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3.
Biom J ; 66(5): e202300197, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38953619

RESUMO

In biomedical research, the simultaneous inference of multiple binary endpoints may be of interest. In such cases, an appropriate multiplicity adjustment is required that controls the family-wise error rate, which represents the probability of making incorrect test decisions. In this paper, we investigate two approaches that perform single-step p $p$ -value adjustments that also take into account the possible correlation between endpoints. A rather novel and flexible approach known as multiple marginal models is considered, which is based on stacking of the parameter estimates of the marginal models and deriving their joint asymptotic distribution. We also investigate a nonparametric vector-based resampling approach, and we compare both approaches with the Bonferroni method by examining the family-wise error rate and power for different parameter settings, including low proportions and small sample sizes. The results show that the resampling-based approach consistently outperforms the other methods in terms of power, while still controlling the family-wise error rate. The multiple marginal models approach, on the other hand, shows a more conservative behavior. However, it offers more versatility in application, allowing for more complex models or straightforward computation of simultaneous confidence intervals. The practical application of the methods is demonstrated using a toxicological dataset from the National Toxicology Program.


Assuntos
Pesquisa Biomédica , Biometria , Modelos Estatísticos , Biometria/métodos , Pesquisa Biomédica/métodos , Tamanho da Amostra , Determinação de Ponto Final , Humanos
4.
Biom J ; 66(5): e202300075, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38953670

RESUMO

Closed testing has recently been shown to be optimal for simultaneous true discovery proportion control. It is, however, challenging to construct true discovery guarantee procedures in such a way that it focuses power on some feature sets chosen by users based on their specific interest or expertise. We propose a procedure that allows users to target power on prespecified feature sets, that is, "focus sets." Still, the method also allows inference for feature sets chosen post hoc, that is, "nonfocus sets," for which we deduce a true discovery lower confidence bound by interpolation. Our procedure is built from partial true discovery guarantee procedures combined with Holm's procedure and is a conservative shortcut to the closed testing procedure. A simulation study confirms that the statistical power of our method is relatively high for focus sets, at the cost of power for nonfocus sets, as desired. In addition, we investigate its power property for sets with specific structures, for example, trees and directed acyclic graphs. We also compare our method with AdaFilter in the context of replicability analysis. The application of our method is illustrated with a gene ontology analysis in gene expression data.


Assuntos
Biometria , Biometria/métodos , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Humanos
5.
Zhonghua Yan Ke Za Zhi ; 60(7): 601-610, 2024 Jul 11.
Artigo em Chinês | MEDLINE | ID: mdl-38955762

RESUMO

Objective: To investigate the characteristics of posterior segment lesions in Marfan syndrome (MFS) patients and their relationship with anterior segment biometric parameters and FBN1 genotype. Methods: A cross-sectional study was conducted. A total of 121 MFS patients, 76 males and 45 females, with an average age of (11.72±11.66) years, who visited the Department of Ophthalmology, Eye & ENT Hospital of Fudan University from January 2013 to March 2023 were included. The presence of posterior scleral staphyloma was observed using B-mode ultrasound, and macular lesions were identified and classified using the atrophy-traction-neovascularization system based on ultra-widefield fundus images, color fundus images, and optical coherence tomography scans. Anterior segment biometric parameters, including axial length of the eye, average corneal curvature, corneal astigmatism, horizontal corneal diameter, anterior chamber depth, and lens thickness, were collected, and the direction and extent of lens dislocation were observed. Molecular genetic analysis of FBN1 gene mutations in patients was performed using next-generation sequencing based on a panel of ocular genetic diseases, and the impact of the genotype and anterior segment biometric parameters on the posterior segment manifestations was analyzed. Results: Sixty patients exhibited posterior segment lesions, including retinal detachment (4 cases, 3.31%), macular lesions (47 cases, 38.84%), and posterior scleral staphyloma (54 cases, 44.63%). There was statistically significant difference in axial length of the eye between patients with and without posterior scleral staphyloma [23.09 (22.24, 24.43) and 27.04 (25.44, 28.88) mm], between patients with and without macular lesions [23.16 (22.24, 24.61) and 27.04 (25.74, 28.78) mm], and between patients with and without atrophic macular lesions [23.16 (22.24, 24.61) and 27.04 (25.74, 28.79) mm] (all P<0.001). There was statistically significant difference in anterior chamber depth between patients with and without macular lesions [3.11 (2.75, 3.30) and 3.34 (3.09, 3.60) mm] (P<0.05). There was also statistically significant difference in corneal astigmatism between patients with and without posterior scleral staphyloma [2.15 (1.20, 2.93) and 1.40 (1.00, 2.20) diopters] (P<0.05). The location and region of the FBN1 gene mutation not only showed statistically significant difference from the positive rates of posterior scleral staphyloma and macular lesions (all P<0.05), but also influenced the occurrence of atrophic macular lesions (both P<0.05). Patients with FBN1 mutations located in the transforming growth factor ß regulatory sequence had the highest proportion of posterior scleral staphyloma and macular lesions (both 10/11). Conclusions: Posterior scleral staphyloma and macular lesions have a relatively high incidence in MFS patients and tend to progress to more severe grades. The age, axial length of the eye, anterior chamber depth, corneal astigmatism, and location and region of the FBN1 gene mutation are factors affecting the posterior segment lesions in MFS patients.


