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Nevin Manimala Statistics

Mapping the potential aggregation values of ecotourism landscapes from stakeholder survey, structural equation modeling and GIS: Case study of Moc Chau site, Vietnam

PLoS One. 2021 Jul 1;16(7):e0253908. doi: 10.1371/journal.pone.0253908. eCollection 2021.

ABSTRACT

The primary aim of this study is to propose a potential landscape value assessment from different dimensions rather than the traditional approach of a composite indicator. The method used in this study is the combination of data collection from stakeholder survey, score measurement for landscape value dimensions using Structural Equation Modeling (SEM), and spatial representation with the support of Geographic Information System (GIS). From a large-scale (n = 400) investigation in the Moc Chau district, the statistical data extracted from the survey provides input data for the score determination process. SEM analysis shows that each landscape site has 11 determinants influencing the landscape value assessment. Using the RMSE comparison (for validation) with different interpolation methods, the ordinary kriging method is chosen to model the aggregation landscape value map of Moc Chau District. About 24.97% total area of the study area has great potential for tourism development, being mainly distributed in the center of a high mountainous area. This approach can be used as a model to advocate local and regional assessment and enhance value-based management in other territories in Vietnam and beyond.

PMID:34197520 | DOI:10.1371/journal.pone.0253908

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Nevin Manimala Statistics

Accuracy of the Geriatric Depression Scale (GDS)-4 and GDS-5 for the screening of depression among older adults: A systematic review and meta-analysis

PLoS One. 2021 Jul 1;16(7):e0253899. doi: 10.1371/journal.pone.0253899. eCollection 2021.

ABSTRACT

BACKGROUND: The Geriatric Depression Scale (GDS) is a widely used instrument to assess depression in older adults. The short GDS versions that have four (GDS-4) and five items (GDS-5) represent alternatives for depression screening in limited-resource settings. However, their accuracy remains uncertain.

OBJECTIVE: To assess the accuracy of the GDS-4 and GDS-5 versions for depression screening in older adults.

METHODS: Until May 2020, we systematically searched PubMed, PsycINFO, Scopus, and Google Scholar; for studies that have assessed the sensitivity and specificity of GDS-4 and GDS-5 for depression screening in older adults. We conducted meta-analyses of the sensitivity and specificity of those studies that used the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the International Classification of Diseases-10 (ICD-10) as reference standard. Study quality was assessed with the QUADAS-2 tool. We performed bivariate random-effects meta-analyses to calculate the pooled sensitivity and specificity with their 95% confidence intervals (95% CI) at each reported common cut-off. For the overall meta-analyses, we evaluated each GDS-4 version or GDS-5 version separately by each cut-off, and for investigations of heterogeneity, we assessed altogether across similar GDS versions by each cut-off. Also, we assessed the certainty of evidence using the GRADE methodology.

RESULTS: Twenty-three studies were included and meta-analyzed, assessing eleven different GDS versions. The number of participants included was 5048. When including all versions together, at a cut-off 2, GDS-4 had a pooled sensitivity of 0.77 (95% CI: 0.70-0.82) and a pooled specificity of 0.75 (0.68-0.81); while GDS-5 had a pooled sensitivity of 0.85 (0.80-0.90) and a pooled specificity of 0.75 (0.69-0.81). We found results for more than one GDS-4 version at cut-off points 1, 2, and 3; and for more than one GDS-5 version at cut-off points 1, 2, 3, and 4. Mostly, significant subgroup differences at different test thresholds across versions were found. The accuracy of the different GDS-4 and GDS-5 versions showed a high heterogeneity. There was high risk of bias in the index test domain. Also, the certainty of the evidence was low or very low for most of the GDS versions.

CONCLUSIONS: We found several GDS-4 and GDS-5 versions that showed great heterogeneity in estimates of sensitivity and specificity, mostly with a low or very low certainty of the evidence. Altogether, our results indicate the need for more well-designed studies that compare different GDS versions.

PMID:34197527 | DOI:10.1371/journal.pone.0253899

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Nevin Manimala Statistics

Impact of metabolic syndrome and its components on bone remodeling in adolescents

PLoS One. 2021 Jul 1;16(7):e0253892. doi: 10.1371/journal.pone.0253892. eCollection 2021.

ABSTRACT

INTRODUCTION: Osteoporosis and metabolic syndrome (MetS) are diseases that have serious public health consequences, reducing the quality of life of patients and increasing morbidity and mortality, with substantial healthcare expenditures.

OBJECTIVE: To evaluate the impact of MetS on bone mineral density (BMD) and biochemical markers of bone formation and resorption in adolescents with excess weight.

