol: 70, Pages: 1114-1128, ISSN: 1747-0218
Kulendran M, Vlaev I, King D, et al., 2016, The use of commitment techniques to support weight loss maintenance in obese adolescents., Psychology & Health, Vol: 31, Pages: 1332-1341, ISSN: 1476-8321
OBJECTIVES: Obesity is a rising problem in adolescents related to unhealthy behaviours. Commitment devises are one type of behavioural intervention that may help people change their behaviours. The current pilot trial tests whether commitment devices delivered via text message help adolescents maintain their recent weight loss. METHODS: During a 12-week pilot trial adolescents who attended a weight loss camp were randomly assigned to either received text messages that contained only information, i.e., advice, about weight loss management (n=13) or asked for them to commit to following the same advise (n=14). RESULTS: The BMI of the adolescents in the commitment group did not change. In contrast, the BMI of adolescents in the information group increased. A linear regression revealed that group was a significant predictor of BMI change. A logistic regression revealed that adolescents in the information group were nearly eight times more likely to regain weight than those in the commitment group. CONCLUSIONS: This is the first study with adolescents to show weight maintenance using a commitment device. The results suggest that commitment devices can help adolescents maintain their recent weight loss.
Vlaev I, King D, Dolan P, et al., 2016, The Theory and Practice of "Nudging": Changing Health Behaviors, Public Administration Review, Vol: 76, Pages: 550-561, ISSN: 1540-6210
Taylor D, Murphy J, Ahmad M, et al., 2016, Quantified-self for obesity: physical activity behaviour sensing to improve health outcomes, Publisher: IOS Press, Pages: 414-416, ISSN: 1879-8365
Physical activity levels in bariatric patients have not been well documented, despite their importance in maintaining weight loss following surgery. This study investigated the feasibility of tracking physical activity using a smartphone app with minimal user interaction. Thus far, we have obtained good quality data from 255 patients at various points in their weight loss journey. Preliminary analyses indicate little change in physical activity levels following surgery with pre-surgery patients reaching an average of 16 minutes per day and post-surgery patients achieving a daily average of 21 minutes. Further analyses using machine-learning techniques will be conducted to determine whether physical activity is a critical factor in distinguishing between successful and unsuccessful weight loss outcomes and in the resolution of comorbid conditions in patients with similar clinical profiles.
Schmidtke KA, Poots A, Carpo J, et al., 2016, Considering chance in quality and safety performance measures: an analysis of performance reports by boards in English NHS trusts, BMJ Quality & Safety, Vol: 26, Pages: 61-69, ISSN: 2044-5423
Objectives Hospital board members are asked to consider large amounts of quality and safety data with a duty to act on signals of poor performance. However, in order to do so it is necessary to distinguish signals from noise (chance). This article investigates whether data in English National Health Service (NHS) acute care hospital board papers are presented in a way that helps board members consider the role of chance in their decisions.Methods Thirty English NHS trusts were selected at random and their board papers retrieved. Charts depicting quality and safety were identified. Categorical discriminations were then performed to document the methods used to present quality and safety data in board papers, with particular attention given to whether and how the charts depicted the role of chance, that is, by including control lines or error bars.Results Thirty board papers, containing a total of 1488 charts, were sampled. Only 88 (6%) of these charts depicted the role of chance, and only 17 of the 30 board papers included any charts depicting the role of chance. Of the 88 charts that attempted to represent the role of chance, 16 included error bars and 72 included control lines. Only 6 (8%) of the 72 control charts indicated where the control lines had been set (eg, 2 vs 3 SDs).Conclusions Hospital board members are expected to consider large amounts of information. Control charts can help board members distinguish signals from noise, but often boards are not using them. We discuss demand-side and supply-side barriers that could be overcome to increase use of control charts in healthcare.
