Goodness-of-fit measures of R 2 for repeated measures mixed effect models

2008 ◽  
Vol 35 (10) ◽  
pp. 1081-1092 ◽  
Author(s):  
Honghu Liu ◽  
Yan Zheng ◽  
Jie Shen
Keyword(s):  
Repeated Measures ◽  
Goodness Of Fit ◽  
Mixed Effect ◽  
Mixed Effect Models

scholarly journals Changes in dietary patterns from preconception to during pregnancy and its association with socio-demographic and lifestyle factors

2021 ◽  
pp. 1-27
Author(s):  
Dereje G. Gete ◽  
Michael Waller ◽  
Gita D. Mishra
Keyword(s):  
Dietary Patterns ◽  
Repeated Measures ◽  
Educational Status ◽  
Population Based ◽  
Single Women ◽  
Lifestyle Factors ◽  
Healthy Eating Index ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Traditional Vegetable

Abstracts Objective: To examine dietary patterns changes from preconception to during pregnancy and their associations with socio-demographic and lifestyle factors. Design: This study used data from the Australian Longitudinal Study on Women’s Health (ALSWH), a population-based prospective cohort study. Women’s dietary patterns were assessed using Healthy Eating Index-2015 (HEI-2015) score and the four patterns obtained from the factor analysis (Western diets; vegetable and grains; traditional vegetable; and fruit patterns). Multivariable linear regression and repeated measures mixed-effect models were used. Setting: A national representative survey which covers all Australian citizens and permanent residents in Australia. Participants: 621 women were included from the ALSWH. Results: Women’s scores increased on the ‘HEI-2015’, ‘traditional vegetable’, and ‘fruit’ patterns while the ‘vegetable and grains’ decreased from preconception to during pregnancy. Women with higher education were more likely to increase their HEI-2015 score and fruit consumption from preconception to during pregnancy respectively (β= 2.31, 95%CI: 0.02, 4.60) and (β= 23.78, 95%CI: 4.58, 42.97), than those with lower educational status. Single women were more likely to increase the consumption of vegetables and grains compared to married women (β= 76.08, 95% CI: 20.83, 131.32). Women with higher income had a greater increase in the HEI-2015 score than those with lower income (β= 3.02, 95% CI: 0.21, 5.83). Conclusion: The findings indicate that there have been marked dietary changes from preconception to during pregnancy. Changes in healthy dietary patterns were influenced by education, marital status, and income.

scholarly journals Inter-Individual Differences Explain More Variance in Conditioned Pain Modulation Than Age, Sex and Conditioning Stimulus Intensity Combined

2021 ◽  
Vol 11 (9) ◽  
pp. 1186
Author(s):  
Philipp Graeff ◽  
Alina Itter ◽  
Katharina Wach ◽  
Ruth Ruscheweyh
Keyword(s):  
Individual Differences ◽  
Pain Intensity ◽  
Repeated Measures ◽  
Conditioning Stimulus ◽  
Pain Modulation ◽  
Conditioned Pain Modulation ◽  
Cross Sectional ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Endogenous Pain Modulation

Conditioned pain modulation (CPM) describes the reduction in pain evoked by a test stimulus (TS) when presented together with a heterotopic painful conditioning stimulus (CS). CPM has been proposed to reflect inter-individual differences in endogenous pain modulation, which may predict susceptibility for acute and chronic pain. Here, we aimed to estimate the relative variance in CPM explained by inter-individual differences compared to age, sex, and CS physical and pain intensity. We constructed linear and mixed effect models on pooled data from 171 participants of several studies, of which 97 had repeated measures. Cross-sectional analyses showed no significant effect of age, sex or CS intensity. Repeated measures analyses revealed a significant effect of CS physical intensity (p = 0.002) but not CS pain intensity (p = 0.159). Variance decomposition showed that inter-individual differences accounted for 24% to 34% of the variance in CPM while age, sex, and CS intensity together explained <3% to 12%. In conclusion, the variance in CPM explained by inter-individual differences largely exceeds that of commonly considered factors such as age, sex and CS intensity. This may explain why predictive capability of these factors has had conflicting results and suggests that future models investigating them should account for inter-individual differences.

scholarly journals A hierarchical bivariate meta-analysis of diagnostic test accuracy to provide direct comparisons of immunoassays vs. indirect immunofluorescence for initial screening of connective tissue diseases

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michelle Elaine Orme ◽  
Carmen Andalucia ◽  
Sigrid Sjölander ◽  
Xavier Bossuyt
Keyword(s):  
Connective Tissue ◽  
Indirect Immunofluorescence ◽  
Meta Analysis ◽  
Connective Tissue Diseases ◽  
Test Accuracy ◽  
Initial Screening ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Mixed Effect ◽  
Mixed Effect Models