METHOD: A descriptive and analytical cross-sectional study was performed that evaluated 271 adolescents of both sexes (10 to 16 years). From the total sample, 42 adolescents with excess weight and the presence of MetS (14%) were selected. A further 42 adolescents with excess weight and without MetS were chosen, matched for chronological age, bone age, and pubertal developmental criteria to those with MetS, for each sex. Anthropometric measurements, blood pressure collection, and biochemical tests were performed in all adolescents, as well as evaluation of BMD and the bone biomarkers osteocalcin (OC), bone alkaline phosphatase (BAP), and carboxy-terminal telopeptide (S-CTx).

RESULTS: The adolescents with excess weight and MetS exhibited significantly lower transformed BMD and concentrations of BAP, OC, and S-CTx compared to the matched group, except for OC in boys. A negative and significant correlation was observed between total body BMD and BAP (r = -0.55568; p = 0.005), OC (r = -0.81760; p = < .000), and S-CTx (r = -0.53838; p = 0.011) in girls.

CONCLUSION: Metabolic syndrome may be associated with reduced bone mineral density and biochemical markers of bone formation and resorption in adolescents with excess weight.

PMID:34197518 | DOI:10.1371/journal.pone.0253892

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Nevin Manimala Statistics

Conservation outreach that acknowledges human contributions to climate change does not inhibit action by U.S. farmers: Evidence from a large randomized controlled trial embedded in a federal program on soil health

PLoS One. 2021 Jul 1;16(7):e0253872. doi: 10.1371/journal.pone.0253872. eCollection 2021.

ABSTRACT

Technologies and practices that reduce the environmental impacts of US agriculture are well documented. Less is known about how best to encourage their adoption. We report on the results of a large randomized controlled trial conducted with nearly 10,000 agricultural producers in the United States. The experiment was embedded in US Department of Agriculture outreach efforts to improve soil conservation practices. USDA varied the content of mailings to test two sets of competing theories about outreach to agricultural producers. Contrary to conventional wisdom, we find no evidence that acknowledging the link between climate change and agricultural production discourages conservation action. Furthermore, we find that producers who were invited to a webinar were less likely to take any action to learn more about conservation practices than producers who were not told about the webinar, a result that runs counter to the popular wisdom that offering more options leads to more action.

PMID:34197511 | DOI:10.1371/journal.pone.0253872

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Nevin Manimala Statistics

Treatment seeking delay and associated factors among tuberculosis patients attending health facility in Ethiopia from 2000 to 2020: A systematic review and meta analysis

PLoS One. 2021 Jul 1;16(7):e0253746. doi: 10.1371/journal.pone.0253746. eCollection 2021.

ABSTRACT

BACKGROUND: Treatment seeking delay is defined as the time interval between the onset of the major symptoms of tuberculosis (TB) and the first visit to the formal health care facility. The patient was said to be delayed if the patient visited the health-facility after 3 weeks onset of major symptoms. However, in low-income countries like Ethiopia, the delay in treatment-seeking among tuberculosis patients contributes to a widespread transmission and high prevalence of tuberculosis.

METHODS: Studies were retrieved from PubMed, Cochrane Database, Cinahl, Scopus, Mednar, and Google Scholar by employing a combination of search terms with Boolean operators. Heterogeneity across studies was assessed using the Cochrane Q test. A funnel plot was used for visual assessment of publication bias. Subgroup analyses were performed to explore the possible causes of heterogeneity. Egger’s weighted regression test at a p-value < 0.05 was used to assess the presence of publication bias. Sensitivity analysis was performed to judge whether the pooled effect size was influenced by individual study. STATA software version 14 was used for all statistical analyses.

RESULT: A total of 12 studies with 5122 total sample size were included. The national pooled prevalence of treatment seeking delay was 44.29% (95% CI: 39.805, 48.771). The visual inspection of the funnel plot showed the asymmetrical distribution, and the Egger test showed insignificant (P = 0.348). Patients who did not seek formal health care providers on a first contact had about 7 times more likely to delay than patients who sought formal health care provider on a first contact (OR: 7.192 ((95% CI 5.587-9.257), P = 0.001, I2: 85%). The others independent predictors of delay were rural residence (OR: 3.459 ((95% CI 1.469-8.148), P ≤ 0.001), extra pulmonary TB (OR: 2.520 ((95% CI 1.761-3.605), 0.180), lower educational level (OR 11.720 ((95% CI 1.006-2.938), P <0.001), and distance more than 10km from health facility (OR: 1.631 ((95% CI (10.858-3.101), P = 0.001).

CONCLUSION: In this review, we identified a substantial treatment seeking delay among TB patients in Ethiopia. And, the independent predictors of delay were treatment sought before formal health care provider, residence of the patient, type of TB, educational level, and distance from a health facility. Thus, we recommend health extension workers, health professionals and other stakeholders to focus on patient education, and to continuously mobilize the whole communities on early treatment seeking with a special emphasis given to where treatment sought before formal health care provider, rural resident, extra pulmonary TB, and a patient living farther than 10km distance from health facility.

