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Nevin Manimala Statistics

Nephron-sparing management of upper tract urothelial carcinoma

Investig Clin Urol. 2021 Jul;62(4):389-398. doi: 10.4111/icu.20210113.

ABSTRACT

Urothelial carcinoma of the upper urinary tract is uncommon and presents unique challenges for diagnosis and management. Nephroureterectomy has been the preferred management option, but it is associated with significant morbidity. Nephron-sparing treatments are a valuable alternative and provide similar efficacy in select cases. A PubMed literature review was performed in English language publications using the following search terms: urothelial carcinoma, upper tract, nephron-sparing, intraluminal and systemic therapy. Contemporary papers published within the last 10 years were primarily included. Where encountered, systematic reviews and meta-analyses were given priority, as were randomized controlled trials for newer treatments. Core guidelines were referenced and citations reviewed for inclusion. A summary of epidemiological data, clinical diagnosis, staging, and treatments focusing on nephron-sparing approaches to upper tract urothelial carcinoma (UTUC) are outlined. Nephron-sparing management strategies are viable options to consider in patients with favorable features of UTUC. Adjunctive therapies are being investigated but the data remains mixed. Protocol variability and dosage differences limit statistical interpretation. New mechanisms to improve treatment dwell times in the upper tracts are being designed with promising preliminary results. Studies investigating systemic therapies are ongoing but implications for nephron-sparing management are uncertain. Nephron-sparing management is an acceptable treatment modality best suited for favorable disease. More work is needed to determine if intraluminal and/or systemic therapies can further optimize treatment outcomes beyond resection alone.

PMID:34190434 | DOI:10.4111/icu.20210113

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Nevin Manimala Statistics

Frequency of root fenestration in a Greek subpopulation: A cone beam computed tomography clinical study

Aust Endod J. 2021 Jun 30. doi: 10.1111/aej.12523. Online ahead of print.

ABSTRACT

This cone beam computed tomography (CBCT) study aimed to assess the root fenestration (RF) frequency in healthy, intact teeth and analyse their features in a Greek subpopulation. 432 CBCT scans were examined. 5486 teeth were evaluated for RF prevalence. RF prevalence and distribution were recorded for each jaw, tooth group, as well as patient age and sex. RF symmetry, distribution to the affected root surface and the effects of age and sex were evaluated. The prevalence of RF ranged from 0.57% (central incisors) to 7.18% (first premolars) and from 0.48% (second premolars) to 10.79% (lateral incisors) for the maxilla and the mandible, respectively. No symmetrical occurrence of RF was detected. Most RF patients presented one or two defects in both jaws. Types I and IV were the most prevalent in the maxilla, while Types III, II and V were the most prevalent in the mandible. No statistical difference was detected between different sexes and age groups (P > 0.05).

PMID:34190384 | DOI:10.1111/aej.12523

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Nevin Manimala Statistics

Feasibility of Oral Tranexamic acid (TA) for Vitiligo Patients with Melasma

Dermatol Ther. 2021 Jun 30:e15047. doi: 10.1111/dth.15047. Online ahead of print.

ABSTRACT

BACKGROUND: Melasma and vitiligo are both common pigmentary disorders, and the treatment is challenging. Oral tranexamic acid (TA) is effective for refractory melasma; however, the feasibility of TA in vitiligo patients with melasma was not studied.

OBJECTIVES: To evaluate the treatment outcomes and adverse effects of oral TA in vitiligo patients with melasma.

METHODS: We conducted a retrospective analysis of vitiligo patients who received oral TA for melasma in a tertiary dermatologic center from January 2017 to August 2020.

RESULTS: We enrolled 32 patients with concomitant vitiligo and melasma on the face. The mean duration of the improvement of melasma that patients reported is around 1.64 months of treatment. The first sign of repigmentation of the vitiligo lesions occurred at one month of treatment. 84.38% of the patients achieved a mild to good degree of improvement of melasma (0-75% improvement), whereas 81.25% of the patients achieved a moderate to excellent degree of improvement of vitiligo (25-100% improvement) via physician global assessments. No significant adverse event was noted. No patients experience vitiligo disease deterioration during TA treatment.

CONCLUSION: Oral TA may be a feasible option for melasma in vitiligo patients.

PMID:34190390 | DOI:10.1111/dth.15047

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Nevin Manimala Statistics

Knowledge and practice of diabetic foot care and the prevalence of diabetic foot ulcers among diabetic patients of selected hospitals in the Volta Region, Ghana

Int Wound J. 2021 Jun 30. doi: 10.1111/iwj.13656. Online ahead of print.

