scholarly journals Flexible random intercept models for binary outcomes using mixtures of normals

2007 ◽  
Vol 51 (11) ◽  
pp. 5220-5235 ◽  
Author(s):  
Brian Caffo ◽  
Ming-Wen An ◽  
Charles Rohde
Keyword(s):  
Binary Outcomes ◽  
Random Intercept

scholarly journals A Unifying Framework for Marginalised Random-Intercept Models of Correlated Binary Outcomes

2013 ◽  
Vol 82 (2) ◽  
pp. 275-295 ◽  
Author(s):  
Bruce J. Swihart ◽  
Brian S. Caffo ◽  
Ciprian M. Crainiceanu
Keyword(s):  
Binary Outcomes ◽  
Random Intercept ◽  
Correlated Binary Outcomes

From Bi-Dimensionality to Uni-Dimensionality in Self-Report Questionnaires

2020 ◽  
pp. 1-14 ◽  
Author(s):  
Bjarne Schmalbach ◽  
Markus Zenger ◽  
Michalis P. Michaelides ◽  
Karin Schermelleh-Engel ◽  
Andreas Hinz ◽  
...  
Keyword(s):  
Factor Model ◽  
Common Factor ◽  
Self Regulation ◽  
Model Fit ◽  
Self Report ◽  
External Criterion ◽  
Common Factor Model ◽  
Random Intercept ◽  
Using Data ◽  
Core Self

Abstract. The common factor model – by far the most widely used model for factor analysis – assumes equal item intercepts across respondents. Due to idiosyncratic ways of understanding and answering items of a questionnaire, this assumption is often violated, leading to an underestimation of model fit. Maydeu-Olivares and Coffman (2006) suggested the introduction of a random intercept into the model to address this concern. The present study applies this method to six established instruments (measuring depression, procrastination, optimism, self-esteem, core self-evaluations, and self-regulation) with ambiguous factor structures, using data from representative general population samples. In testing and comparing three alternative factor models (one-factor model, two-factor model, and one-factor model with a random intercept) and analyzing differential correlational patterns with an external criterion, we empirically demonstrate the random intercept model’s merit, and clarify the factor structure for the above-mentioned questionnaires. In sum, we recommend the random intercept model for cases in which acquiescence is suspected to affect response behavior.

Translocation Relative to Range

Methodology ◽  
2008 ◽  
Vol 4 (3) ◽  
pp. 132-138 ◽  
Author(s):  
Michael Höfler
Keyword(s):  
Risk Difference ◽  
Binary Outcomes ◽  
Number Needed To Treat ◽  
Likert Scales ◽  
Psychological Science ◽  
The Absolute ◽  
The Difference ◽  
Variance Parameters ◽  
Standardized Index ◽  
Maximum Possible Magnitude

A standardized index for effect intensity, the translocation relative to range (TRR), is discussed. TRR is defined as the difference between the expectations of an outcome under two conditions (the absolute increment) divided by the maximum possible amount for that difference. TRR measures the shift caused by a factor relative to the maximum possible magnitude of that shift. For binary outcomes, TRR simply equals the risk difference, also known as the inverse number needed to treat. TRR ranges from –1 to 1 but is – unlike a correlation coefficient – a measure for effect intensity, because it does not rely on variance parameters in a certain population as do effect size measures (e.g., correlations, Cohen’s d). However, the use of TRR is restricted on outcomes with fixed and meaningful endpoints given, for instance, for meaningful psychological questionnaires or Likert scales. The use of TRR vs. Cohen’s d is illustrated with three examples from Psychological Science 2006 (issues 5 through 8). It is argued that, whenever TRR applies, it should complement Cohen’s d to avoid the problems related to the latter. In any case, the absolute increment should complement d.

Polygenic Risk Score for Smoking is associated with Externalizing Psychopathology and Disinhibited Personality Traits but not Internalizing Psychopathology in Adolescence

2020 ◽  
Author(s):  
Brian M. Hicks ◽  
D. Angus Clark ◽  
Joseph D. Deak ◽  
Mengzhen Liu ◽  
C. Emily Durbin ◽  
...  
Keyword(s):  
Personality Traits ◽  
Genetic Risk ◽  
Behavioral Control ◽  
Cumulative Exposure ◽  
Genetic Influences ◽  
Behavioral Disinhibition ◽  
Polygenic Risk ◽  
Externalizing Psychopathology ◽  
Internalizing Psychopathology ◽  
Random Intercept