PMID:34197515 | DOI:10.1371/journal.pone.0253746

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Nevin Manimala Statistics

A normative database of A-scan data using the Heidelberg Spectralis Spectral Domain Optical Coherence Tomography machine

PLoS One. 2021 Jul 1;16(7):e0253720. doi: 10.1371/journal.pone.0253720. eCollection 2021.

ABSTRACT

PURPOSE: To develop the first normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.

METHODS: This study is a retrospective cross sectional analysis of macular and circumpapillary OCT scans of healthy individuals. All participants had a full ophthalmic examination, including best corrected visual acuity, intraocular pressure, biomicroscopy, posterior segment examination and OCT scan. The volume and thickness of each of the nine Early Treatment Diabetic Retinopathy zones at the macula were analysed for the total retinal thickness, retinal nerve fibre layer (RNFL), ganglion cell layer (GCL) and inner plexiform layer (IPL). The thickness of the circumpapillary RNFL was analysed at the disc. Associations between age, gender, refractive error and OCT measurements were explored. De-identified A-scans were extracted from the OCT machine as separate tab-separated text file and made available according to the data sharing statement.

RESULTS: Two-hundred eyes from 146 participants were included of which 69 (47%) were female. The mean age (SD) was 48.52 (17.52). Participants were evenly distributed across four age groups and represented nine broad ethnic groups in proportions comparable to the local distribution. All the macular scans were 20° x 20° (5.9 mm x 5.9 mm), with a total scan density between 12,800 and 49,152 A-scans. The peripapillary scans were all 12° (3.5 mm), at a scan density of 768 A-scans. The mean retinal, GCL and IPL volumes were significantly greater in males than females. Mean peripapillary RNFL thickness did not differ significantly between males and females. Age and total retinal volume (r = -0.2561, P = 0.0003), GCL volume (-0.2911, P < 0.0001) and IPL volume (-0.3194, P < 0.0001) were negatively correlated. The IPL had the strongest three significant negatively associated segments; superior inner IPL (r = -0.3444, P < 0.0001), nasal outer IPL (r = -0.3217, P < 0.0001) and inferior inner IPL (r = -0.3179, P < 0.0001). The temporal inner macular RNFL showed a statistically significant positive correlation (r = 0.1929, P = 0.0062) with age. The only significant association between age and thickness at the peripapillary disc scan was the superior temporal sector (r = -0.1910, P = 0.0067). All retinal layers were negatively correlated for refractive error, except for the central RNFL which was positively correlated (r = 0.1426, P = 0.044).

CONCLUSION: This study provides a normative database of macular and circumpapillary scans with reference values at the level of the A-scan using the Heidelberg Spectralis Optical Coherence Tomography (OCT) machine.

PMID:34197499 | DOI:10.1371/journal.pone.0253720

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Nevin Manimala Statistics

A transfer learning approach to facilitate ComBat-based harmonization of multicentre radiomic features in new datasets

PLoS One. 2021 Jul 1;16(7):e0253653. doi: 10.1371/journal.pone.0253653. eCollection 2021.

ABSTRACT

PURPOSE: To facilitate the demonstration of the prognostic value of radiomics, multicenter radiomics studies are needed. Pooling radiomic features of such data in a statistical analysis is however challenging, as they are sensitive to the variability in scanner models, acquisition protocols and reconstruction settings, which is often unavoidable in a multicentre retrospective analysis. A statistical harmonization strategy called ComBat was utilized in radiomics studies to deal with the “center-effect”. The goal of the present work was to integrate a transfer learning (TL) technique within ComBat-and recently developed alternate versions of ComBat with improved flexibility (M-ComBat) and robustness (B-ComBat)-to allow the use of a previously determined harmonization transform to the radiomic feature values of new patients from an already known center.

MATERIAL AND METHODS: The proposed TL approach were incorporated in the four versions of ComBat (standard, B, M, and B-M ComBat). The proposed approach was evaluated using a dataset of 189 locally advanced cervical cancer patients from 3 centers, with magnetic resonance imaging (MRI) and positron emission tomography (PET) images, with the clinical endpoint of predicting local failure. The impact performance of the TL approach was evaluated by comparing the harmonization achieved using only parts of the data to the reference (harmonization achieved using all the available data). It was performed through three different machine learning pipelines.

RESULTS: The proposed TL technique was successful in harmonizing features of new patients from a known center in all versions of ComBat, leading to predictive models reaching similar performance as the ones developed using the features harmonized with all the data available.

CONCLUSION: The proposed TL approach enables applying a previously determined ComBat transform to new, previously unseen data.

