Multilevel Modeling Approach Research Articles

Influence of a Confined Methanol Solvent on the Reactivity of Active Sites in UiO-66.

UiO‐66, composed of Zr‐oxide bricks and terephthalate linkers, is currently one of the most studied metal–organic frameworks due to its exceptional stability. Defects can be introduced in the structure, creating undercoordinated Zr atoms which are Lewis acid sites. Here, additional Brønsted sites can be generated by coordinated protic species from the solvent. In this Article, a multilevel modeling approach was applied to unravel the effect of a confined methanol solvent on the active sites in UiO‐66. First, active sites were explored with static periodic density functional theory calculations to investigate adsorption of water and methanol. Solvent was then introduced in the pores with grand canonical Monte Carlo simulations, followed by a series of molecular dynamics simulations at operating conditions. A hydrogen‐bonded network of methanol molecules is formed, allowing the protons to shuttle between solvent methanol, adsorbed water, and the inorganic brick. Upon deprotonation of an active site, the methanol solvent aids the transfer of protons and stabilizes charged configurations via hydrogen bonding, which could be crucial in stabilizing reactive intermediates. The multilevel modeling approach adopted here sheds light on the important role of a confined solvent on the active sites in the UiO‐66 material, introducing dynamic acidity in the system at finite temperatures by which protons may be easily shuttled from various positions at the active sites.

Cognitive load predicts point-of-care ultrasound simulator performance.

IntroductionThe ability to maintain good performance with low cognitive load is an important marker of expertise. Incorporating cognitive load measurements in the context of simulation training may help to inform judgements of competence. This exploratory study investigated relationships between demographic markers of expertise, cognitive load measures, and simulator performance in the context of point-of-care ultrasonography.MethodsTwenty-nine medical trainees and clinicians at the University of Toronto with a range of clinical ultrasound experience were recruited. Participants answered a demographic questionnaire then used an ultrasound simulator to perform targeted scanning tasks based on clinical vignettes. Participants were scored on their ability to both acquire and interpret ultrasound images. Cognitive load measures included participant self-report, eye-based physiological indices, and behavioural measures. Data were analyzed using a multilevel linear modelling approach, wherein observations were clustered by participants.ResultsExperienced participants outperformed novice participants on ultrasound image acquisition. Ultrasound image interpretation was comparable between the two groups. Ultrasound image acquisition performance was predicted by level of training, prior ultrasound training, and cognitive load. There was significant convergence between cognitive load measurement techniques. A marginal model of ultrasound image acquisition performance including prior ultrasound training and cognitive load as fixed effects provided the best overall fit for the observed data.DiscussionIn this proof-of-principle study, the combination of demographic and cognitive load measures provided more sensitive metrics to predict ultrasound simulator performance. Performance assessments which include cognitive load can help differentiate between levels of expertise in simulation environments, and may serve as better predictors of skill transfer to clinical practice.Electronic supplementary materialThe online version of this article (10.1007/s40037-017-0392-7) contains supplementary material, which is available to authorized users.

Appreciative Attitudes Toward Jews Among Non-Jewish US College Students

The purpose of this study was to examine appreciative attitudes toward Jews – a historically marginalized and targeted worldview identity group in the context of American higher education – among non-Jewish undergraduates. Drawing from a sample of 13,489 students across 52 institutions and using a multilevel modeling approach, we found that appreciative attitudes toward Jews varied by students’ perceptions of structural, psychological and behavioral climate dimensions related to worldview and by students’ identification patterns, including worldview. Of specific interest to Jewish educators, the presence of a Jewish organization on campus was associated with greater appreciative student attitudes toward Jews after controlling for demographic and other institutional covariates.

Vertical distribution of foliar biomass in western larch (Larix occidentalis)

Western larch (Larix occidentalis Nutt.) is an endemic pioneer species in northwestern North America and unique as a deciduous conifer and the most shade-intolerant, fastest growing, and most fire-resistant species in the northwestern United States. To better understand its production ecology, we used a multilevel modeling approach to analyze the intrinsic dynamics of western larch vertical foliage distribution and compared it with other species. We found that western larch allocates foliage into a more diffuse distribution as the crown lengthens, whereas shade-tolerant evergreens concentrate foliage into a more monolayered distribution higher within the crown as it lengthens. Crown foliar biomass scaled linearly with diameter at breast height, indicating that western larch does not fill volume in the crown with foliage at an increasing rate like other conifers. Our model supports the hypothesis that foliar shade intolerance and water stress jointly influence foliage allocation in this deciduous conifer. These results also highlight intrinsic foliage distribution as a factor potentially contributing to the inability of western larch to survive light-limiting conditions and its preference for mesic sites. The models developed here provide a basic framework that may be built upon to study the morphological response of western larch to modified stand conditions such as disturbance and silvicultural treatment.

