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Nevin Manimala Statistics

Multivariate Generalized Linear Models for Twin and Family Data

Behav Genet. 2022 Jan 16. doi: 10.1007/s10519-021-10095-3. Online ahead of print.

ABSTRACT

Multivariate twin and family studies are one of the most important tools to assess diseases inheritance as well as to study their genetic and environment interrelationship. The multivariate analysis of twin and family data is in general based on structural equation modelling or linear mixed models that essentially decomposes sources of covariation as originally suggested by Fisher. In this paper, we propose a flexible and unified statistical modelling framework for analysing multivariate Gaussian and non-Gaussian twin and family data. The non-normality is taken into account by actually modelling the mean and variance relationship, while the covariance structure is modelled by means of a linear covariance model including the option to model the dispersion components as functions of known covariates in a regression model fashion. The marginal specification of our models allows us to extend classic models and biometric indices such as the bivariate heritability, genetic, environmental and phenotypic correlations to non-Gaussian data. We illustrate the proposed models through simulation studies and six data analyses and provide computational implementation in R through the package mglm4twin.

PMID:35034249 | DOI:10.1007/s10519-021-10095-3

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Nevin Manimala Statistics

Predictive performance and clinical utility of HCC risk scores in chronic hepatitis C: a comparative study

Hepatol Int. 2022 Jan 16. doi: 10.1007/s12072-021-10284-6. Online ahead of print.

ABSTRACT

BACKGROUND AND AIM: Many HCC risk prediction scores were developed to guide HCC risk stratification and identify CHC patients who either need intensified surveillance or may not require screening. There is a need to compare different scores and their predictive performance in clinical practice. We aim to compare the newest HCC risk scores evaluating their discriminative ability, and clinical utility in a large cohort of CHC patients.

PATIENTS AND METHODS: The performance of the scores was evaluated in 3075 CHC patients who achieved SVR following DAAs using Log rank, Harrell’s c statistic, also tested for HCC-risk stratification and negative predictive values.

RESULTS: HCC developed in 212 patients within 5 years follow-up. Twelve HCC risk scores were identified and displayed significant Log rank (p ≤ 0.05) except Alonso-Lopez TE-HCC, and Chun scores (p = 0.374, p = 0.053, respectively). Analysis of the remaining ten scores revealed that ADRES, GES pre-post treatment, GES algorithm and Watanabe (post-treatment) scores including dynamics of AFP, were clinically applicable and demonstrated good statistical performance; Log rank analysis < 0.001, Harrell’s C statistic (0.66-0.83) and high negative predictive values (94.38-97.65%). In these three scores, the 5 years cumulative IR in low risk groups be very low (0.54-1.6), so screening could be avoided safely in these patients.

CONCLUSION: ADRES, GES (pre- and post-treatment), GES algorithm and Watanabe (post-treatment) scores seem to offer acceptable HCC-risk predictability and clinical utility in CHC patients. The dynamics of AFP as a component of these scores may explain their high performance when compared to other scores.

PMID:35034266 | DOI:10.1007/s12072-021-10284-6

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Nevin Manimala Statistics

Region-Dependent Viscoelastic Properties of Human Brain Tissue Under Large Deformations

Ann Biomed Eng. 2022 Jan 15. doi: 10.1007/s10439-022-02910-7. Online ahead of print.

ABSTRACT

This study characterizes the mechanical properties of human brain tissue resected during the course of surgery under multistep indentation loading up to 30% strain. The experimental characterization using fresh, post-operative, human brain tissue is highly advantageous since postmortem times can affect its biomechanical behavior. Although the quasilinear theory of viscoelasticity (QLV) approach has been widely used to model brain tissue mechanical properties, our analysis concluded that the linear viscoelastic approach provided a better fit to the experimental data overall. The only statistically significant regional difference in observed stiffness was between the cortex gray and dentate gyrus. There were no statistically significant age or sex dependent differences, although the data suggested that the cortex white matter in males was stiffer than that in females. Our results can help improve the accuracy of finite element models of brain tissue deformation to predict its response to traumatic brain injury.