Importance: Large consortia of genome wide association studies have yielded more accurate polygenic risk scores (PRS) that aggregate the small effects of many genetic variants to characterize the genetic architecture of disorders and provide a personalized measure of genetic risk. Objective: We examined whether a PRS for smoking measured genetic risk for general behavioral disinhibition by estimating its associations with externalizing and internalizing psychopathology and related personality traits. We examined these associations at multiple time points in adolescence using more refined phenotypes defined by stable characteristics across time and at young ages, which reduced potential confounds associated with cumulative exposure to substances and reverse causality. Methods: Random intercept panel models were fit to symptoms of conduct disorder, oppositional defiant disorder, major depressive disorder (MDD), and teacher ratings of externalizing and internalizing problems and personality traits at ages 11, 14, and 17 years-old in the Minnesota Twin Family Study (N = 3225). Results: The smoking PRS had strong associations with the random intercept factors for all the externalizing measures (mean standardized ꞵ = .27), agreeableness (ꞵ=-.22, 95% CI: -.28, -.16), and conscientiousness (ꞵ=-.19, 95% CI: -.24, -.13), but was not significantly associated with the internalizing measures (mean ꞵ = .06) or extraversion (ꞵ=.01, 95% CI: -.05, .07). After controlling for smoking at age 17, the associations with the externalizing measures (mean ꞵ = .13) and personality traits related to behavioral control (mean ꞵ = -.10) remained statistically significant. Conclusions and Relevance: The smoking PRS measures genetic influences that contribute to a spectrum of phenotypes related to behavioral disinhibition including externalizing psychopathology and normal-range personality traits related to behavioral control, but not internalizing psychopathology. Continuing to identify the correlates and delineate the mechanisms of the genetic influences associated with disinhibition could have substantial impact in mitigating a variety of public health problems (e.g., mental health, academic achievement, criminality).

Sociodemographic inequalities in lifetime treatment seeking and receipt for common mental health problems

2020 ◽  
Author(s):  
Christopher Rayner ◽  
Jonathan Richard Iain Coleman ◽  
Kirstin Lee Purves ◽  
Ewan Carr ◽  
Rosa Cheesman ◽  
...  
Keyword(s):  
Depressive Disorders ◽  
Mental Health Problems ◽  
Sociodemographic Factors ◽  
Treatment Seeking ◽  
Binary Outcomes ◽  
Treatment Access ◽  
Sociodemographic Correlates ◽  
Common Mental Health Problems ◽  
Poor Outcomes ◽  
Lifetime Treatment

Background: Anxiety and depressive disorders can be chronic and disabling, and are associated with poor outcomes. Whilst there are effective treatments, access to these is variable and only a fraction of those in need receive treatment. Aims: The primary aim was to investigate sociodemographic correlates of lifetime treatment access and unpick the relationships between socioeconomic features and treatment inequalities. As such, we aimed to identify groups at greatest risk of never accessing treatment and targets for intervention. Methods: We tested for sociodemographic factors associated with treatment access in UK Biobank participants with lifetime generalised anxiety or major depressive disorder, performing multivariable logistic regressions on two binary outcomes: treatment-seeking (n=33,704) and treatment receipt (n=28,940). Results: Treatment access was less likely in those who were male, from a UK ethnic minority background and who self-medicated with alcohol or drugs. Treatment access was more likely in those who reported use of self-help strategies, with lower income (<£30,000) and greater neighbourhood deprivation, as well as those with a university degree. Conclusion: This work on lifetime treatment seeking and receipt replicates known correlates of treatment receipt during time of treatment need. Our focus on treatment-seeking and receipt highlights two targets for improving treatment access. More work is required to understand the psychosocial barriers to treatment, which mediate the associations observed here.

Characteristics of frequent paediatric users of emergency departments in England: an observational study using routine national data

2020 ◽  
pp. emermed-2019-209122
Author(s):  
Geva Greenfield ◽  
Mitch Blair ◽  
Paul P Aylin ◽  
Sonia Saxena ◽  
Azeem Majeed ◽  
...  
Keyword(s):  
Ethnic Groups ◽  
Emergency Departments ◽  
National Data ◽  
Frequent User ◽  
Frequent Users ◽  
Frequent Attender ◽  
Random Intercept ◽  
Frequent Attendance ◽  
Lower Likelihood ◽  
Deprived Areas

BackgroundFrequent attendances of the same users in emergency departments (ED) can intensify workload pressures and are common among children, yet little is known about the characteristics of paediatric frequent users in EDs.AimTo describe the volume of frequent paediatric attendance in England and the demographics of frequent paediatric ED users in English hospitals.MethodWe analysed the Hospital Episode Statistics dataset for April 2014–March 2017. The study included 2 308 816 children under 16 years old who attended an ED at least once. Children who attended four times or more in 2015/2016 were classified as frequent users. The preceding and subsequent years were used to capture attendances bordering with the current year. We used a mixed effects logistic regression with a random intercept to predict the odds of being a frequent user in children from different sociodemographic groups.ResultsOne in 11 children (9.1%) who attended an ED attended four times or more in a year. Infants had a greater likelihood of being a frequent attender (OR 3.24, 95% CI 3.19 to 3.30 vs 5 to 9 years old). Children from more deprived areas had a greater likelihood of being a frequent attender (OR 1.57, 95% CI 1.54 to 1.59 vs least deprived). Boys had a slightly greater likelihood than girls (OR 1.05, 95% CI 1.04 to 1.06). Children of Asian and mixed ethnic groups were more likely to be frequent users than those from white ethnic groups, while children from black and 'other' had a lower likelihood (OR 1.03, 95% CI 1.01 to 1.05; OR 1.04, 95% CI 1.01 to 1.06; OR 0.88, 95% CI 0.86 to 0.90; OR 0.90, 95% CI 0.87 to 0.92, respectively).ConclusionOne in 11 children was a frequent attender. Interventions for reducing paediatric frequent attendance need to target infants and families living in deprived areas.