PMID:34197503 | DOI:10.1371/journal.pone.0253653

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Nevin Manimala Statistics

Upscaling human activity data: A statistical ecology approach

PLoS One. 2021 Jul 1;16(7):e0253461. doi: 10.1371/journal.pone.0253461. eCollection 2021.

ABSTRACT

Big data require new techniques to handle the information they come with. Here we consider four datasets (email communication, Twitter posts, Wikipedia articles and Gutenberg books) and propose a novel statistical framework to predict global statistics from random samples. More precisely, we infer the number of senders, hashtags and words of the whole dataset and how their abundances (i.e. the popularity of a hashtag) change through scales from a small sample of sent emails per sender, posts per hashtag and word occurrences. Our approach is grounded on statistical ecology as we map inference of human activities into the unseen species problem in biodiversity. Our findings may have applications to resource management in emails, collective attention monitoring in Twitter and language learning process in word databases.

PMID:34197484 | DOI:10.1371/journal.pone.0253461

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Nevin Manimala Statistics

Acute myocardial infarction: Development and application of an ICD-10-CM-based algorithm to a large U.S. healthcare claims-based database

PLoS One. 2021 Jul 1;16(7):e0253580. doi: 10.1371/journal.pone.0253580. eCollection 2021.

ABSTRACT

BACKGROUND: Healthcare administrative claims data hold value for monitoring drug safety and assessing drug effectiveness. The U.S. Food and Drug Administration Biologics Effectiveness and Safety Initiative (BEST) is expanding its analytical capacity by developing claims-based definitions-referred to as algorithms-for populations and outcomes of interest. Acute myocardial infarction (AMI) was of interest due to its potential association with select biologics and the lack of an externally validated International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) algorithm.

OBJECTIVE: Develop and apply an ICD-10-CM-based algorithm in a U.S. administrative claims database to identify and characterize AMI populations.

METHODS: A comprehensive literature review was conducted to identify validated AMI algorithms. Building on prior published methodology and consistent application of ICD-9-CM codes, an ICD-10-CM algorithm was developed via forward-backward mapping using General Equivalence Mappings and refined with clinical input. An AMI population was then identified in the IBM® MarketScan® Research Databases and characterized using descriptive statistics.

RESULTS AND DISCUSSION: Between 2014-2017, 2.83-3.16 individuals/1,000 enrollees/year received ≥1 AMI diagnosis in any healthcare setting. The 2015 transition to ICD-10-CM did not result in a substantial change in the proportion of patients identified. Average patient age at first AMI diagnosis was 64.9 years, and 61.4% of individuals were male. Unspecified chest pain, hypertension, and coronary atherosclerosis of native coronary vessel/artery were most commonly reported within one day of AMI diagnosis. Electrocardiograms were the most common medical procedure and beta-blockers were the most commonly ordered cardiac medication in the one day before to 14 days following AMI diagnosis. The mean length of inpatient stay was 5.6 days (median 3 days; standard deviation 7.9 days). Findings from this ICD-10-CM-based AMI study were internally consistent with ICD-9-CM-based findings and externally consistent with ICD-9-CM-based studies, suggesting that this algorithm is ready for validation in future studies.

PMID:34197488 | DOI:10.1371/journal.pone.0253580

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Nevin Manimala Statistics

Robust determinants of income distribution across and within countries

PLoS One. 2021 Jul 1;16(7):e0253291. doi: 10.1371/journal.pone.0253291. eCollection 2021.

ABSTRACT

Multicollinearity widely exists in empirical studies, which leads to imprecise estimation and even endogeneity when omitted variables are correlated with any regressors. We apply an innovative strategy, different from the usual tools (instrumental variable, ridge regression, and least absolute shrinkage and selection operator), to estimate the robust determinants of income distribution. We transform panel data into (quasi-) cross-sectional data by removing country and time effects from the data so that all variables become zero mean and orthogonal to the country dummies and time variable, and multicollinearity becomes very low or even disappears with the quasi-cross sectional data in any specifications regardless of country dummies and time variable being included or not. Our contribution is threefold. First, we build a general method to address the multicollinearity issue in panel data, which is to isolate the common contents of correlated variables and ensures robust estimates in different specifications (dynamic or static specifications) and estimators (within- or between-effects estimators). Second, we find no evidence for the Kuznets hypothesis within and across countries; investment is economically and statistically the most robust determinant of income inequality; meanwhile, labor income share shows robustly and consistently positive effects on income inequality, which challenges the related literature. Last, simulations with our estimates show that the total marginal effects of development (regarding GDP, capital stock and investment) on income inequality are very likely to be positive within and between countries except that the impacts on middle-60% and top-quintile income shares are not so likely to increase income inequality across countries.

PMID:34197494 | DOI:10.1371/journal.pone.0253291