Judah G, Vlaev I, Gunn L, et al., 2016, Incentives in Diabetic Eye Assessment by Screening (IDEAS): study protocol of a three-arm randomized controlled trial using financial incentives to increase screening uptake in London., BMC Ophthalmology, Vol: 16, ISSN: 1471-2415
BACKGROUND: Diabetes is an increasing public health problem in the UK and globally. Diabetic retinopathy is a microvascular complication of diabetes, and is one of the leading causes of blindness in the UK working age population. The diabetic eye screening programme in England aims to invite all people with diabetes aged 12 or over for retinal photography to screen for the presence of diabetic retinopathy. However, attendance rates are only 81 %, leaving many people at risk of preventable sight loss. METHODS: This is a three arm randomized controlled trial to investigate the impact of different types of financial incentives (based on principles from behavioral economics) on increasing attendance at diabetic eye screening appointments in London. Eligible participants will be aged 16 or over, and are those who have been invited to screening appointments annually, but who have not attended, or telephoned to rearrange an appointment, within the last 24 months. Eligible participants will be randomized to one of three conditions: 1. Control condition (usual invitation letter) 2. Fixed incentive condition (usual invitation letter, including a voucher for £10 if they attend their appointment) 3. Probabilistic incentive condition (invitation letter, including a voucher for a 1 in 100 chance of winning £1000 if they attend their appointment). Participants will be sent invitation letters, and the primary outcome will be whether or not they attend their appointment. One thousand participants will be included in total, randomized with a ratio of 1.4:1:1. In order to test whether the incentive scheme has a differential impact on patients from different demographic or socio-economic groups, information will be recorded on age, gender, distance from screening center, socio-economic status and length of time since they were last screened. A cost-effectiveness analysis will also be performed. DISCUSSION: This study will be the first trial of financial incentives
Kulendran M, Patel K, Darzi A, et al., 2016, Diagnostic validity of behavioural and psychometric impulsivity measures: An assessment of impulsivity measures in five subject groups, 7th BOMSS Annual Scientific Meeting, Publisher: WILEY-BLACKWELL, Pages: 1-2, ISSN: 0007-1323
Kulendran M, Wingfield LR, Sugden C, et al., 2016, Pharmacological manipulation of impulsivity: A randomized controlled trial, PERSONALITY AND INDIVIDUAL DIFFERENCES, Vol: 90, Pages: 321-325, ISSN: 0191-8869
Kulendran M, Patel K, Darzi A, et al., 2016, Diagnostic validity of behavioural and psychometric impulsivity measures: An assessment in adolescent and adult populations, PERSONALITY AND INDIVIDUAL DIFFERENCES, Vol: 90, Pages: 347-352, ISSN: 0191-8869
Taylor MJ, Taylor D, Gamboa P, et al., 2016, Using Motion-Sensor Games to Encourage Physical Activity for Adults with Intellectual Disability., Medicine Meets Virtual Reality 22, Publisher: IOS Press Ebooks, Pages: 417-423, ISBN: 978-1-61499-625-5
Adults with Intellectual Disability (ID) are at high risk of being in poor health as a result of exercising infrequently; recent evidence indicates this is often due to there being a lack of opportunities to exercise. This pilot study involved an investigation of the use of motion-sensor game technology to enable and encourage exercise for this population. Five adults (two female; 3 male, aged 34-74 [M = 55.20, SD = 16.71] with ID used motion-sensor games to conduct exercise at weekly sessions at a day-centre. Session attendees reported to have enjoyed using the games, and that they would like to use the games in future. Interviews were conducted with six (four female; two male, aged 27-51 [M = 40.20, SD = 11.28]) day-centre staff, which indicated ways in which the motion-sensor games could be improved for use by adults with ID, and barriers to consider in relation to their possible future implementation. Findings indicate motion-sensor games provide a useful, enjoyable and accessible way for adults with ID to exercise. Future research could investigate implementation of motion-sensor games as a method for exercise promotion for this population on a larger scale.
King D, Vlaev I, Everett-Thomas R, et al., 2016, "Priming" hand hygiene compliance in clinical environments, Health Psychology, Vol: 35, Pages: 96-101, ISSN: 1930-7810
Effective hand hygiene is the single most important procedure in preventing hospital-acquired infections. Traditional information/education-based interventions have shown only modest benefits on compliance. This study set out to investigate whether priming via olfactory and visual cues influences hand hygiene compliance. Method: Randomized controlled trial set in a surgical intensive care unit (SICU) at a teaching hospital in Miami, Florida. The primary outcome data involved observations—a mix of health professionals and service users were observed entering the SICU by 2 trained observers and their hand hygiene compliance was independently verified. Interventions included either an olfactory prime (clean, citrus smell) or visual prime (male or female eyes). The primary outcome measure was hand hygiene compliance (HHC) measured by the visitor using the hand gel dispenser. Results: At a 5% level there was significant evidence that a clean, citrus smell significantly improves HHC (46.9% vs. 15.0%, p = .0001). Compared to the control group, a significant improvement in HHC was seen when a picture of “male eyes” was placed over the hand gel dispenser (33.3% vs. 15.0%, p < .038). No significant improvement in HHC was seen when a picture of female eyes was placed over the same hand gel dispenser (10.0% vs. 15.0%, p = .626). Conclusions: This is one of the first studies to demonstrate that priming can influence HHC in a clinical setting. The findings suggest that priming interventions could be used to change other behaviors relevant to public health
