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Nevin Manimala Statistics

Bayesian nonparametric analysis of restricted mean survival time

Biometrics. 2022 Jan 16. doi: 10.1111/biom.13622. Online ahead of print.

ABSTRACT

The restricted mean survival time (RMST) evaluates the expectation of survival time truncated by a prespecified time point, because the mean survival time in presence of censoring is typically not estimable. The frequentist inference procedure for RMST has been widely advocated for comparison of two survival curves, while research from the Bayesian perspective is rather limited. For the RMST of both right- and interval-censored data, we propose Bayesian nonparametric estimation and inference procedures. By assigning a mixture of Dirichlet processes (MDP) prior to the distribution function, we can estimate the posterior distribution of RMST. We also explore another Bayesian nonparametric approach using the Dirichlet process mixture model and make comparisons with the frequentist nonparametric method. Simulation studies demonstrate that the Bayesian nonparametric RMST under diffuse MDP priors leads to robust estimation and under informative priors it can incorporate prior knowledge into the nonparametric estimator. Analysis of real trial examples demonstrates the flexibility and interpretability of the Bayesian nonparametric RMST for both right- and interval-censored data. This article is protected by copyright. All rights reserved.

PMID:35034347 | DOI:10.1111/biom.13622

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Nevin Manimala Statistics

A clinical approach strategy for the diagnosis, treatment and evaluation of external cervical resorption

Int Endod J. 2022 Jan 16. doi: 10.1111/iej.13680. Online ahead of print.

ABSTRACT

AIM: To propose a clinical approach strategy on the diagnosis, treatment, and evaluation of external cervical tooth resorption (ECR) cases. To investigate and discuss the outcome of this approach.

METHODOLOGY: A clinical approach strategy on ECR was developed based on a retrospective observation study of 542 teeth. 47 teeth were excluded due to lack of clinical/radiographical information, and 182 were immediately extracted. This approach had three steps: diagnosis, treatment planning, and evaluation. During diagnosis, the medical, dental history and clinical/radiographical characteristics were evaluated. Depending on the resorption extent, ECR cases were categorized into four classes according to Heithersay’s classification. During treatment planning, a treatment decision flowchart was prepared based on four main decisive criteria: probing feasibility, pain, location and extent of resorption (class), and existence of bonelike tissue. Three treatment options were applied: a) extraction, b) monitoring, or c) conservative treatment by external, internal, or combination of internal-external treatments. During evaluation, assessment of ECR progression, tooth survival and other factors like esthetics and periodontal attachment were performed. Descriptive statistical analysis of the outcome for up to ten years (for the overall clinical approach and for each individual treatment decision), was carried out with OriginLabs OriginPro 9 and Microsoft Excel 365.

RESULTS: A three-step strategy was developed on how to deal with ECR cases. Indicative examples of each treatment decision were presented and discussed. The overall survival rate of this strategy was 84.6% (3 years), 70.3% (5 years), 42.7% (8 years) and 28.6% (10 years). Higher survival rate was observed for external treatment decision than for internal. The success of each treatment decision depended on the extent of the resorption (class). The success of a treatment decision should be based on the long-term outcome, as a different evolution can be observed with time.

CONCLUSIONS: A clinical approach strategy was introduced on ECR pathosis. This strategy was not solely based on ECR class, as other important decisive criteria were considered. This step-wise approach, has a 70.3% survival rate with a mean of 5 years. This work will hopefully provide an incentive for a broader collaboration, to potentially establish a universally accepted ECR treatment strategy.

PMID:35034370 | DOI:10.1111/iej.13680

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Nevin Manimala Statistics

Coronary revascularisation outcome questionnaire: validation study of the Serbian version

Qual Life Res. 2022 Jan 16. doi: 10.1007/s11136-021-03064-0. Online ahead of print.

ABSTRACT

PURPOSE: To translate, culturally adapt and validate the Coronary Revascularisation Outcome Questionnaire (CROQ), a disease-specific tool for measuring health-related quality of life (HRQoL) in patients with ischaemic heart disease (IHD), into Serbian language (CROQ-S).

METHODS: Validation study was performed at the Clinic for Cardiac Surgery and Clinic for Cardiology, University Clinical Centre of Serbia. We included a convenience sample of 600 patients with IHD divided into four groups. Acceptability, reliability and validity of the CROQ-S were assessed.