ABSTRACT

Diabetic foot ulcers (DFUs) are a common but serious complication of diabetes mellitus (DM). The factors distressing the worth of diabetic foot care (DFC) are knowledge and practice. Foot ulcers are the main cause of amputation and death in people suffering from DM. This study assessed the knowledge and practice of DFC and the prevalence of DFUs and its associated factors among diabetic patients of selected hospitals in the Volta Region, Ghana. A multihospital-based cross-sectional study was conducted among 473 patients with DM who were recruited using the systematic sampling method. Data were collected using a validated, pretested, and structured questionnaire, while medical variables were obtained from patient folders and analysed using SPSS version 23. All statistically significant parameters in bivariate analysis were incorporated in the multivariate logistic regression analysis. The results showed that 63% of diabetic patients had good knowledge of DFC, while 49% competently practiced it. A negative correlation was found between knowledge and practice levels of DFC (r = -0.15, P = <.01). The prevalence of DFUs was 8.7% among the studied diabetic patients. Male diabetic patients were 3.4 times more likely to develop DFUs than female diabetic patients (crude odd ratio [cOR] = 3.35; 95% confidence interval [CI] = 1.75-6.43; P = <.001). Type 1 diabetic patients were five times more likely to develop DFUs than those who had type 2 diabetes (cOR = 5.00; 95% CI = 2.50-10.00; P = <.001). Diabetic patients who had a family history of diabetes were 4.7 times more likely to develop DFUs than those without family history (adjusted odd ratio [aOR] = 4.66; 95% CI = 1.55-13.89; P = .006). Those who had diabetes for 5 to 10 years were 3.3 times more likely to develop DFUs than those who had diabetes for less than 5 years (aOR = 3.28; 95% CI = 1.40-7.67; P = .006). Diabetic patients who had comorbidity were 3.4 times more likely to develop DFUs than those without comorbidity (cOR = 3.35; 95% CI = 1.74-6.45; P = <.001). The study found that there was good knowledge but poor practices of DFC among patients. Health care providers are expected to better educate patients and emphasise self-care practices to patients. Health care providers should also give more attention to patients with associated risk factors to avoid further complications and reduce the occurrence of DFUs.

PMID:34190402 | DOI:10.1111/iwj.13656

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Nevin Manimala Statistics

Integration of survival data from multiple studies

Biometrics. 2021 Jun 30. doi: 10.1111/biom.13517. Online ahead of print.

ABSTRACT

We introduce a statistical procedure that integrates datasets from multiple biomedical studies to predict patients’ survival, based on individual clinical and genomic profiles. The proposed procedure accounts for potential differences in the relation between predictors and outcomes across studies, due to distinct patient populations, treatments and technologies to measure outcomes and biomarkers. These differences are modeled explicitly with study-specific parameters. We use hierarchical regularization to shrink the study-specific parameters towards each other and to borrow information across studies. The estimation of the study-specific parameters utilizes a similarity matrix, which summarizes differences and similarities of the relations between covariates and outcomes across studies. We illustrate the method in a simulation study and using a collection of gene expression datasets in ovarian cancer. We show that the proposed model increases the accuracy of survival predictions compared to alternative meta-analytic methods.

PMID:34190337 | DOI:10.1111/biom.13517

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Nevin Manimala Statistics

Pitfalls in brain age analyses

Hum Brain Mapp. 2021 Jun 30. doi: 10.1002/hbm.25533. Online ahead of print.

ABSTRACT

Over the past decade, there has been an abundance of research on the difference between age and age predicted using brain features, which is commonly referred to as the “brain age gap.” Researchers have identified that the brain age gap, as a linear transformation of an out-of-sample residual, is dependent on age. As such, any group differences on the brain age gap could simply be due to group differences on age. To mitigate the brain age gap’s dependence on age, it has been proposed that age be regressed out of the brain age gap. If this modified brain age gap is treated as a corrected deviation from age, model accuracy statistics such as R2 will be artificially inflated to the extent that it is highly improbable that an R2 value below .85 will be obtained no matter the true model accuracy. Given the limitations of proposed brain age analyses, further theoretical work is warranted to determine the best way to quantify deviation from normality.

PMID:34190372 | DOI:10.1002/hbm.25533

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Nevin Manimala Statistics

HIV infection and risk of COVID-19 mortality: A meta-analysis

Medicine (Baltimore). 2021 Jul 2;100(26):e26573. doi: 10.1097/MD.0000000000026573.

ABSTRACT

BACKGROUND: This meta-analysis aimed to estimate the association of human immunodeficiency virus (HIV) infection and risk of coronavirus disease 2019 (COVID-19) mortality.

METHODS: We systematically retrieved articles published on HIV infection and risk of COVID-19 mortality through PubMed, EMBase, China National Knowledge Infrastructure, WanFang, and Chongqing VIP databases using a predefined search strategy from December 1, 2019 to January 31, 2021. Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. Cochran Q test and I2 statistics were quantified to measure heterogeneity. Odds ratio (OR) and 95% confidence intervals (CI) were computed and displayed in the form of forest plots. Subgroup analysis was performed to explore the source of heterogeneity. Funnel plot, Begg test, and Egger test were used to assess potential publication bias. Stata software version 11.0 was used to analyze all the statistical data.