Epidemiology of Clostridium Difficile Infection in a Large Hospital in Northern Italy: Questioning the Ward-Based Transmission.

Background: Clostridium Difficile infection (CDI) is considered a ward-based nosocomial infection, due to contagion among patients. Molecular studies recently questioned ward-based contact for disease spread.Objective:To investigate whether it is plausible that CDI spread in San Martino Hospital of Genoa was due to a ward-based contact and patient-to-patient diffusion.Methods:We conducted a retrospective cohort study of CDI cases from April 2010 to March 2015. We referred to Hospital data set and Admission Service. Multilevel modelling approach and ecological analysis were used to assess C. difficile infection risk according to wards and time of occurrence. Six representative CD strains were ribotyped to assess a possible equivalence.Results:The assessment of 514 CDI cases showed that the risk of disease and rate of incidence in wards were independent, while frequency of cases and number of wards involved exhibited a positive relationship, excluding the typical epidemic pattern of contagious diffusion, i.e., many cases in few wards. The extra-binomial variability due to ward clustering was not significant, indicating homogeneity in the probability of CDI occurrence across all wards. Three hundred sixty-eight patients changed ward, without showing connection between the frequency of cases in new wards and incidence among new subjects. Trigonometric components described a significant contribution of seasonality, with excess of CDI cases during the winter months. Molecular analysis showed different ribotypes of CD strains from the same ward.Conclusion:From our results it seems unlikely that in our institution CDI occurrence is due to ward-based contact and inter-human contagion of the organism.

Correlates of burnout symptoms among child care teachers. A multilevel modeling approach

ABSTRACTBurnout is a widespread occupational stress outcome among child care teachers, jeopardizing the quality of care and children’s development. This study aimed at exploring the relationships between individual and organizational level characteristics (representing the six work-life areas control, reward, workload, community, fairness, and values) and burnout levels because these nested associations are an overlooked area. We applied a mixed-effects model with data at the individual level (level 1) and child care center level (level 2) using assessments of 220 child care teachers and their 59 directors of 59 child care centers in a Swiss community. We found that the child care center mattered for the experienced burnout levels and that lower control and reward on level 1 and higher workload on level 2 were associated with higher burnout levels among child care teachers. These results suggest the need to target the individual and the organizational levels to tackle burnout symptoms.

Approaches for Specifying the Level-1 Error Structure When Synthesizing Single-Case Data

ABSTRACTMultilevel modeling has been utilized for combining single-case experimental design (SCED) data assuming simple level-1 error structures. The purpose of this study is to compare various multilevel analysis approaches for handling potential complexity in the level-1 error structure within SCED data, including approaches assuming simple and complex error structures (heterogeneous, autocorrelation, and both) and those using fit indices to select between alternative error structures. A Monte Carlo study was conducted to empirically validate the suggested multilevel modeling approaches. Results indicate that each approach leads to fixed effect estimates with little to no bias and that inferences for fixed effects were frequently accurate, particularly when a simple homogeneous level-1 error structure or a first-order autoregressive structure was assumed and the inferences were based on the Kenward-Roger method. Practical implications and recommendations are discussed.

Effect of overlay thickness, overlay material, and pre-overlay treatment on evolution of asphalt concrete overlay roughness in LTPP SPS-5 experiment: A multilevel model approach

The objective of this study is to investigate the effect of overlay thickness, overlay material and pre-overlay treatment on roughness evolution of asphalt overlay in the Long-term Pavement Performance (LTPP) SPS-5 experiment. Roughness data collected from SPS-5 experimental sites has a clustered longitudinal structure. A multilevel model is established to simultaneously account for measurement correlation within the same test section and roughness evolution correlation within the same experimental site. It was discovery that while as-built roughness depends on overlay material and overlay thickness, roughness growth rate only depends on overlay thickness.