Assuntos
Fibrilina-1 , Genótipo , Síndrome de Marfan , Humanos , Masculino , Feminino , Fibrilina-1/genética , Estudos Transversais , Síndrome de Marfan/genética , Criança , Adolescente , Segmento Anterior do Olho , Segmento Posterior do Olho/patologia , Mutação , Biometria , Adulto Jovem , Degeneração Macular/genética , Adipocinas
6.
J Contemp Dent Pract ; 25(4): 386-391, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38956855

RESUMO

AIM: To describe the bibliometric characteristics of the state of scientific production on dental caries during pregnancy. MATERIALS AND METHODS: A bibliometric study with a sample of 408 publications indexed in the Scopus database, which were selected based on a search strategy that included logical operators and the term MESH. The Scival tool was used to analyze the metadata. RESULTS: Jamieson Lisa Marie is positioned as the author with the most publications, and Schroth Robert as the one with the best-weighted impact (FWCI: 37.7). High-impact journals such as BMC Oral Health, Journal of Dental Research, and BMC Public Health stand out for their productivity and an average number of citations. The United States has a large number of publications and evidence of networks of scientific activity with Australia, Canada, and Brazil. The University of Adelaide leads the production and the work of two Latin American institutions (Universidade de São Paulo and Universidade Federal do Maranhão) stands out. International collaboration has improved during the study period. CONCLUSION: Scientific production on dental caries during pregnancy is increasingly published in high-impact journals, with growing international collaboration. The United States leads in publications, while Australian institutions are the most productive in this field. CLINICAL SIGNIFICANCE: Caries during pregnancy is a problem that has an important impact on maternal and perinatal health; thus, its timely management and prevention are important areas of research in the field of oral health. How to cite this article: Muñoz-Hidalgo M, Verastegui-Cabanillas Y, Barja-Ore J. Status of Research on Dental Caries during Pregnancy: A Biometric Exploration. J Contemp Dent Pract 2024;25(4):386-391.


Assuntos
Bibliometria , Cárie Dentária , Humanos , Cárie Dentária/epidemiologia , Gravidez , Feminino , Complicações na Gravidez/epidemiologia , Pesquisa em Odontologia/estatística & dados numéricos , Biometria
7.
Sci Data ; 11(1): 718, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956046

RESUMO

Handwritten signatures in biometric authentication leverage unique individual characteristics for identification, offering high specificity through dynamic and static properties. However, this modality faces significant challenges from sophisticated forgery attempts, underscoring the need for enhanced security measures in common applications. To address forgery in signature-based biometric systems, integrating a forgery-resistant modality, namely, noninvasive electroencephalography (EEG), which captures unique brain activity patterns, can significantly enhance system robustness by leveraging multimodality's strengths. By combining EEG, a physiological modality, with handwritten signatures, a behavioral modality, our approach capitalizes on the strengths of both, significantly fortifying the robustness of biometric systems through this multimodal integration. In addition, EEG's resistance to replication offers a high-security level, making it a robust addition to user identification and verification. This study presents a new multimodal SignEEG v1.0 dataset based on EEG and hand-drawn signatures from 70 subjects. EEG signals and hand-drawn signatures have been collected with Emotiv Insight and Wacom One sensors, respectively. The multimodal data consists of three paradigms based on mental, & motor imagery, and physical execution: i) thinking of the signature's image, (ii) drawing the signature mentally, and (iii) drawing a signature physically. Extensive experiments have been conducted to establish a baseline with machine learning classifiers. The results demonstrate that multimodality in biometric systems significantly enhances robustness, achieving high reliability even with limited sample sizes. We release the raw, pre-processed data and easy-to-follow implementation details.