scholarly journals Running barefoot leads to lower running stability compared to shod running - results from a randomized controlled study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karsten Hollander ◽  
Daniel Hamacher ◽  
Astrid Zech
Keyword(s):  
Controlled Trial ◽  
Drop Out ◽  
Treadmill Running ◽  
Measurement Unit ◽  
Controlled Study ◽  
Local Dynamic ◽  
Long Term Effects ◽  
Barefoot Running ◽  
Random Intercept ◽  
Short Time

AbstractLocal dynamic running stability is the ability of a dynamic system to compensate for small perturbations during running. While the immediate effects of footwear on running biomechanics are frequently investigated, no research has studied the long-term effects of barefoot vs. shod running on local dynamic running stability. In this randomized single-blinded controlled trial, young adults novice to barefoot running were randomly allocated to a barefoot or a cushioned footwear running group. Over an 8-week-period, both groups performed a weekly 15-min treadmill running intervention in the allocated condition at 70% of their VO2 max velocity. During each session, an inertial measurement unit on the tibia recorded kinematic data (angular velocity) which was used to determine the short-time largest Lyapunov exponents as a measure of local dynamic running stability. One hundred running gait cycles at the beginning, middle, and end of each running session were analysed using one mixed linear multilevel random intercept model. Of the 41 included participants (48.8% females), 37 completed the study (drop-out = 9.7%). Participants in the barefoot running group exhibited lower running stability than in the shod running group (p = 0.037) with no changes during the intervention period (p = 0.997). Within a single session, running stability decreased over the course of the 15-min run (p = 0.012) without differences between both groups (p = 0.060). Changing from shod to barefoot running reduces running stability not only in the acute phase but also in the longer term. While running stability is a relatively new concept, it enables further insight into the biomechanical influence of footwear.

scholarly journals Endocannabinoid system mediates the association between gut-microbial diversity and anhedonia/amotivation in a general population cohort

2021 ◽  
Author(s):  
Amedeo Minichino ◽  
Matthew A. Jackson ◽  
Marta Francesconi ◽  
Claire J. Steves ◽  
Cristina Menni ◽  
...  
Keyword(s):  
General Population ◽  
Microbial Diversity ◽  
Gut Microbiome ◽  
Endocannabinoid System ◽  
Alpha Diversity ◽  
Serum Levels ◽  
Population Cohort ◽  
Random Intercept ◽  
General Population Cohort ◽  
Antidepressant Use

AbstractAnhedonia and amotivation are debilitating symptoms and represent unmet therapeutic needs in a range of clinical conditions. The gut-microbiome-endocannabinoid axis might represent a potential modifiable target for interventions. Based on results obtained from animal models, we tested the hypothesis that the endocannabinoid system mediates the association between gut-microbiome diversity and anhedonia/amotivation in a general population cohort. We used longitudinal data collected from 786 volunteer twins recruited as part the TwinsUK register. Our hypothesis was tested with a multilevel mediation model using family structure as random intercept. The model was set using alpha diversity (within-individual gut-microbial diversity) as predictor, serum and faecal levels of the endocannabinoid palmitoylethanolamide (PEA) as mediator, and anhedonia/amotivation as outcome. PEA is considered the endogenous equivalent of cannabidiol, with increased serum levels believed to have anti-depressive effects, while increased stool PEA levels, reflecting increased excretion, are believed to have opposite, detrimental, effects on mental health. We therefore expected that either reduced serum PEA or increased stool PEA would mediate the association between microbial diversity and anhedonia amotivation. Analyses were adjusted for obesity, diet, antidepressant use, sociodemographic and technical covariates. Data were imputed using multiple imputation by chained equations. Mean age was 65.2 ± 7.6; 93% of the sample were females. We found a direct, significant, association between alpha diversity and anhedonia/amotivation (β = −0.37; 95%CI: −0.71 to −0.03; P = 0.03). Faecal, but not serum, levels of the endocannabinoid palmitoylethanolamide (PEA) mediated this association: the indirect effect was significant (β = −0.13; 95%CI: −0.24 to −0.01; P = 0.03), as was the total effect (β = −0.38; 95%CI: −0.72 to −0.04; P = 0.03), whereas the direct effect of alpha diversity on anhedonia/amotivation was attenuated fully (β = −0.25; 95%CI: −0.60 to 0.09; P = 0.16). Our results suggest that gut-microbial diversity might contribute to anhedonia/amotivation via the endocannabinoid system. These findings shed light on the biological underpinnings of anhedonia/amotivation and suggest the gut microbiota-endocannabinoid axis as a promising therapeutic target in an area of unmet clinical need.

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