Effects of post-abortion family planning services on preventing unintended pregnancy and repeat abortion (INPAC): a cluster randomised controlled trial in 30 Chinese provinces

BackgroundAround 10 million induced abortions are conducted annually in China; a third of the women having had those abortions have undergone repeat abortions. Most abortions are performed in hospital settings in which post-abortion family planning (PAFP) services are often lacking. This study aims to evaluate the effects of integrating PAFP services into abortion services on the reduction of unintended pregnancy and repeat abortion in China. MethodsThis was a three-arm cluster (hospital) randomised controlled trial. Study participants were women undergoing an abortion within 12 weeks of pregnancy. 90 hospitals were selected from 30 Chinese provinces and allocated randomly (1:1) into two intervention groups or one control group. Intervention group 1 included provision of family planning information, contraceptive counselling, involvement of the male partner, and free provision of contraception; intervention group 2 included incentive mechanisms for health-care providers in addition to group 1; and the control group received normal care, with no intervention. Eligible women were followed up for 6 months. The primary outcomes were the rates of unintended pregnancies and repeat induced abortions. We used a three-level random intercept model to estimate the effects of intervention using a generalised linear mixed model, and we used SAS PROC GLIMMIX with maximum likelihood with Laplace approximation to perform this multilevel modelling approach. This study received ethical approval from the Ethical Committees at Ghent University, Belgium, on May 26, 2014 (B670201421116), and from the National Research Institute for Family Planning, China, on March 6, 2014. All participants provided a Chinese written informed consent. This trial has been registered at International Standard Randomised Controlled Trial, number ISRCTN01846583. FindingsWe recruited 17 235 eligible women from July 11, 2014, to Aug 20, 2015. The intervention 1 group included 5856 women, intervention 2 group included 5791 women, and the control group included 5588 women. The proportion of patients who were followed up for up to 6 months were similar in the three groups (74·7% [4372 of 5856] in intervention group 1, 77·1% [4466 of 5791] in intervention group 2, and 75·7% [4231 of 5588] in the control group). The proportion of patients with unintended pregnancy within 6 months after abortion was lower in both intervention groups (1·2% [59 of 5011] in group 1 and 1·2% [58 of 4986] in group 2) than in the control group (3·2% [155 of 4817]). The proportion of patients who had a repeat abortion was 0·9% (45 of 5011) for the intervention group 1, 0·8% (41 of 4986) for the intervention group 2, and 1·6% (77 of 4817) for the control group (ie, 16–38% lower in the interventions group than that in the control group). Statistical analysis is ongoing. InterpretationIntegrating post-abortion family planning services into hospital-based abortion services could decrease unintended pregnancy and repeat abortions. A policy and guidelines on integration of PAFP into routine abortion services is urgently needed to reduce the number of abortions. FundingEuropean Commission FP7 (282490).

Age, sex, qualifications and voting at recent English general elections: an alternative exploratory approach

There has been a substantial switch in approaches to the study of British voting behaviour in recent decades, with much less attention being paid to individual voters' social positions. This paper argues that such approaches can mis-represent the contexts within which voters are socialised and mobilised and are also technically problematic because social positions and attitudes may well be collinear – in which case ‘true’ relationships are difficult to uncover. Further, regression models that include variables representing social positions almost invariably look at the main effects only and pay no attention to the interactions among those variables. Using a newly-developed multilevel modelling approach to the analysis of multi-way contingency tables, this paper explores the relationships between respondents' age, sex and qualifications and their voting at three recent general elections in England, using a large data set. It indicates that, contrary to recent work, respondents' social positions are linked – through their attitudes – to their partisan choices, and that exploration of the interactions among those variables identifies important differences in how they voted.

Proinflammatory Dietary Intake is Associated with Increased Risk of Colorectal Cancer: Results of a Case-Control Study in Argentina Using a Multilevel Modeling Approach

ABSTRACTLittle evidence regarding the inflammatory potential of diet and its effect on colorectal cancer exists in Latin American countries. The aim of the present study was to evaluate the association between the Dietary Inflammatory Index (DII®) and colorectal cancer (CRC) risk in Córdoba, Argentina. A frequency-matched case-control study (N = 446, including 144 (32.3%) CRC cases and 302 (67.7%) controls was conducted in Córdoba (Argentina) from 2008 through 2015. DII® scores were computed based on dietary intake assessed by a validated food frequency questionnaire (FFQ). Multilevel logistic regression models were fit to evaluate the association between DII scores and CRC, following adjustment for age, body mass index, sex, energy intake, smoking habits, socio-economic status, physical activity, and use of nonsteroidal anti-inflammatory drugs as first-level covariates and level of urbanization as the contextual variable. Odds of colorectal cancer increased linearly with increasing DII scores (ORcontinuous 1.34; 95%CI 1.07 to 1.69 and ORtertile3 vs. tertile1 1.21; 95%CI 1.01 to 1.44). The association was stronger among men than women (ORcontinuous 1.29; 95%CI 1.21 to 1.37 vs. ORcontinuous 1.05; 95%CI 0.83 to 1.33, respectively). A proinflammatory diet, reflected by higher DII scores, was positively associated with colorectal cancer occurrence, mainly in men.