Assuntos
Eletroencefalografia , Humanos , Escrita Manual , Identificação Biométrica/métodos , Biometria
8.
Biometrics ; 80(3)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38994639

RESUMO

What is the best way to split one stratum into two to maximally reduce the within-stratum imbalance in many covariates? We formulate this as an integer program and approximate the solution by randomized rounding of a linear program. A linear program may assign a fraction of a person to each refined stratum. Randomized rounding views fractional people as probabilities, assigning intact people to strata using biased coins. Randomized rounding is a well-studied theoretical technique for approximating the optimal solution of certain insoluble integer programs. When the number of people in a stratum is large relative to the number of covariates, we prove the following new results: (i) randomized rounding to split a stratum does very little randomizing, so it closely resembles the linear programming relaxation without splitting intact people; (ii) the linear relaxation and the randomly rounded solution place lower and upper bounds on the unattainable integer programming solution; and because of (i), these bounds are often close, thereby ratifying the usable randomly rounded solution. We illustrate using an observational study that balanced many covariates by forming matched pairs composed of 2016 patients selected from 5735 using a propensity score. Instead, we form 5 propensity score strata and refine them into 10 strata, obtaining excellent covariate balance while retaining all patients. An R package optrefine at CRAN implements the method. Supplementary materials are available online.


Assuntos
Pontuação de Propensão , Humanos , Modelos Estatísticos , Biometria/métodos , Simulação por Computador
9.
Biometrics ; 80(3)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38994640

RESUMO

We estimate relative hazards and absolute risks (or cumulative incidence or crude risk) under cause-specific proportional hazards models for competing risks from double nested case-control (DNCC) data. In the DNCC design, controls are time-matched not only to cases from the cause of primary interest, but also to cases from competing risks (the phase-two sample). Complete covariate data are available in the phase-two sample, but other cohort members only have information on survival outcomes and some covariates. Design-weighted estimators use inverse sampling probabilities computed from Samuelsen-type calculations for DNCC. To take advantage of additional information available on all cohort members, we augment the estimating equations with a term that is unbiased for zero but improves the efficiency of estimates from the cause-specific proportional hazards model. We establish the asymptotic properties of the proposed estimators, including the estimator of absolute risk, and derive consistent variance estimators. We show that augmented design-weighted estimators are more efficient than design-weighted estimators. Through simulations, we show that the proposed asymptotic methods yield nominal operating characteristics in practical sample sizes. We illustrate the methods using prostate cancer mortality data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Study of the National Cancer Institute.


Assuntos
Modelos de Riscos Proporcionais , Neoplasias da Próstata , Estudos de Casos e Controles , Humanos , Masculino , Medição de Risco/estatística & dados numéricos , Medição de Risco/métodos , Neoplasias da Próstata/mortalidade , Simulação por Computador , Interpretação Estatística de Dados , Biometria/métodos , Fatores de Risco
10.
Biometrics ; 80(3)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949889

RESUMO

The response envelope model proposed by Cook et al. (2010) is an efficient method to estimate the regression coefficient under the context of the multivariate linear regression model. It improves estimation efficiency by identifying material and immaterial parts of responses and removing the immaterial variation. The response envelope model has been investigated only for continuous response variables. In this paper, we propose the multivariate probit model with latent envelope, in short, the probit envelope model, as a response envelope model for multivariate binary response variables. The probit envelope model takes into account relations between Gaussian latent variables of the multivariate probit model by using the idea of the response envelope model. We address the identifiability of the probit envelope model by employing the essential identifiability concept and suggest a Bayesian method for the parameter estimation. We illustrate the probit envelope model via simulation studies and real-data analysis. The simulation studies show that the probit envelope model has the potential to gain efficiency in estimation compared to the multivariate probit model. The real data analysis shows that the probit envelope model is useful for multi-label classification.


