scholarly journals Choice bundling, unpacked: Observed and predicted effects on intertemporal choice in an additive model of hyperbolic delay discounting

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259830
Author(s):  
Jeffrey S. Stein ◽  
Gregory J. Madden
Keyword(s):  
Delay Discounting ◽  
Clinical Utility ◽  
Intertemporal Choice ◽  
Additive Model ◽  
Hyperbolic Discounting ◽  
Future Research ◽  
Size Difference ◽  
Magnitude Effect ◽  
Total Reward ◽  
Bundle Size

One method known to increase preference for larger, later rewards (LLRs) over smaller, sooner rewards (SSRs) is choice bundling, in which a single choice produces a series of repeating consequences over time. The present study examined whether effects of choice bundling on preference for LLRs: (1) increase with the number of rewards in the bundle (i.e., bundle size); (2) are independent of differences in reward magnitude between conditions; and (3) accord with predictions of an additive model of hyperbolic delay discounting, in which the value of a bundle of rewards can be expressed as the summed discounted value of all rewards in that bundle. Participants (N = 252) completed a choice task to assess valuation of monetary LLRs at bundle sizes of 1 (control), 3, and 9 rewards per choice (ascending/descending order counterbalanced). To control for the magnitude effect, the total reward amounts were held constant across conditions. Choice bundling significantly increased LLR preference (p < .001), with the largest effect observed at the largest bundle size. The descending bundle-size order produced significantly greater LLR preference than the ascending order (p < .05), although order did not significantly interact with bundle size. Difference scores between observed measures and those predicted by an additive model of hyperbolic discounting were small and not significantly different than zero, but were not equivalent to zero. Future research should investigate the clinical utility of choice bundling for reducing the maladaptive health behavior (e.g., substance use) with which delay discounting is associated.

How Might We Screen for Psychological Factors in People With Pelvic Pain? An e-Delphi Study

2021 ◽  
Author(s):  
Angela Pontifex ◽  
Caris Savin ◽  
Caitlin Park ◽  
Alina Filipe Nunes ◽  
K Jane Chalmers ◽  
...  
Keyword(s):  
Focus Group ◽  
Pelvic Pain ◽  
Delphi Method ◽  
Delphi Study ◽  
Psychological Factors ◽  
Clinical Utility ◽  
Delphi Process ◽  
Future Research ◽  
Exclusion Criteria ◽  
Group Design

Abstract Objective Persistent pelvic pain is a complex condition often influenced by psychological factors that can alter treatment outcomes. These factors are potentially modifiable; however, currently there is no instrument to screen for them in these individuals. The purpose of this study was to determine (1) which psychological factors should be screened in individuals with persistent pelvic pain and (2) the most appropriate statements to represent these psychological factors. Methods The study used a focus group design followed by an electronic-Delphi (e-Delphi) process. A focus group consisting of 8 experts was conducted to determine the relevant psychological factors to screen. These results informed round 1 of the e-Delphi process, consisting of a panel of 14 pain/pelvic pain experts. The e-Delphi process consisted of 3 rounds of online surveys and 2 teleconference discussions to establish consensus on the most appropriate statement to screen for each of the psychological factors. Results The focus group identified 13 relevant psychological factors. During the e-Delphi process, relevant screening statements were assessed using a 100-point allocation system. Experts could reword and suggest new statements. Statements were assessed for consensus and stability and were eliminated as the rounds progressed if they met the exclusion criteria. At the termination of round 3, there were 15 statements remaining. Conclusions The final list of 15 statements will assist clinicians in screening for psychological factors and is an important step for clinicians in providing psychologically informed care to people with persistent pelvic pain. Future research should determine the psychometric properties of the statements to determine their clinical utility as a questionnaire. Impact This study has refined a list of statements to help screen for psychological factors in individuals with persistent pelvic pain. Developed robustly using an e-Delphi method, this list is an important first step forward for clinicians to provide psychologically informed care to these individuals.

scholarly journals Does the model of additive effect in placebo research still hold true? A narrative review