RESULTS: CROQ-S was acceptable to patients as demonstrated by less than 1% of missing data for each single item. Cronbach’s Alpha was higher than the criterion of 0.70 for all scales in each version except the Cognitive Functioning scale which only met this criterion in the CABG pre-revascularisation version. Mean values of item-total correlations were greater than 0.30 for all scales except the Cognitive Functioning scale in both the pre-revascularisation groups. Compared to the original version, exploratory factor analysis in our study showed more factors; however, the majority of items had a factor loading greater than 0.3 on the right scale. Correlations of CROQ-S scales with the 36-Item Short Form Health Survey and Seattle Angina Questionnaire showed the expected pattern whereby scales measuring similar constructs were most highly correlated.

CONCLUSION: CROQ-S is an acceptable, reliable and valid disease-specific instrument for measuring HRQoL in this sample of Serbian speaking patients with IHD both before and after coronary revascularisation. However, the Cognitive Functioning scale did not meet all the psychometric criteria and further validation of its responsiveness is required.

PMID:35034321 | DOI:10.1007/s11136-021-03064-0

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Nevin Manimala Statistics

Prevalence and Cost of Care for Parkinson’s Disease in Luxembourg: An Analysis of National Healthcare Insurance Data

Pharmacoecon Open. 2022 Jan 16. doi: 10.1007/s41669-021-00321-3. Online ahead of print.

ABSTRACT

BACKGROUND: Parkinson’s disease (PD) is the second most common neurodegenerative disorder, with an increasing prevalence worldwide. Estimates of the economic burden associated with PD vary widely across existing studies due to differences in setting and study design. The prevalence and cost of care for PD in Luxembourg are currently unknown.

OBJECTIVE: The aims of this study were to estimate (1) the prevalence of PD in Luxembourg and (2) the cost of care for PD to the national healthcare insurance based on routinely collected healthcare data.

METHODS: This analysis was based on individual patient-level data collected by the national healthcare insurance in Luxembourg during 2007-2017, which covers over 95% of the resident population. People with PD were identified based on drug reimbursement profiles. Cost of care was estimated according to a comparative analysis of the healthcare resources consumed by people with PD compared with an age- and sex-matched control group.

RESULTS: We determined a PD prevalence of 928 per 100,000 individuals aged 50 years and older in 2016, higher in men (1032 per 100,000) than in women (831 per 100,000). The total mean cost of care for PD was estimated at €22,673 per patient per year in 2016, with the highest costs being associated with long-term care (69%).

CONCLUSION: This was the first attempt to estimate the prevalence and cost of care of PD in Luxembourg. The work demonstrated the usefulness of routinely collected data in Luxembourg for such analyses. Our study confirms the significant burden of PD to the healthcare system, especially on long-term care.

PMID:35034346 | DOI:10.1007/s41669-021-00321-3

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Nevin Manimala Statistics

Impact on mental health of the COVID-19 pandemic in a radiation oncology department

Radiol Med. 2022 Jan 16. doi: 10.1007/s11547-021-01440-x. Online ahead of print.

ABSTRACT

AIM: To evaluate the emotional state and organizational well-being of healthcare workers in radiation oncology departments, during the COVID pandemic.

METHODS: A survey was carried out with three questionnaires: Impact of Event Scale-Revised (IES-R); Italian ANAC questionnaire; and Maslach Burnout Inventory (MBI). Comparisons between groups were done by Student’s t test.

RESULTS: Seventy-eight questionnaires for 26 workers were analyzed. Thirty-three percent of the sample obtained an IES-R high score, such as post-traumatic syndrome. In terms of organizational well-being, younger age and lower working seniority were statistically significant for higher score of ANAC items (p < 0.5). Regarding MBI, 0, 27 and 50% high scores of emotional exhaustion, depersonalization and personal accomplishment were reported, respectively. Low working seniority and male sex were correlated with high score of personal accomplishment (p:0.05; p:0.03).

CONCLUSION: Intervention to promote mental health well-being should be implemented in radiation oncology department.

PMID:35034319 | DOI:10.1007/s11547-021-01440-x

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Nevin Manimala Statistics

A Dalbavancin Lock Solution Can Reduce Enterococcal Biofilms After Freezing

Infect Dis Ther. 2022 Jan 16. doi: 10.1007/s40121-021-00579-4. Online ahead of print.

ABSTRACT

INTRODUCTION: We previously demonstrated the efficacy of a frozen dalbavancin-heparin (DH) lock solution against biofilms of staphylococci. However, as enterococci also commonly cause catheter-related bloodstream infections (C-RBSI), we assessed the bioactivity of frozen dalbavancin (D) and DH against enterococci.

METHODS: Over 6 months, we compared the bioactivity of a solution of DH (1 mg/ml) with that of D in terms of cfu counts and metabolic activity against biofilms of Enterococcus faecalis and Enterococcus faecium (four strains each). For each solution, we individually compared results obtained at each time point (months 3 and 6) with baseline (month 0). We also compared the median DH value of each variable at baseline and at months 3 and 6 of freezing with the values obtained for D alone. We used both statistical and clinical criteria when results were within 25% of the reference value.