Assuntos
Teorema de Bayes , Simulação por Computador , Modelos Estatísticos , Análise Multivariada , Humanos , Modelos Lineares , Biometria/métodos , Distribuição Normal
11.
J Refract Surg ; 40(7): e438-e444, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39007810

RESUMO

PURPOSE: To assess the influence of ocular biometric parameters on intraocular lens (IOL) tilt and decentration after cataract surgery. METHODS: Patients scheduled for cataract surgery were screened for inclusion in this prospective cohort study. Tilt and decentration of the crystalline lens and IOL were measured using the CASIA2 (Tomey). Anterior chamber depth (ACD), lens thickness (LT), and axial length (AL) were preoperatively measured by the IOLMaster 700 (Carl Zeiss Meditec AG). Multivariate regression analysis was performed to assess the influence of ocular biometric parameters on IOL tilt and decentration after cataract surgery. RESULTS: In total, 191 eyes of 120 patients were included. Age was positively correlated with IOL tilt, whereas ACD and AL were negatively correlated with IOL tilt. A strong positive correlation was found between preoperative crystalline lenses and postoperative IOLs in tilt magnitude (r = 0.769, P < .001) and tilt direction (r = 0.688, P < .001). A positive correlation was found between preoperative and postoperative lens decentration magnitude and decentration direction. Greater postoperative IOL tilt and decentration were significantly associated with greater preoperative crystalline lens tilt (P < .001) and decentration (P = .027). CONCLUSIONS: IOL tilt was greater in older patients. Shorter AL and shallower ACD contributed to greater IOL tilt. The tilt and decentration of the IOL will be greater in patients with greater tilt and decentration of the crystalline lens. [J Refract Surg. 2024;40(7):e438-e444.].


Assuntos
Comprimento Axial do Olho , Biometria , Implante de Lente Intraocular , Lentes Intraoculares , Facoemulsificação , Humanos , Estudos Prospectivos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Comprimento Axial do Olho/patologia , Idoso de 80 Anos ou mais , Câmara Anterior/patologia , Migração do Implante de Lente Intraocular/fisiopatologia , Cristalino , Acuidade Visual/fisiologia , Adulto , Pseudofacia/fisiopatologia
12.
J Refract Surg ; 40(7): e445-e452, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39007818

RESUMO

PURPOSE: To evaluate the repeatability of automatic measurements of a new anterior segment optical coherence tomographer (ANTERION; Heidelberg Engineering) and their agreement with an anterior segment optical coherence tomography device combined with Placido disc corneal topography (MS-39; CSO) in patients affected by keratoconus. METHODS: Fifty-four consecutive patients were included. Three measurements were performed with the ANTERION and one with the MS-39. Repeatability was assessed by means of within-subject standard deviation, coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Agreement was investigated with the 95% limits of agreement. The paired t-test and Wilcoxon matched-pairs test were performed to compare the measurements of the different devices. RESULTS: Repeatability of ANTERION measurements was high, with an ICC greater than 0.98 for all parameters. Many parameters revealed a CoV of less than 1% and a CoV within 5% was obtained for astigmatism measurements. The ANTERION measured a significantly higher corneal power and the MS-39 more negative posterior keratometric values. These differences were mirrored by a moderate agreement for mean simulated keratometry and poor agreement for total corneal power and posterior keratometry. CONCLUSIONS: The ANTERION revealed high repeatability of automatic measurements and good agreement with the MS-39 for many parameters in patients affected by keratoconus, but for most parameters the two instruments cannot be considered interchangeable. [J Refract Surg. 2024;40(7):e445-e452.].


Assuntos
Segmento Anterior do Olho , Topografia da Córnea , Ceratocone , Tomografia de Coerência Óptica , Humanos , Ceratocone/diagnóstico , Ceratocone/fisiopatologia , Tomografia de Coerência Óptica/métodos , Reprodutibilidade dos Testes , Adulto , Topografia da Córnea/métodos , Masculino , Feminino , Segmento Anterior do Olho/diagnóstico por imagem , Adulto Jovem , Biometria/instrumentação , Biometria/métodos , Estudos Prospectivos , Córnea/patologia , Córnea/diagnóstico por imagem , Pessoa de Meia-Idade , Adolescente
13.
Biom J ; 66(5): e202300386, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39001703

RESUMO

The concept of (potential) years of life lost is a measure of premature mortality that can be used to compare the impacts of different specific causes of death. However, interpreting a given number of years of life lost at face value is more problematic because of the lack of a sensible reference value. In this paper, we propose three denominators to divide an excess years of life lost, thus obtaining three indicators, called average life lost, increase of life lost, and proportion of life lost, which should facilitate interpretation and comparisons. We study the links between these three indicators and classical mortality indicators, such as life expectancy and standardized mortality rate, introduce the concept of weighted standardized mortality rate, and calculate them in 30 countries to assess the impact of COVID-19 on mortality in the year 2020. Using any of the three indicators, a significant excess loss is found for both genders in 18 of the 30 countries.