JRSM Open ◽  
2017 ◽  
Vol 8 (3) ◽  
pp. 205427041668143 ◽  
Author(s):  
Katja Boehm ◽  
Bettina Berger ◽  
Ulrich Weger ◽  
Peter Heusser
Keyword(s):  
Context Effects ◽  
Experimental Studies ◽  
Additive Model ◽  
Drug Effects ◽  
Future Research ◽  
Inclusion Criteria ◽  
Integrative Study ◽  
Additive Relation ◽  
Specific Factors ◽  
Study Designs

Personalised and contextualised care has been turned into a major demand by people involved in healthcare suggesting to move toward person-centred medicine. The assessment of person-centred medicine can be most effectively achieved if treatments are investigated using ‘with versus without’ person-centredness or integrative study designs. However, this assumes that the components of an integrative or person-centred intervention have an additive relationship to produce the total effect. Beecher’s model of additivity assumes an additive relation between placebo and drug effects and is thus presenting an arithmetic summation. So far, no review has been carried out assessing the validity of the additive model, which is to be questioned and more closely investigated in this review. Initial searches for primary studies were undertaken in July 2016 using Pubmed and Google Scholar. In order to find matching publications of similar magnitude for the comparison part of this review, corresponding matches for all included reviews were sought. A total of 22 reviews and 3 clinical and experimental studies fulfilled the inclusion criteria. The results pointed to the following factors actively questioning the additive model: interactions of various effects, trial design, conditioning, context effects and factors, neurobiological factors, mechanism of action, statistical factors, intervention-specific factors (alcohol, caffeine), side-effects and type of intervention. All but one of the closely assessed publications was questioning the additive model. A closer examination of study design is necessary. An attempt in a more systematic approach geared towards solutions could be a suggestion for future research in this field.

scholarly journals Systematic Review and Meta-Analysis of Virtual Reality in Mental Healthcare: Effects of Full Body Illusions on Body Image Disturbance

2021 ◽  
Vol 2 ◽  
Author(s):  
Collin Turbyne ◽  
Abe Goedhart ◽  
Pelle de Koning ◽  
Frederike Schirmbeck ◽  
Damiaan Denys
Keyword(s):  
Body Image ◽  
Virtual Reality ◽  
Body Size ◽  
Clinical Utility ◽  
Meta Analysis ◽  
Future Research ◽  
Head Mounted Display ◽  
Full Body ◽  
Virtual Body ◽  
Clinical Populations

Background: Body image (BI) disturbances have been identified in both clinical and non-clinical populations. Virtual reality (VR) has recently been used as a tool for modulating BI disturbances through the use of eliciting a full body illusion (FBI). This meta-analysis is the first to collate evidence on the effectiveness of an FBI to reduce BI disturbances in both clinical and non-clinical populations.Methods: We performed a literature search in MEDLINE (PubMed), EMBASE, PsychINFO, and Web of Science with the keywords and synonyms for “virtual reality” and “body image” to identify published studies until September 2020. We included studies that (1) created an FBI with a modified body shape or size and (2) reported BI disturbance outcomes both before and directly after the FBI. FBI was defined as a head-mounted display (HMD)-based simulation of embodying a virtual body from an egocentric perspective in an immersive 3D computer-generated environment.Results: Of the 398 identified unique studies, 13 were included after reading full-texts. Four of these studies were eligible for a meta-analysis on BI distortion inducing a small virtual body FBI in healthy females. Significant post-intervention results were found for estimations of shoulder width, hip width, and abdomen width, with the largest reductions in size being the estimation of shoulder circumference (SMD = −1.3; 95% CI: −2.2 to −0.4; p = 0.004) and hip circumference (SMD = −1.0; 95% CI: −1.6 to −0.4; p = 0.004). Mixed results were found in non-aggregated studies from large virtual body FBIs in terms of both estimated body size and BI dissatisfaction and in small virtual body FBI in terms of BI dissatisfaction.Conclusions: The findings presented in this paper suggest that the participants' BIs were able to conform to both an increased as well as a reduced virtual body size. However, because of the paucity of research in this field, the extent of the clinical utility of FBIs still remains unclear. In light of these limitations, we provide implications for future research about the clinical utility of FBIs for modulating BI-related outcomes.