Taylor MJ, Arriscado D, Vlaev I, et al., 2016, Measuring perceived exercise capability and investigating its relationship with childhood obesity: a feasibility study, International Journal of Obesity, Vol: 40, Pages: 34-38, ISSN: 1476-5497
Background/Objectives: According to the COM-B ('Capability', 'Opportunity', 'Motivation' and 'Behaviour') model of behaviour, three factors are essential for behaviour to occur: capability, opportunity and motivation. Obese children are less likely to feel capable of exercising. The implementation of a new methodological approach to investigate the relationship between perceived exercise capability (PEC) and childhood obesity was conducted, which involved creating a new instrument, and demonstrating how it can be used to measure obesity intervention outcomes.Subjects/Methods: A questionnaire aiming to measure perceived exercise capability, opportunity and motivation was systematically constructed using the COM-B model and administered to 71 obese children (aged 9–17 years (12.24±0.2.01), body mass index (BMI) standard deviation scores (SDS) 2.80±0.660) at a weight-management camp in northern England. Scale validity and reliability was assessed. Relationships between PEC, as measured by the questionnaire, and BMI SDS were investigated for the children at the weight-management camp, and for 45 Spanish schoolchildren (aged 9–13 years, (10.52±1.23), BMI SDS 0.80±0.99). A pilot study, demonstrating how the questionnaire can be used to measure the effectiveness of an intervention aiming to bring about improved PEC for weight-management camp attendees, was conducted. No participants withdrew from these studies.Results: The questionnaire domain (exercise capability, opportunity and motivation) composite scales were found to have adequate internal consistency (a=0.712–0.796) and construct validity (χ2/degrees of freedom=1.55, root mean square error of approximation=0.072, comparative fit index=0.92). Linear regression revealed that low PEC was associated with higher baseline BMI SDS for both UK (b=−0.289, P=0.010) and Spanish (b=−0.446, P=0.047) participants. Pilot study findings provide preliminary evidence for P
Taylor MJ, Vlaev I, Maltby J, et al., 2015, Improving Social Norms Interventions: Rank-Framing Increases Excessive Alcohol Drinkers' Information-Seeking, HEALTH PSYCHOLOGY, Vol: 34, Pages: 1200-1203, ISSN: 0278-6133
Wadge H, Bicknell C, Vlaev I, 2015, Perceived ethical acceptability of financial incentives to improve diabetic eye screening attendance, BMJ Open Diabetes Research and Care, Vol: 3, ISSN: 2052-4897
OBJECTIVE: To test the ethical acceptability of using financial incentives to increase diabetic retinopathy screening attendance. BACKGROUND: Financial incentives could be an effective way to increase attendance at screening for diabetic retinopathy, although there can be ethical concerns about this approach. DESIGN: Survey of people with diabetes in North West London. Those who were due to attend a screening appointment were invited to complete a questionnaire. Key demographic variables included age, gender, and deprivation. SETTING AND PARTICIPANTS: A questionnaire was issued to those invited to attend screening in North West London and those who run the screening service. The questionnaire captured views on aspects of the ethical problem and different incentive types. MAIN VARIABLES STUDIED: It captured views on the different dimensions of the ethical problem and different types of incentive. In order to understand how views might vary within a population, demographic variables were used to analyze the results. RESULTS AND CONCLUSIONS: Vouchers were found to be the most acceptable form of incentive, significantly more so than cash payments. Most rejected the notion of targeting those who need incentivizing, preferring equality. Age was an important factor, with those aged between 40 and 64 the most optimistic about the potential benefits. Higher levels of deprivation were linked to increased acceptability scores. While some ethical concerns are strongly held among certain groups, there is also much support for the principle of incentivizing positive behaviors. This paves the way for future research into the effectiveness of incentivizing diabetic retinopathy screening attendance.
People show empathic responses to others’ pain, yet how they choose to apportion pain between themselves and others is not well understood. To address this question, we observed choices to reapportion social allocations of painful stimuli and, for comparison, also elicited equivalent choices with money. On average people sought to equalize allocations of both pain and money, in a manner which indicated that inequality carried an increasing marginal cost. Preferences for pain were more altruistic than for money, with several participants assigning more than half the pain to themselves. Our data indicate that, given concern for others, the fundamental principle of diminishing marginal utility motivates spreading costs across individuals. A model incorporating this assumption outperformed existing models of social utility in explaining the data. By implementing selected allocations for real, we also found that while inequality per se did not influence pain perception, altruistic behavior had an intrinsic analgesic effect for the recipient.