RESULTS: At the end of the experiment (month 6), neither a statistically nor a clinically significant reduction in the bioactivity of D solution was observed in terms of cfu count and metabolic activity against enterococcal biofilms. Regarding the DH solution, we found both statistical and clinical significance in the median percentage reduction in metabolic activity between months 0 and 6 in E. faecalis strains (51.8% vs. 77.8%, P = 0.007). Moreover, after freezing, the DH solution lost significant bioactivity compared with the D solution, especially in E. faecalis.

CONCLUSION: A dalbavancin lock solution can be frozen for up to 6 months with no negative effect on its bioactivity against enterococcal biofilms. However, when combined with heparin, its efficacy was reduced. Therefore, we recommend that if lock therapy with frozen dalbavancin is used in the management of enterococcal C-RBSI, heparin should be added simultaneously at the time of catheter lock.

PMID:35034289 | DOI:10.1007/s40121-021-00579-4

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Nevin Manimala Statistics

Evaluation of traffic noise pollution using geographic information system and descriptive statistical method: a case study in Mashhad, Iran

Environ Sci Pollut Res Int. 2022 Jan 15. doi: 10.1007/s11356-022-18532-4. Online ahead of print.

ABSTRACT

Environmental consequences and the epidemiologic results of noise pollution have chronic effects leading to widespread complications in the long run. As far as we know, there are a few studies for pollution monitoring and control systems in comparison with other environmental pollutants. One of the largest metropolitan cities located in Iran is Mashhad city as known as one of the biggest religious cities in the world. Different properties of this city including historical, industrial, and religious draw thousands of visitors to Mashhad, yearly. This fact motivates us to contribute to the concept of noise pollution in streets and sidewalks around the Holy Shrine, namely, Imam Reza. In this regard, different measurements using geographic information system (GIS) and descriptive statistical methods were conducted for our case study in Mashhad, Iran. All measurements and records were done during the peak of morning crowd (10-12 AM) and evening crowd (4-6 PM) on both sidewalks of each street around the Holy Shrine. This study showed that the pollution in the evening time span (4-6 PM) has the maximum level of noise. Among all streets in our case study in Mashhad, Iran, Tabarsi street has the most amount of noise pollution with a mean of 78 dB(A) for the mean intensity for each point, and Imam Reza street has the minimum amount of pollution with a mean of 72.75 dB(A). Our findings from the temporal perspective analysis confirm that the noise pollution peaks in the evening, when weather conditions are favorable. From the spatial perspective analysis, the most intensive noise pollution was observed around residential and accommodation land uses, which have the highest number of arterial routes towards the Holy Shrine.

PMID:35034306 | DOI:10.1007/s11356-022-18532-4

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Nevin Manimala Statistics

Database development and survival analysis in a clinical and historical cohort of dogs affected by myxomatous mitral valve disease treated or not with pimobendan using causal inference techniques

Vet Res Commun. 2022 Jan 16. doi: 10.1007/s11259-021-09875-3. Online ahead of print.

ABSTRACT

The aim of this work was to retrospectively evaluate the influence of pimobendan on the survival time (ST) of dogs with myxomatous mitral valve disease at different stages using an Inverse Probability Weighting (IPW) analysis. An IPW method was used to minimize confounding and IPW weighted time-repeated logistic model was used to approximate survival curves (SCs) and calculate survival differences. Subjects were allocated into exposed (E) and unexposed (U). Dogs in the American College of Veterinary Internal Medicine (ACVIM) B2 class treated with pimobendan (± ACE-inhibitors) were selected for the E group, as well as symptomatic patients (ACVIM class C) treated with triple (furosemide, ACE-inhibitor, pimobendan) or quadruple (furosemide, ACE-inhibitor, pimobendan and spironolactone) therapy. The U group included ACVIM class B2 dogs not treated with any medication and ACVIM C dogs treated with a combination of furosemide and ACE-inhibitor/spironolactone without pimobendan. The survival curve (SC) of the E group crossed the U group at 1634 days. The difference between the two SCs at the time of maximum survival difference in favor of the U group was 11.3% (CI 1.7%-20.9%) (significant), in favor of the E group was 3.9% (CI -8.6%-16.4%) (not significant) and at the mean ST was 3.6% (CI -8.5%-15.7%) (not significant) in favor of the E group. For times greater than 1634 days the survival was in favor of the E group, but there were no statistically significant differences in survival in favor of the E group in this clinical population.

PMID:35034282 | DOI:10.1007/s11259-021-09875-3

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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