RESULTS: We included 10 studies with 18,122,370 COVID-19 patients, of whom 41,113 were with HIV infection and 18,081,257 were without HIV infection. The pooled overall results suggested that people living with HIV infection had a higher risk of mortality from COVID-19 than those without HIV infection (OR = 1.252, 95% CI 1.027-1.524). Subgroup analysis showed that people living with HIV infection had a higher risk of COVID-19 mortality than those without HIV infection in the United States (OR = 1.520, 95% CI 1.252-1.845) and in South Africa (OR = 1.122, 95% CI 1.032-1.220); however, no significant association was found in the United Kingdom (OR = 0.878, 95% CI 0.657-1.174).

CONCLUSION: Patients with HIV infection should be the emphasis population to prevent the risk of mortality during the clinical treatment of COVID-19 patients.

PMID:34190201 | DOI:10.1097/MD.0000000000026573

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Nevin Manimala Statistics

Synthesizing Indirect Effects in Mediation Models With Meta-Analytic Methods

Alcohol Alcohol. 2021 Jun 30:agab044. doi: 10.1093/alcalc/agab044. Online ahead of print.

ABSTRACT

AIMS: A mediator is a variable that explains the underlying mechanism between an independent variable and a dependent variable. The indirect effect indicates the effect from the predictor to the outcome variable via the mediator. In contrast, the direct effect represents the predictor’s effort on the outcome variable after controlling for the mediator.

METHODS: A single study rarely provides enough evidence to answer research questions in a particular domain. Replications are generally recommended as the gold standard to conduct scientific research. When a sufficient number of studies have been conducted addressing similar research questions, a meta-analysis can be used to synthesize those studies’ findings.

RESULTS: The main objective of this paper is to introduce two frameworks to integrating studies using mediation analysis. The first framework involves calculating standardized indirect effects and direct effects and conducting a multivariate meta-analysis on those effect sizes. The second one uses meta-analytic structural equation modeling to synthesize correlation matrices and fit mediation models on the average correlation matrix. We illustrate these procedures on a real dataset using the R statistical platform.

CONCLUSION: This paper closes with some further directions for future studies.

PMID:34190317 | DOI:10.1093/alcalc/agab044

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Nevin Manimala Statistics

Varying-coefficient regression analysis for pooled biomonitoring

Biometrics. 2021 Jun 30. doi: 10.1111/biom.13516. Online ahead of print.

ABSTRACT

Human biomonitoring involves measuring the accumulation of contaminants in biological specimens (such as blood or urine) to assess individuals exposure to environmental contamination. Due to the expensive cost of a single assay, the method of pooling has become increasingly common in environmental studies. The implementation of pooling starts by physically mixing specimens into pools, and then measures pooled specimens for the concentration of contaminants. An important task is to reconstruct individual-level statistical characteristics based on pooled measurements. In this article, we propose to use the varying-coefficient regression model for individual-level biomonitoring and provide methods to estimate the varying-coefficients based on different types of pooled data. Asymptotic properties of the estimators are presented. We illustrate our methodology via simulation and with application to pooled biomonitoring of a brominated flame retardant provided by the National Health and Nutrition Examination Survey (NHANES). This article is protected by copyright. All rights reserved.

PMID:34190334 | DOI:10.1111/biom.13516

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Nevin Manimala Statistics

Association study of the serum 25(OH)D concentration and myopia in Chinese children

Medicine (Baltimore). 2021 Jul 2;100(26):e26570. doi: 10.1097/MD.0000000000026570.

ABSTRACT

To analyze the serum 25 hydroxyvitamin D (25[OH]D) concentration in Chinese children with myopia and explore its correlation with myopia.From July to September in 2019, myopic children were collected from the Myopia Influencing Factors Survey Project. The basic information and vision related behaviors of the subjects were collected by questionnaire. The diopter of the children without dilated pupils was measured by the computerized refractometer. Meanwhile, 5 ml fasting venous blood samples were collected for the determination of serum 25(OH)D concentration.A total of 186 children were included in this study, including 90 males and 96 females, with an average age of 8 ± 3.26 years. The detection rate of serum 25(OH)D deficiency in myopic children was 65.59% (122/186). There was statistical significance in the detection rate of serum 25(OH)D deficiency in children with different myopic degrees (χ2 = 6.635, P = .010). The average serum 25(OH)D concentration in myopic children was 14.86 (10.67-18.96) ng/ml, and the difference of serum 25(OH)D concentration in children with different myopia degrees was statistically significant (Z = 20.23, P < .001). Logistic regression analysis showed that after controlling for gender, parental myopia, after-school class, and outdoor activities, the prevalence of developing moderate and high myopia was 2.051 times (95% confidence interval: 1.272-3.724) higher in the serum 25(OH)D deficiency group than in the serum 25(OH)D sufficiency group. There is a positive correlation between serum 25(OH)D concentration and the equivalent spherical degree of myopic children.The study found that serum 25(OH)D concentration is closely related to the prevalence of myopia in Chinese children. The results further support the conclusion that children with a higher level of serum 25(OH)D have a lower prevalence of moderate to high myopia. The results of this study provide a basis for further research into the relationship between vitamin D and visual development in children and its mechanisms.

PMID:34190200 | DOI:10.1097/MD.0000000000026570