Hallsworth M, Berry D, Sanders M, et al., 2015, Correction: Stating appointment costs in SMS reminders reduces missed hospital appointments: findings from two randomised controlled trials (vol 10, e0137306, 2015), PLoS ONE, Vol: 10, ISSN: 1932-6203
Hallsworth M, Berry D, Sanders M, et al., 2015, Stating Appointment Costs in SMS Reminders Reduces Missed Hospital Appointments: Findings from Two Randomised Controlled Trials, PLOS One, Vol: 10, ISSN: 1932-6203
Story GW, Vlaev I, Dayan P, et al., 2015, Anticipation and choice heuristics in the dynamic consumption of pain relief, Plos Computational Biology, Vol: 11, ISSN: 1553-7358
Humans frequently need to allocate resources across multiple time-steps. Economic theoryproposes that subjects do so according to a stable set of intertemporal preferences, but thecomputational demands of such decisions encourage the use of formally less competentheuristics. Few empirical studies have examined dynamic resource allocation decisionssystematically. Here we conducted an experiment involving the dynamic consumption overapproximately 15 minutes of a limited budget of relief from moderately painful stimuli. Wehad previously elicited the participants’ time preferences for the same painful stimuli in oneoffchoices, allowing us to assess self-consistency. Participants exhibited three characteristicbehaviors: saving relief until the end, spreading relief across time, and early spending, ofwhich the last was markedly less prominent. The likelihood that behavior was heuristic ratherthan normative is suggested by the weak correspondence between one-off and dynamicchoices. We show that the consumption choices are consistent with a combination of simpleheuristics involving early-spending, spreading or saving of relief until the end, with subjectspredominantly exhibiting the last two.
Subashini M, Caris J, Parand A, et al., 2015, Impact of PROMs on Clinician Behaviour Study, International Surgical Congress of the Association-of-Surgeons-of-Great-Britain-and-Ireland (ASGBI), Publisher: WILEY-BLACKWELL, Pages: 148-148, ISSN: 0007-1323
Dolan P, Kavetsos G, Vlaev I, 2014, The Happiness Workout, SOCIAL INDICATORS RESEARCH, Vol: 119, Pages: 1363-1377, ISSN: 0303-8300
Winston JS, Vlaev I, Seymour B, et al., 2014, Relative Valuation of Pain in Human Orbitofrontal Cortex, JOURNAL OF NEUROSCIENCE, Vol: 34, Pages: 14526-14535, ISSN: 0270-6474
Kulendran M, Lim M, Zafar N, et al., 2014, MOTOR IMPULSIVITY AS A PREDICTOR OF WEIGHT LOSS IN BARIATRIC PATIENTS, 6th Congress of the International-Federation-for-the-Surgery-of-Obesity-and-Metabolic-Disorders, European-Chapter (IFSO-EC), Publisher: SPRINGER, Pages: 981-981, ISSN: 0960-8923
Kulendran M, Vlaev I, Wingfield LR, et al., 2014, CAN GAMBLING HABITS AND IMPULSE CONTROL BE USED TO PREDICTOR OF WEIGHT LOSS IN BARIATRIC PATIENTS?, 6th Congress of the International-Federation-for-the-Surgery-of-Obesity-and-Metabolic-Disorders, European-Chapter (IFSO-EC), Publisher: SPRINGER, Pages: 1029-1030, ISSN: 0960-8923
Story G, Vlaev I, Seymour B, et al., 2014, Does temporal discounting explain unhealthy behavior? A systematic review and reinforcement learning perspective, Frontiers in Behavioral Neuroscience, Vol: 8, ISSN: 1662-5153
The tendency to make unhealthy choices is hypothesized to be related to an individual’stemporal discount rate, the theoretical rate at which they devalue delayed rewards.Furthermore, a particular form of temporal discounting, hyperbolic discounting, hasbeen proposed to explain why unhealthy behavior can occur despite healthy intentions.We examine these two hypotheses in turn. We first systematically review studieswhich investigate whether discount rates can predict unhealthy behavior. These studiesreveal that high discount rates for money (and in some instances food or drugrewards) are associated with several unhealthy behaviors and markers of healthstatus, establishing discounting as a promising predictive measure. We secondlyexamine whether intention-incongruent unhealthy actions are consistent with hyperbolicdiscounting. We conclude that intention-incongruent actions are often triggered byenvironmental cues or changes in motivational state, whose effects are not parameterizedby hyperbolic discounting. We propose a framework for understanding these state-basedeffects in terms of the interplay of two distinct reinforcement learning mechanisms: a“model-based” (or goal-directed) system and a “model-free” (or habitual) system. Underthis framework, while discounting of delayed health may contribute to the initiation ofunhealthy behavior, with repetition, many unhealthy behaviors become habitual; if healthgoals then change, habitual behavior can still arise in response to environmental cues. Wepropose that the burgeoning development of computational models of these processeswill permit further identification of health decision-making phenotypes.
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