Estimating Educational Differences in Low-Risk Cesarean Section Delivery: A Multilevel Modeling Approach

U.S. rates of cesarean section, and in particular, low-risk cesarean section (LRC) births rose dramatically across the late 1990s and early 2000s, and have since remained high. Although previous research explores how trends in LRC vary between states and across maternal characteristics, within-state heterogeneity has not yet been accounted for, nor has the extent to which maternal and county characteristics might interact to shape the likelihood of a LRC birth. Using U.S. county-level birth data for years 2008–2010 from the restricted National Vital Statistics Systems Cohort Linked Birth-Infant Death Files and the Area Health Resource Files, I conduct race-stratified multilevel analyses to explore the association between the mother’s education, the income of the county in which she gives birth, and the odds of LRC delivery. I find that regardless of race/ethnicity, less education at the individual level and lower income at the county level are associated with higher odds of LRC delivery. There are also persistent racial disparities in these relationships. Non-Hispanic black mothers have the highest overall odds of LRC delivery, yet the effect of both education and county income is greatest for non-Hispanic white mothers. The results highlight the importance of analyzing both individual resources and contextual effects of the county when assessing birthing processes, as both contribute to a mother’s access to and knowledge of natal care.

Effects of additional capacity on vehicle kilometers of travel in the U.S.: Evidence from National Household Travel Surveys

Adding capacity is one policy mechanism to alleviate congestion. However, the empirical evidence strongly suggests that additional capacity only makes congestion worse. This study analyzes the differential effects of additional freeway capacity versus additional arterial capacity on vehicle kilometers of travel (VKT) in metropolitan areas across the U.S. The analysis uses vehicle data and household data from the 2001 and the 2009 National Household Travel Surveys (NHTS) and includes stock and flow measures of road capacity, road congestion, commuter demand, and economic growth for metropolitan areas. Taking into account differences between metropolitan areas on each measure, the study adopts a novel multilevel model approach to estimate how additional capacity affects VKT. Results indicate that adding more arterial capacity slightly decreases VKT over a lag period from six years (1995 to 2001) to eight years (2001 to 2009), probably because adding arterials shortens routes between origins and destinations more so than adding freeways. Consistent with expectations, VKT is lower in more congested metropolitan areas, and in metropolitan areas that got more congested. Results also indicate that rebound effects (higher fuel-economy vehicles are driven much more than lower fuel-economy vehicles) will at least partially offset the demand management benefits of (gasoline) price sensitivity (higher gasoline prices decrease VKT).

Internal versus external service quality: reflections of employees and customers in the mirror

Introduction: The purpose of this study to investigate internal service quality (as perceived by employees) and external (customer) perceptions of quality in the context of service profit chain (SPC).Objective: The objective of the study is to evaluate the impact of internal service quality on students’ perceptions of quality and to test the significance of a direct link between internal and external service quality.Methods: We measured the perceived service quality using a SERVPERF instrument and the multilevel modeling approach with HLM 7.01.Results: The empirical findings support a link between perceptions of internal and external service quality. We show that when employees (faculty) perceive university services as being of high quality, it has a positive spill-over effect on students’ overallperceptions of the quality of university services. Perceptions of internal service quality are also positively related to students’ perceptions of reliability, responsiveness and quality assurance.Conclusions: The perceptions of internal service quality by faculty members are positively related to students’ perceptions of quality. Comparing the levels of internal and external service quality will help managers define priorities for allocating resources to improve quality.

Evaluation design of Urban Health Centres Europe (UHCE): preventive integrated health and social care for community-dwelling older persons in five European cities

BackgroundOlder persons often have interacting physical and social problems and complex care needs. An integrated care approach in the local context with collaborations between community-, social-, and health-focused organisations can contribute to the promotion of independent living and quality of life. In the Urban Health Centres Europe (UHCE) project, five European cities (Greater Manchester, United Kingdom; Pallini (in Greater Athens Area), Greece; Rijeka, Croatia; Rotterdam, the Netherlands; and Valencia, Spain) develop and implement a care template that integrates health and social care and includes a preventive approach. The UHCE project includes an effect and process evaluation.MethodsIn a one-year pre-post controlled trial, in each city 250 participants aged 75+ years are recruited to receive the UHCE approach and are compared with 250 participants who receive ‘care as usual’. Benefits of UHCE approach in terms of healthy life styles, fall risk, appropriate medication use, loneliness level and frailty, and in terms of level of independence and health-related quality of life and health care use are assessed. A multilevel modeling approach is used for the analyses. The process evaluation is used to provide insight into the reach of the target population, the extent to which elements of the UHCE approach are executed as planned and the satisfaction of the participants.DiscussionThe UHCE project will provide new insight into the feasibility and effectiveness of an integrated care approach for older persons in different European settings.Trial registrationISRCTN registry number is ISRCTN52788952. Date of registration is 13/03/2017.