PMID:35034227 | DOI:10.1007/s10439-022-02910-7

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Nevin Manimala Statistics

Longitudinal associations between problematic Internet use, self-esteem, and depressive symptoms among Chinese adolescents

Eur Child Adolesc Psychiatry. 2022 Jan 15. doi: 10.1007/s00787-022-01944-5. Online ahead of print.

ABSTRACT

Problematic Internet use (PIU) has a negative impact on self-esteem among adolescents, thereby making them be vulnerable to developing depressive symptoms. However, there is a lack of longitudinal studies focusing on the process. This study aimed to explore the longitudinal associations between PIU, self-esteem, and depressive symptoms. A total of 1,736 adolescents completed this longitudinal study. The baseline survey was conducted in 2019, and the follow-up surveys were performed at 1-year and 2-year later. PIU, self-esteem, and depressive symptoms were measured. A cascade model was used to examine the longitudinal associations between PIU, self-esteem, and depressive symptoms. The mean age of participants was 13.6 (1.5) years at baseline. The final results observed significant within-time associations between PIU, self-esteem, and depressive symptoms at each time point. PIU and low level of self-esteem could predict subsequent depressive symptoms among adolescents, and depressive symptoms were also associated with subsequent PIU and self-esteem. Both PIU and self-esteem show bidirectional predictions with depressive symptoms among Chinese adolescents. Schools and parents should give more attention to adolescents prone to developing depressive symptoms and more social support to reduce their negative emotions. Health-related professionals should incorporate practical knowledge and skills into the education of adolescents to help them better control Internet use, attenuating the risk of future depressive symptoms.

PMID:35034212 | DOI:10.1007/s00787-022-01944-5

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Nevin Manimala Statistics

A calibrated Bayesian method for the stratified proportional hazards model with missing covariates

Lifetime Data Anal. 2022 Jan 16. doi: 10.1007/s10985-021-09542-4. Online ahead of print.

ABSTRACT

Missing covariates are commonly encountered when evaluating covariate effects on survival outcomes. Excluding missing data from the analysis may lead to biased parameter estimation and a misleading conclusion. The inverse probability weighting method is widely used to handle missing covariates. However, obtaining asymptotic variance in frequentist inference is complicated because it involves estimating parameters for propensity scores. In this paper, we propose a new approach based on an approximate Bayesian method without using Taylor expansion to handle missing covariates for survival data. We consider a stratified proportional hazards model so that it can be used for the non-proportional hazards structure. Two cases for missing pattern are studied: a single missing pattern and multiple missing patterns. The proposed estimators are shown to be consistent and asymptotically normal, which matches the frequentist asymptotic properties. Simulation studies show that our proposed estimators are asymptotically unbiased and the credible region obtained from posterior distribution is close to the frequentist confidence interval. The algorithm is straightforward and computationally efficient. We apply the proposed method to a stem cell transplantation data set.

PMID:35034213 | DOI:10.1007/s10985-021-09542-4

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Nevin Manimala Statistics

Booster administration can make a difference in the antibody response to intradermal foot-and-mouth disease vaccination in cattle

Arch Virol. 2022 Jan 16. doi: 10.1007/s00705-021-05273-x. Online ahead of print.