Assuntos
COVID-19 , Expectativa de Vida , COVID-19/mortalidade , COVID-19/epidemiologia , Humanos , Masculino , Feminino , Biometria/métodos , Idoso
14.
Biom J ; 66(5): e202300182, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39001709

RESUMO

Spatial count data with an abundance of zeros arise commonly in disease mapping studies. Typically, these data are analyzed using zero-inflated models, which comprise a mixture of a point mass at zero and an ordinary count distribution, such as the Poisson or negative binomial. However, due to their mixture representation, conventional zero-inflated models are challenging to explain in practice because the parameter estimates have conditional latent-class interpretations. As an alternative, several authors have proposed marginalized zero-inflated models that simultaneously model the excess zeros and the marginal mean, leading to a parameterization that more closely aligns with ordinary count models. Motivated by a study examining predictors of COVID-19 death rates, we develop a spatiotemporal marginalized zero-inflated negative binomial model that directly models the marginal mean, thus extending marginalized zero-inflated models to the spatial setting. To capture the spatiotemporal heterogeneity in the data, we introduce region-level covariates, smooth temporal effects, and spatially correlated random effects to model both the excess zeros and the marginal mean. For estimation, we adopt a Bayesian approach that combines full-conditional Gibbs sampling and Metropolis-Hastings steps. We investigate features of the model and use the model to identify key predictors of COVID-19 deaths in the US state of Georgia during the 2021 calendar year.


Assuntos
Teorema de Bayes , Biometria , COVID-19 , Modelos Estatísticos , Humanos , COVID-19/mortalidade , COVID-19/epidemiologia , Georgia/epidemiologia , Biometria/métodos , Análise Espacial , Distribuição Binomial
15.
Biom J ; 66(5): e202400027, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39001710

RESUMO

A generalization of Passing-Bablok regression is proposed for comparing multiple measurement methods simultaneously. Possible applications include assay migration studies or interlaboratory trials. When comparing only two methods, the method boils down to the usual Passing-Bablok estimator. It is close in spirit to reduced major axis regression, which is, however, not robust. To obtain a robust estimator, the major axis is replaced by the (hyper-)spherical median axis. This technique has been applied to compare SARS-CoV-2 serological tests, bilirubin in neonates, and an in vitro diagnostic test using different instruments, sample preparations, and reagent lots. In addition, plots similar to the well-known Bland-Altman plots have been developed to represent the variance structure.


Assuntos
Biometria , Humanos , Análise de Regressão , Biometria/métodos , Recém-Nascido , Bilirrubina/sangue , COVID-19 , Teste Sorológico para COVID-19/métodos , SARS-CoV-2
16.
Biom J ; 66(5): e202300081, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38966906

RESUMO

Motivated by improving the prediction of the human immunodeficiency virus (HIV) suppression status using electronic health records (EHR) data, we propose a functional multivariable logistic regression model, which accounts for the longitudinal binary process and continuous process simultaneously. Specifically, the longitudinal measurements for either binary or continuous variables are modeled by functional principal components analysis, and their corresponding functional principal component scores are used to build a logistic regression model for prediction. The longitudinal binary data are linked to underlying Gaussian processes. The estimation is done using penalized spline for the longitudinal continuous and binary data. Group-lasso is used to select longitudinal processes, and the multivariate functional principal components analysis is proposed to revise functional principal component scores with the correlation. The method is evaluated via comprehensive simulation studies and then applied to predict viral suppression using EHR data for people living with HIV in South Carolina.


Assuntos
Infecções por HIV , Humanos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Modelos Logísticos , Análise Multivariada , Biometria/métodos , Registros Eletrônicos de Saúde , Carga Viral , Análise de Componente Principal
17.
Biom J ; 66(5): e202300167, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988194

RESUMO

In the individual stepped-wedge randomized trial (ISW-RT), subjects are allocated to sequences, each sequence being defined by a control period followed by an experimental period. The total follow-up time is the same for all sequences, but the duration of the control and experimental periods varies among sequences. To our knowledge, there is no validated sample size calculation formula for ISW-RTs unlike stepped-wedge cluster randomized trials (SW-CRTs). The objective of this study was to adapt the formula used for SW-CRTs to the case of individual randomization and to validate this adaptation using a Monte Carlo simulation study. The proposed sample size calculation formula for an ISW-RT design yielded satisfactory empirical power for most scenarios except scenarios with operating characteristic values near the boundary (i.e., smallest possible number of periods, very high or very low autocorrelation coefficient). Overall, the results provide useful insights into the sample size calculation for ISW-RTs.