A multilevel modeling approach to examining the implementation-effectiveness relationship of a behavior change intervention for health care professional trainees.

Changing Minds, Changing Lives, a seminar-mediated behavior change intervention, aims to enhance health care professionals' (HCPs') social cognitions for discussing leisure-time physical activity (LTPA) with patients with physical disabilities. This study examines which seminar implementation variables (presenter characteristics, delivery components) predict effectiveness using multilevel modeling. HCP trainees (n=564) attended 24 seminars and completed Theory of Planned Behavior-based measures for discussing LTPA at pre-, post-, 1-month post-, and 6-months post-seminar. Implementation variables were extracted from presenter-completed questionnaires/checklists. Seminars presented by a HCP predicted positive changes in all cognitions pre-post but negative changes in attitudes and perceived behavioral control (PBC) over follow-up (ps<.05). The number of seminars the presenter had delivered predicted negative changes in attitudes and PBC during follow-up (ps<.001). Inclusion of audiovisual components predicted positive changes in attitudes pre-post (p<.001). Presenter characteristics may be "key ingredients" to educational interventions for HCPs; however, future studies should examine additional implementation variables.

Perceptions of caretakers with different socioeconomic status about the harmful outcomes of fever in under-five children in Dodoma region, central Tanzania: A cross-sectional study

BackgroundSocioeconomic status can affect health in childhood through many different pathways. Evidence on how households differ with regard to socioeconomic status and the degree to which this difference is associated with investment in child health is essential to the design of appropriate intervention strategies. AimThis study examines the impact of caretakers’ socio-economic characteristics on perceptions about the harmful outcomes of fever among under-five children. Material and methodsThe study used a three-stage cluster sample of households with under-five children in Dodoma region, central Tanzania. Multilevel modelling approach was used to model the relationship between the outcome measure and caretakers’ socioeconomic characteristics while controlling for other variables. ResultsA total of 329 under-five children with fever were studied of which 74.8% were perceived by their caretakers to have some chances for harmful effects of fever to occur when they experienced fever. Secondary school education or above of caretakers was significantly associated with decreased beliefs about the occurrence of harmful effects of fever. ConclusionMany caretakers are concerned about the occurrence of harmful effects of fever for their under-five children. Study findings suggest that promoting enrolment in secondary education or above and participation in the labour market particularly in non-farm activities of women would be valuable to the health of under-five children in central Tanzania.

Longitudinal associations between exercise identity and exercise motivation: A multilevel growth curve model approach.

Past work linking exercise identity and exercise motivation has been cross-sectional. This is the first study to model the relations between different types of exercise identity and exercise motivation longitudinally. Understanding the dynamic associations between these sets of variables has implications for theory development and applied research. This was a longitudinal survey study. Participants were 180 exercisers (79 men, 101 women) from Greece, who were recruited from fitness centers and were asked to complete questionnaires assessing exercise identity (exercise beliefs and role-identity) and exercise motivation (intrinsic, identified, introjected, external motivation, and amotivation) three times within a 6month period. Multilevel growth curve modeling examined the role of motivational regulations as within- and between-level predictors of exercise identity, and a model in which exercise identity predicted exercise motivation at the within- and between-person levels. Results showed that within-person changes in intrinsic motivation, introjected, and identified regulations were positively and reciprocally related to within-person changes in exercise beliefs; intrinsic motivation was also a positive predictor of within-person changes in role-identity but not vice versa. Between-person differences in the means of predictor variables were predictive of initial levels and average rates of change in the outcome variables. The findings show support to the proposition that a strong exercise identity (particularly exercise beliefs) can foster motivation for behaviors that reinforce this identity. We also demonstrate that such relations can be reciprocal overtime and can depend on the type of motivation in question as well as between-person differences in absolute levels of these variables.

Identifying patient and practice characteristics associated with patient-reported experiences of safety problems and harm: a cross-sectional study using a multilevel modelling approach

ObjectiveTo identify patient and family practice characteristics associated with patient-reported experiences of safety problems and harm.DesignCross-sectional study combining data from the individual postal administration of the validated Patient Reported Experiences...

Prediction of Atherosclerotic Plaque Development in an In Vivo Coronary Arterial Segment Based on a Multilevel Modeling Approach

Prediction of Atherosclerotic Plaque Development in an In Vivo Coronary Arterial Segment Based on a Multilevel Modeling Approach