ABSTRACT

Foot-and-mouth disease (FMD) is a highly contagious and economically important viral disease of cloven-hoofed animals. Routine vaccination is one of the preferred methods of protection against this disease in endemic countries. For protective immunity against FMD, repeated immunizations with frequent administration are required. Intradermal immunization has many advantages over intramuscular administration of vaccines. In this study, a commercial tetravalent FMD vaccine adjuvanted with Montanide ISA 206 was administered to cattle via the intramuscular (2 mL [n = 10] and 0.5 mL [n = 9]) and intradermal (0.5 mL [n = 11]) routes. Booster doses were administered 28 days later using the same vaccine and routes. Serum samples were collected on days 0, 7, 14, and 28 post-vaccination (pv) and at 30 and 60 days post-booster. Homologous and heterologous virus neutralization tests and liquid-phase blocking and isotype ELISAs were used to measure the antibody response. The results showed that intradermal administration of quarter doses of the vaccine provides an equal or better virus neutralization antibody response than intramuscular administration of the same dose of vaccine after booster administration in cattle. This means that four times more cattle can be immunized with the same amount of vaccine using the intradermal route without compromising immunity.

PMID:35034176 | DOI:10.1007/s00705-021-05273-x

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Nevin Manimala Statistics

Aortic haemodynamics: the effects of habitual endurance exercise, age and muscle sympathetic vasomotor outflow in healthy men

Eur J Appl Physiol. 2022 Jan 16. doi: 10.1007/s00421-021-04883-2. Online ahead of print.

ABSTRACT

PURPOSE: We determined the effect of habitual endurance exercise and age on aortic pulse wave velocity (aPWV), augmentation pressure (AP) and systolic blood pressure (aSBP), with statistical adjustments of aPWV and AP for heart rate and aortic mean arterial pressure, when appropriate. Furthermore, we assessed whether muscle sympathetic nerve activity (MSNA) correlates with AP in young and middle-aged men.

METHODS: Aortic PWV, AP, aortic blood pressure (applanation tonometry; SphygmoCor) and MSNA (peroneal microneurography) were recorded in 46 normotensive men who were either young or middle-aged and endurance-trained runners or recreationally active nonrunners (10 nonrunners and 13 runners within each age-group). Between-group differences and relationships between variables were assessed via ANOVA/ANCOVA and Pearson product-moment correlation coefficients, respectively.

RESULTS: Adjusted aPWV and adjusted AP were similar between runners and nonrunners in both age groups (all, P > 0.05), but higher with age (all, P < 0.001), with a greater effect size for the age-related difference in AP in runners (Hedges’ g, 3.6 vs 2.6). aSBP was lower in young (P = 0.009; g = 2.6), but not middle-aged (P = 0.341; g = 1.1), runners compared to nonrunners. MSNA burst frequency did not correlate with AP in either age group (young: r = 0.00, P = 0.994; middle-aged: r = – 0.11, P = 0.604).

CONCLUSION: There is an age-dependent effect of habitual exercise on aortic haemodynamics, with lower aSBP in young runners compared to nonrunners only. Statistical adjustment of aPWV and AP markedly influenced the outcomes of this study, highlighting the importance of performing these analyses. Further, peripheral sympathetic vasomotor outflow and AP were not correlated in young or middle-aged normotensive men.

PMID:35034204 | DOI:10.1007/s00421-021-04883-2

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Nevin Manimala Statistics

Effect of cognitive task complexity on dual task postural stability: a systematic review and meta-analysis

Exp Brain Res. 2022 Jan 16. doi: 10.1007/s00221-021-06299-y. Online ahead of print.

ABSTRACT

The dual task experimental paradigm is used to probe the attentional requirements of postural control. However, findings of dual task postural studies have been inconsistent with many studies even reporting improvement in postural stability during dual tasking and thus raising questions about cognitive involvement in postural control. A U-shaped non-linear relationship has been hypothesized between cognitive task complexity and dual task postural stability suggesting that the inconsistent results might have arisen from the use of cognitive tasks of varying complexities. To systematically review experimental studies that compared the effect of simple and complex cognitive tasks on postural stability during dual tasking, we searched seven electronic databases for relevant studies published between 1980 to September 2020. 33 studies involving a total of 1068 participants met the review’s inclusion criteria, 17 of which were included in meta-analysis (healthy young adults: 15 studies, 281 participants; Stroke patients: 2 studies, 52 participants). Narrative synthesis of the findings in studies involving healthy old adults was carried out. Our result suggests that in healthy population, cognitive task complexity may not determine whether postural stability increases or decreases during dual tasking (effect of cognitive task complexity was not statistically significant; P > 0.1), and thus the U-shaped non-linear hypothesis is not supported. Rather, differential effect of dual tasking on postural stability was observed mainly based on the age of the participants and postural task challenge, implying that the involvement of cognitive resources or higher cortical functions in the control of postural stability may largely depends on these two factors.

