Development of a new modified hogg type adaptive scheme for multilevel models with diverse error distributions

Author(s):  
Sehar Saleem ◽  
Rehan Ahmad Khan Sherwani ◽  
Muhammad Amin
Methodology ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 95-108 ◽  
Author(s):  
Steffen Nestler ◽  
Katharina Geukes ◽  
Mitja D. Back

Abstract. The mixed-effects location scale model is an extension of a multilevel model for longitudinal data. It allows covariates to affect both the within-subject variance and the between-subject variance (i.e., the intercept variance) beyond their influence on the means. Typically, the model is applied to two-level data (e.g., the repeated measurements of persons), although researchers are often faced with three-level data (e.g., the repeated measurements of persons within specific situations). Here, we describe an extension of the two-level mixed-effects location scale model to such three-level data. Furthermore, we show how the suggested model can be estimated with Bayesian software, and we present the results of a small simulation study that was conducted to investigate the statistical properties of the suggested approach. Finally, we illustrate the approach by presenting an example from a psychological study that employed ecological momentary assessment.


2020 ◽  
Author(s):  
Matthew Wade ◽  
Nicola Brown ◽  
James Steele ◽  
Steven Mann ◽  
Bernadette Dancy ◽  
...  

Background: Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental wellbeing after a motivational interviewing (MI) community-based PA intervention and the impact of signposting [SP] and Social Action [SA] (i.e. weekly group support) pathways. Methods: Participants (n=2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental wellbeing data were collected at baseline (following an initial 30-minute MI appointment), 12-weeks, six-months, and 12-months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models were used to derive point estimates and 95%CIs for outcomes at each time point and change scores. Results: Participants increased PA and mental wellbeing at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12-weeks, but the SP pathway retained more participants at six-months and 12-months. Conclusions: Both pathways produced similar improvements in PA and mental wellbeing, suggesting the effectiveness of MI based PA interventions. However, due to lower resources required yet similar effects, SP pathways are recommended over SA to support PA in primary care settings.


2019 ◽  
Author(s):  
Rumen Manolov

The lack of consensus regarding the most appropriate analytical techniques for single-case experimental designs data requires justifying the choice of any specific analytical option. The current text mentions some of the arguments, provided by methodologists and statisticians, in favor of several analytical techniques. Additionally, a small-scale literature review is performed in order to explore if and how applied researchers justify the analytical choices that they make. The review suggests that certain practices are not sufficiently explained. In order to improve the reporting regarding the data analytical decisions, it is proposed to choose and justify the data analytical approach prior to gathering the data. As a possible justification for data analysis plan, we propose using as a basis the expected the data pattern (specifically, the expectation about an improving baseline trend and about the immediate or progressive nature of the intervention effect). Although there are multiple alternatives for single-case data analysis, the current text focuses on visual analysis and multilevel models and illustrates an application of these analytical options with real data. User-friendly software is also developed.


2013 ◽  
Vol 34 (8) ◽  
pp. 1980-1985
Author(s):  
Tian-ming Ma ◽  
Yu-song Shi ◽  
Feng-rong Li ◽  
Ying-guan Wang

2020 ◽  
Vol 35 (6) ◽  
pp. 958-958
Author(s):  
Gettens K ◽  
Gorin A

Abstract Objective Executive functions (EF) are crucial to successful weight management, yet few studies have prospectively explored the influence of social-environmental factors on the EF-weight loss (WL) link. This study examined interactions between EF, partner support, and household structure on weight loss outcomes in a couples-based intervention, grounded in Self-Determination Theory (SDT). Method Cohabitating dyads attended weekly weight loss groups (Ncouples = 64), Mage =54.0 ± 9.5, MBMI = 34.2 ± 5.4 kg/m2, 50% female, 88.8% Caucasian). Weight was measured at baseline and 6 months. The Behavior Rating Index of Executive Functions-Adult assessed 9 EF domains; higher scores indicate greater difficulty. Partner autonomy support (AS) was measured using the Important Other Climate Questionnaire, household structure with the Confusion, Hubbub, and Order Scale (CHAOS), IQ with the WASI-II 2-subscale estimate. Results Multilevel models were specified with MIXED linear function in SPSS to account for dyadic interdependence, controlling for age, education, IQ and group. Moderators (AS and CHAOS) were grand-mean centered. High and low levels were created at +1SD and -1SD. At high levels of AS, Shifting (B = 1.50, p = .01) and Inhibition (B = 2.23, p = .01) were associated with greater 6-month WL. At low levels of AS, Working Memory was associated with greater WL (p < .01). Self-Monitoring was associated with greater WL at high chaos (B = .43, p = .01), but not low chaos (p = 0.1). Conclusions Findings suggest that context matters; recruiting specific EFs may promote more WL for individuals embedded in low support or chaotic home environments. Future interventions should address the complexity of successful weight management, targeting both individual and social-interpersonal factors.


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