scholarly journals Power analyses for moderator effects with (non)randomly varying slopes in cluster randomized trials

Methodology ◽  
2021 ◽  
Vol 17 (2) ◽  
pp. 92-110
Author(s):  
Nianbo Dong ◽  
Jessaca Spybrook ◽  
Benjamin Kelcey ◽  
Metin Bulus
Keyword(s):  
Statistical Power ◽  
Randomized Trials ◽  
Future Research ◽  
Size Difference ◽  
Detectable Effect ◽  
Cluster Randomized Trials ◽  
Individual Level ◽  
Moderator Effects ◽  
Cluster Randomized ◽  
Power Analyses

Researchers often apply moderation analyses to examine whether the effects of an intervention differ conditional on individual or cluster moderator variables such as gender, pretest, or school size. This study develops formulas for power analyses to detect moderator effects in two-level cluster randomized trials (CRTs) using hierarchical linear models. We derive the formulas for estimating statistical power, minimum detectable effect size difference and 95% confidence intervals for cluster- and individual-level moderators. Our framework accommodates binary or continuous moderators, designs with or without covariates, and effects of individual-level moderators that vary randomly or nonrandomly across clusters. A small Monte Carlo simulation confirms the accuracy of our formulas. We also compare power between main effect analysis and moderation analysis, discuss the effects of mis-specification of the moderator slope (randomly vs. non-randomly varying), and conclude with directions for future research. We provide software for conducting a power analysis of moderator effects in CRTs.

scholarly journals Machine Learning Models of COVID-19 Cases in the United States: A Study of Initial Lockdown and Reopen Regimes

2021 ◽  
Vol 11 (23) ◽  
pp. 11227
Author(s):  
Arnold Kamis ◽  
Yudan Ding ◽  
Zhenzhen Qu ◽  
Chenchen Zhang
Keyword(s):  
United States ◽  
Machine Learning ◽  
Additive Model ◽  
Regression Tree ◽  
Predictor Variable ◽  
The United States ◽  
Predictor Variables ◽  
Future Research ◽  
Machine Learning Methods ◽  
Variance Explained

The purpose of this paper is to model the cases of COVID-19 in the United States from 13 March 2020 to 31 May 2020. Our novel contribution is that we have obtained highly accurate models focused on two different regimes, lockdown and reopen, modeling each regime separately. The predictor variables include aggregated individual movement as well as state population density, health rank, climate temperature, and political color. We apply a variety of machine learning methods to each regime: Multiple Regression, Ridge Regression, Elastic Net Regression, Generalized Additive Model, Gradient Boosted Machine, Regression Tree, Neural Network, and Random Forest. We discover that Gradient Boosted Machines are the most accurate in both regimes. The best models achieve a variance explained of 95.2% in the lockdown regime and 99.2% in the reopen regime. We describe the influence of the predictor variables as they change from regime to regime. Notably, we identify individual person movement, as tracked by GPS data, to be an important predictor variable. We conclude that government lockdowns are an extremely important de-densification strategy. Implications and questions for future research are discussed.

scholarly journals Temporal discounting in adolescents and adults with Tourette syndrome

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253620
Author(s):  
Canan Beate Schüller ◽  
Ben Jonathan Wagner ◽  
Thomas Schüller ◽  
Juan Carlos Baldermann ◽  
Daniel Huys ◽  
...  
Keyword(s):  
Tourette Syndrome ◽  
Positive Reinforcement ◽  
Intertemporal Choice ◽  
Neurodevelopmental Disorder ◽  
Temporal Discounting ◽  
Hyperbolic Discounting ◽  
Developmental Trajectory ◽  
Adult Patients ◽  
Control Functions ◽  
Male Subjects