PMID:35034175 | DOI:10.1007/s00221-021-06299-y

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Nevin Manimala Statistics

Bladder cancer in patients with neurogenic bladder disorder: a comparative study of different etiologies

World J Urol. 2022 Jan 15. doi: 10.1007/s00345-021-03922-z. Online ahead of print.

ABSTRACT

PURPOSE: The objective of this study was to conduct a comparative study of different etiologies of neurogenic bladder disorders (NBDs) in patients with bladder cancer (BC) regarding patient- and tumor-related parameters and their oncological outcome.

METHODS: Out of 98 patients with bladder tumors and neurogenic disease, 23 patients with BC and NBDs from Jan 1, 2010, to Dec 31, 2020, were included. The different etiologies of NBDs were merged in three groups based on the level of the nervous system (NS)-lesion: (i) central (n = 6), (ii) spinal cord (n = 10), and (iii) peripheral lesions (n = 7).

RESULTS: Patients with lesions at the spinal cord level were younger at the time of BC diagnosis compared to patients with central or peripheral NS lesions (54 vs. 68 vs. 78 years, p = 0.0219). However, the latency to malignant transformation was more than twice as long (33 vs. 15 years, p = 0.0108). Most tumors were muscle-invasive or locally advanced BCs (62%) and presented lymph node metastases (55%), resulting in a poor mean overall survival of 30.9 ± 3.6 months. No significant differences regarding histopathology, tumor stage, and oncological outcome could be observed between the groups.

CONCLUSION: Patients with NBDs have a poor prognosis regardless of their etiology or the level of NS lesion. Patients with spinal cord lesions, including congenital NBDs, appear to develop BC at a young age, but compared to other etiologies latency from NBD to BC is longer.

PMID:35034168 | DOI:10.1007/s00345-021-03922-z

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Nevin Manimala Statistics

Factors associated with poor maternal health care services utilization in Eswatini: A secondary analysis of a nationally representative household survey

Midwifery. 2022 Jan 7;106:103250. doi: 10.1016/j.midw.2022.103250. Online ahead of print.

ABSTRACT

BACKGROUND: This study investigated the prevalence and factors associated with poor maternal health care services utilization (MHCSU) i.e., having < 4 antenatal care (ANC) visits, not delivering at a health facility, and not receiving institutional postnatal care (PNC).

METHODS: We conducted a secondary analysis of data from the 2014 Eswatini Multiple Cluster Indicator Survey, a cross-sectional, nationally representative household survey. Participants were childbearing women (15-49 years) who had a live birth in the past two years preceding the survey. Multivariable logistic regression analyses were performed for each outcome variable.

RESULTS: The prevalence of poor MHCSU was 22.1% (202/903) for ANC, 10.4% (102/899) for institutional delivery or intrapartum care (IPC), and 26.9% (123/598) for PNC. Being younger, having a low education level, being never married, having no access to mass media, being a household head of low education, coming from a household of poor/middle wealth index, being a primipara, having an unintended pregnancy, and having a longer length of stay in the postpartum ward were significantly associated with poor MHCSU.

CONCLUSION: Midwives should pay special attention to women who present with the factors associated with poor MHCSU identified in this study, as early as the first booking for ANC to intervene early.

PMID:35032933 | DOI:10.1016/j.midw.2022.103250