AbstractObjectivesTo compare indirect immunofluorescence (IIF) for antinuclear antibodies (ANA) against immunoassays (IAs) as an initial screening test for connective tissue diseases (CTDs).MethodsA systematic literature review identified cross-sectional or case-control studies reporting test accuracy data for IIF and enzyme-linked immunosorbent assays (ELISA), fluorescence enzyme immunoassay (FEIA), chemiluminescent immunoassay (CLIA) or multiplex immunoassay (MIA). The meta-analysis used hierarchical, bivariate, mixed-effect models with random-effects by test.ResultsDirect comparisons of IIF with ELISA showed that both tests had good sensitivity (five studies, 2321 patients: ELISA: 90.3% [95% confidence interval (CI): 80.5%, 95.5%] vs. IIF at a cut-off of 1:80: 86.8% [95% CI: 81.8%, 90.6%]; p = 0.4) but low specificity, with considerable variance across assays (ELISA: 56.9% [95% CI: 40.9%, 71.5%] vs. IIF 1:80: 68.0% [95% CI: 39.5%, 87.4%]; p = 0.5). FEIA sensitivity was lower than IIF sensitivity (1:80: p = 0.005; 1:160: p = 0.051); however, FEIA specificity was higher (seven studies, n = 12,311, FEIA 93.6% [95% CI: 89.9%, 96.0%] vs. IIF 1:80 72.4% [95% CI: 62.2%, 80.7%]; p < 0.001; seven studies, n = 3251, FEIA 93.5% [95% CI: 91.1%, 95.3%] vs. IIF 1:160 81.1% [95% CI: 73.4%, 86.9%]; p < 0.0001). CLIA sensitivity was similar to IIF (1:80) with higher specificity (four studies, n = 1981: sensitivity 85.9% [95% CI: 64.7%, 95.3%]; p = 0.86; specificity 86.1% [95% CI: 78.3%, 91.4%]). More data are needed to make firm inferences for CLIA vs. IIF given the wide prediction region. There were too few studies for the meta-analysis of MIA vs. IIF (MIA sensitivity range 73.7%–86%; specificity 53%–91%).ConclusionsFEIA and CLIA have good specificity compared to IIF. A positive FEIA or CLIA test is useful to support the diagnosis of a CTD. A negative IIF test is useful to exclude a CTD.

scholarly journals Neurophysiological and behavioural effects of conventional and high definition tDCS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabio Masina ◽  
Giorgio Arcara ◽  
Eleonora Galletti ◽  
Isabella Cinque ◽  
Luciano Gamberini ◽  
...  
Keyword(s):  
Response Times ◽  
Power Reduction ◽  
Alpha Power ◽  
High Definition ◽  
Mixed Effect ◽  
State Dependency ◽  
Mixed Effect Models ◽  
Beta Power ◽  
Neurophysiological Data ◽  
Spectrum Density

AbstractHigh-definition transcranial direct current stimulation (HD-tDCS) seems to overcome a drawback of traditional bipolar tDCS: the wide-spread diffusion of the electric field. Nevertheless, most of the differences that characterise the two techniques are based on mathematical simulations and not on real, behavioural and neurophysiological, data. The study aims to compare a widespread tDCS montage (i.e., a Conventional bipolar montage with extracephalic return electrode) and HD-tDCS, investigating differences both at a behavioural level, in terms of dexterity performance, and a neurophysiological level, as modifications of alpha and beta power as measured with EEG. Thirty participants took part in three sessions, one for each montage: Conventional tDCS, HD-tDCS, and sham. In all the conditions, the anode was placed over C4, while the cathode/s placed according to the montage. At baseline, during, and after each stimulation condition, dexterity was assessed with a Finger Tapping Task. In addition, resting-state EEG was recorded at baseline and after the stimulation. Power spectrum density was calculated, selecting two frequency bands: alpha (8–12 Hz) and beta (18–22 Hz). Linear mixed effect models (LMMs) were used to analyse the modulation induced by tDCS. To evaluate differences among the montages and consider state-dependency phenomenon, the post-stimulation measurements were covariate-adjusted for baseline levels. We observed that HD-tDCS induced an alpha power reduction in participants with lower alpha at baseline. Conversely, Conventional tDCS induced a beta power reduction in participants with higher beta at baseline. Furthermore, data showed a trend towards a behavioural effect of HD-tDCS in participants with lower beta at baseline showing faster response times. Conventional and HD-tDCS distinctively modulated cortical activity. The study highlights the importance of considering state-dependency to determine the effects of tDCS on individuals.

scholarly journals Recombining Your Way Out of Trouble: The Genetic Architecture of Hybrid Fitness under Environmental Stress

2019 ◽  
Vol 37 (1) ◽  
pp. 167-182 ◽  
Author(s):  
Zebin Zhang ◽  
Devin P Bendixsen ◽  
Thijs Janzen ◽  
Arne W Nolte ◽  
Duncan Greig ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Evolutionary Potential ◽  
Genetic Trait ◽  
Hybrid Fitness ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Hybrid Genome ◽  
Chromosome Associations ◽  
Low Coverage ◽  
Negative Epistasis