Assuntos
Método de Monte Carlo , Ensaios Clínicos Controlados Aleatórios como Assunto , Tamanho da Amostra , Humanos , Biometria/métodos
18.
Biom J ; 66(5): e202300278, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988195

RESUMO

Rapid advances in high-throughput DNA sequencing technologies have enabled large-scale whole genome sequencing (WGS) studies. Before performing association analysis between phenotypes and genotypes, preprocessing and quality control (QC) of the raw sequence data need to be performed. Because many biostatisticians have not been working with WGS data so far, we first sketch Illumina's short-read sequencing technology. Second, we explain the general preprocessing pipeline for WGS studies. Third, we provide an overview of important QC metrics, which are applied to WGS data: on the raw data, after mapping and alignment, after variant calling, and after multisample variant calling. Fourth, we illustrate the QC with the data from the GENEtic SequencIng Study Hamburg-Davos (GENESIS-HD), a study involving more than 9000 human whole genomes. All samples were sequenced on an Illumina NovaSeq 6000 with an average coverage of 35× using a PCR-free protocol. For QC, one genome in a bottle (GIAB) trio was sequenced in four replicates, and one GIAB sample was successfully sequenced 70 times in different runs. Fifth, we provide empirical data on the compression of raw data using the DRAGEN original read archive (ORA). The most important quality metrics in the application were genetic similarity, sample cross-contamination, deviations from the expected Het/Hom ratio, relatedness, and coverage. The compression ratio of the raw files using DRAGEN ORA was 5.6:1, and compression time was linear by genome coverage. In summary, the preprocessing, joint calling, and QC of large WGS studies are feasible within a reasonable time, and efficient QC procedures are readily available.


Assuntos
Controle de Qualidade , Sequenciamento Completo do Genoma , Humanos , Biometria/métodos , Bioestatística/métodos , Sequenciamento de Nucleotídeos em Larga Escala
19.
Biom J ; 66(5): e202300200, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38988210

RESUMO

Spatial scan statistics are well-known methods widely used to detect spatial clusters of events. Furthermore, several spatial scan statistics models have been applied to the spatial analysis of time-to-event data. However, these models do not take account of potential correlations between the observations of individuals within the same spatial unit or potential spatial dependence between spatial units. To overcome this problem, we have developed a scan statistic based on a Cox model with shared frailty and that takes account of the spatial dependence between spatial units. In simulation studies, we found that (i) conventional models of spatial scan statistics for time-to-event data fail to maintain the type I error in the presence of a correlation between the observations of individuals within the same spatial unit and (ii) our model performed well in the presence of such correlation and spatial dependence. We have applied our method to epidemiological data and the detection of spatial clusters of mortality in patients with end-stage renal disease in northern France.


Assuntos
Biometria , Modelos Estatísticos , Humanos , Biometria/métodos , Falência Renal Crônica/epidemiologia , Fragilidade/epidemiologia , Fatores de Tempo , Modelos de Riscos Proporcionais , Análise Espacial
20.
Biometrics ; 80(3)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39011739

RESUMO

Electronic health records and other sources of observational data are increasingly used for drawing causal inferences. The estimation of a causal effect using these data not meant for research purposes is subject to confounding and irregularly-spaced covariate-driven observation times affecting the inference. A doubly-weighted estimator accounting for these features has previously been proposed that relies on the correct specification of two nuisance models used for the weights. In this work, we propose a novel consistent multiply robust estimator and demonstrate analytically and in comprehensive simulation studies that it is more flexible and more efficient than the only alternative estimator proposed for the same setting. It is further applied to data from the Add Health study in the United States to estimate the causal effect of therapy counseling on alcohol consumption in American adolescents.


Assuntos
Simulação por Computador , Modelos Estatísticos , Estudos Observacionais como Assunto , Humanos , Estudos Observacionais como Assunto/estatística & dados numéricos , Adolescente , Causalidade , Estados Unidos , Interpretação Estatística de Dados , Registros Eletrônicos de Saúde/estatística & dados numéricos , Biometria/métodos , Consumo de Bebidas Alcoólicas
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