Tourette syndrome is a neurodevelopmental disorder associated with hyperactivity in dopaminergic networks. Dopaminergic hyperactivity in the basal ganglia has previously been linked to increased sensitivity to positive reinforcement and increases in choice impulsivity. In this study, we examine whether this extends to changes in temporal discounting, where impulsivity is operationalized as an increased preference for smaller-but-sooner over larger-but-later rewards. We assessed intertemporal choice in two studies including nineteen adolescents (age: mean[sd] = 14.21[±2.37], 13 male subjects) and twenty-five adult patients (age: mean[sd] = 29.88 [±9.03]; 19 male subjects) with Tourette syndrome and healthy age- and education matched controls. Computational modeling using exponential and hyperbolic discounting models via hierarchical Bayesian parameter estimation revealed reduced temporal discounting in adolescent patients, and no evidence for differences in adult patients. Results are discussed with respect to neural models of temporal discounting, dopaminergic alterations in Tourette syndrome and the developmental trajectory of temporal discounting. Specifically, adolescents might show attenuated discounting due to improved inhibitory functions that also affect choice impulsivity and/or the developmental trajectory of executive control functions. Future studies would benefit from a longitudinal approach to further elucidate the developmental trajectory of these effects.

scholarly journals Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018

2020 ◽  
Vol 54 (11) ◽  
pp. 631-641 ◽  
Author(s):  
Michael P Reiman ◽  
Rintje Agricola ◽  
Joanne L Kemp ◽  
Joshua J Heerey ◽  
Adam Weir ◽  
...  
Keyword(s):  
Diagnostic Imaging ◽  
Clinical Utility ◽  
Acetabular Dysplasia ◽  
Ligamentum Teres ◽  
Research Network ◽  
Future Research ◽  
Middle Aged ◽  
Hip Instability ◽  
Active Adults ◽  
Fai Syndrome

There is no agreement on how to classify, define or diagnose hip-related pain—a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion–adduction–internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head–neck radiographs are the initial diagnostic imaging of choice—advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

scholarly journals Clinical Perspective on Internet of Things Applications for Care of the Elderly

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1925
Author(s):  
Soe Ye Yint Tun ◽  
Samaneh Madanian ◽  
Dave Parry
Keyword(s):  
Internet Of Things ◽  
Older People ◽  
Clinical Utility ◽  
Elderly Care ◽  
The Elderly ◽  
Aged Care ◽  
Information Technology Professionals ◽  
Future Research ◽  
Iot Applications ◽  
Iot Devices

The elderly population is increasing globally, putting more pressure on aged care and public health systems. To address this issue and help increase the independence of older people, different digital technologies, including the Internet of things (IoT), can play an important role. Although there has been an increase in the number of studies in this field, most of them concentrate on IoT applications in elderly care from a technology perspective, with very little contribution from the clinical side. Therefore, this paper aims to investigate and identify the available IoT applications and their clinical utility for common diseases in elderly people. The results of this study could be useful for information technology professionals in developing and understanding the clinical requirements for IoT applications in healthcare for older people. Clinicians will also be informed about the clinical possibilities of using IoT devices in this area. Based on our findings, future research should focus on enhancing the clinical utility of current IoT applications in different settings and on developing new applications to support practitioners and older people.

Discount models in intertemporal choice: an empirical analysis

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Isabel María Parra Oller ◽  
Salvador Cruz Rambaud ◽  
María del Carmen Valls Martínez
Keyword(s):  
Empirical Analysis ◽  
Intertemporal Choice ◽  
Hyperbolic Discounting ◽  
Least Squares Regression ◽  
Discount Function ◽  
Content Type ◽  
The Individual ◽  
Gains And Losses ◽  
First Time ◽  
The Empirical Analysis

PurposeThe main purpose of this paper is to determine the discount function which better fits the individuals' preferences through the empirical analysis of the different functions used in the field of intertemporal choice.Design/methodology/approachAfter an in-depth revision of the existing literature and unlike most studies which only focus on exponential and hyperbolic discounting, this manuscript compares the adjustment of data to six different discount functions. To do this, the analysis is based on the usual statistical methods, and the non-linear least squares regression, through the algorithm of Gauss-Newton, in order to estimate the models' parameters; finally, the AICc method is used to compare the significance of the six proposed models.FindingsThis paper shows that the so-called q-exponential function deformed by the amount is the model which better explains the individuals' preferences on both delayed gains and losses. To the extent of the authors' knowledge, this is the first time that a function different from the general hyperbola fits better to the individuals' preferences.Originality/valueThis paper contributes to the search of an alternative model able to explain the individual behavior in a more realistic way.

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