Abstract Hybridization between species can either promote or impede adaptation. But we know very little about the genetic basis of hybrid fitness, especially in nondomesticated organisms, and when populations are facing environmental stress. We made genetically variable F2 hybrid populations from two divergent Saccharomyces yeast species. We exposed populations to ten toxins and sequenced the most resilient hybrids on low coverage using ddRADseq to investigate four aspects of their genomes: 1) hybridity, 2) interspecific heterozygosity, 3) epistasis (positive or negative associations between nonhomologous chromosomes), and 4) ploidy. We used linear mixed-effect models and simulations to measure to which extent hybrid genome composition was contingent on the environment. Genomes grown in different environments varied in every aspect of hybridness measured, revealing strong genotype–environment interactions. We also found selection against heterozygosity or directional selection for one of the parental alleles, with larger fitness of genomes carrying more homozygous allelic combinations in an otherwise hybrid genomic background. In addition, individual chromosomes and chromosomal interactions showed significant species biases and pervasive aneuploidies. Against our expectations, we observed multiple beneficial, opposite-species chromosome associations, confirmed by epistasis- and selection-free computer simulations, which is surprising given the large divergence of parental genomes (∼15%). Together, these results suggest that successful, stress-resilient hybrid genomes can be assembled from the best features of both parents without paying high costs of negative epistasis. This illustrates the importance of measuring genetic trait architecture in an environmental context when determining the evolutionary potential of genetically diverse hybrid populations.

Association of fine particulate matter with glucose and lipid metabolism: a longitudinal study in young adults

2021 ◽  
pp. oemed-2020-107039
Author(s):  
Jingyi Qin ◽  
Wei Xia ◽  
Gaodao Liang ◽  
Shunqing Xu ◽  
Xiuge Zhao ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Lipid Metabolism ◽  
Longitudinal Study ◽  
Fine Particulate Matter ◽  
Healthy Adults ◽  
Mixed Effect ◽  
Glucose And Lipid Metabolism ◽  
Mixed Effect Models ◽  
Fine Particulate ◽  
Linear Mixed Effect Models

ObjectivesThis study aimed to evaluate whether PM2.5 exposure in a highly polluted area (>100 µg/m3) affects glucose and lipid metabolism in healthy adults.MethodsWe recruited 110 healthy adults in Baoding city, Hebei, China, and followed them up between 2017 and 2018. Personal air samplers were used to monitor personal PM2.5 levels. Eight glucose and lipid metabolism parameters were quantified. We performed the linear mixed-effect models to investigate the relationships between PM2.5 and glucose and lipid metabolism parameters. Stratified analyses were further performed according to sex and body mass index (BMI).ResultsThe concentration of PM2.5 was the highest in spring, with a median of 232 μg/m3 and the lowest in autumn (139 μg/m3). After adjusting for potential confounders, we found that for each twofold increase in PM2.5, the median of insulin concentration decreased by 5.89% (95% CI −10.91% to −0.58%; p<0.05), and ox-LDL increased by 6.43% (95% CI 2.21% to 10.82%; p<0.05). Stratified analyses indicated that the associations were more pronounced in females, overweight and obese participants.ConclusionsExposure to high PM2.5 may have deleterious effects on glucose and lipid metabolism. Females, overweight and obese participants are more vulnerable.

scholarly journals Prospective study of vitrectomy for epiretinal membranes in patients with good best-corrected visual acuity

2019 ◽  
Author(s):  
Hiroyuki Nakashizuka ◽  
Yorihisa Kitagawa ◽  
Yu Wakatsuki ◽  
Koji Tanaka ◽  
Koichi Furuya ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Foveal Thickness ◽  
Mixed Effect ◽  
Epiretinal Membranes ◽  
Central Foveal Thickness ◽  
Mixed Effect Models ◽  
Corrected Visual Acuity ◽  
Good Group ◽  
Final Observation ◽  
Best Corrected Visual Acuity

Abstract Purpose: To evaluate the efficacy of epiretinal membrane removal in patients with good best-corrected visual acuity (BCVA) for improving visual function and quality of life (QOL). Methods: This prospective case study compared 37 subjects with preoperative BCVA≦logMAR0.046 (Good group) to 35 patients with logMAR BCVA 0.52–0.10 (Moderate group) at 3 and 6 months. Linear mixed-effect models were used for statistical analysis. The primary outcome was the horizontal metamorphopsia score (MH) at 6 months postoperatively (post-6 M), while secondary outcomes were postoperative BCVA, vertical metamorphopsia score (MV), aniseikonia, stereopsis and central foveal thickness. In the Good group, QOL was assessed using the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) at 6 and 12 months. Results: MH was significantly improved at post-3 M and post-6 M in the both groups but there were no significant differences between the two groups. MV showed no improvement at the final observation in either group. LogMAR BCVA was significantly improved at post-6 M in the Good group, which had significantly better vision than the Moderate group. Preoperative vertical and horizontal aniseikonia scores remained unchanged in the Good group at post-6 M but worsened in the Moderate group. The NEI VFQ-25 score improved in the Good group, reflecting improved general health, general vision, and mental health. Conclusions: Early epiretinal surgery was effective for MH, BCVA, aniseikonia, and QOL.

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