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1.
J Cancer Educ ; 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963602

RESUMO

Oropharyngeal human papillomavirus (HPV) cancers are prevalent, but HPV education in dental clinics is uncommon. The purpose of this study was to evaluate dental provider and patient knowledge from, attitudes towards, and preferences for HPV education, then assess perceptions of existing HPV educational materials for use at dental visits. Appalachian Ohio dental patients (n = 13) and general/pediatric dental providers (n = 10) completed an initial, close-ended survey on current HPV knowledge and HPV educational attitudes, participation, and resource preferences. Select individuals reviewed existing HPV educational videos and toolkits via virtual focus groups (n = 9) or independent review surveys (n = 6). Using a discussion guide, participants responded to overall, visual, auditory, and content satisfaction statements, orally (focus groups) or with Likert scales (independent reviews). Surveys were summarized with frequencies/percentages; transcripts were qualitatively coded to identify potential material modifications. Dental providers and patients were more comfortable with HPV and oral cancer education (87% and 96%, respectively) and screening (96%) than with HPV vaccine education (74%) and referrals (61%) during dental visits. Providers were neither sharing HPV educational materials (80%) nor initiating educational conversations with dental patients (100%). The American Cancer Society videos and the "Team Maureen" toolkit were the most liked resources (i.e., fewer negative/disagree statements) by all participant groups. Findings indicate that future dental HPV educational efforts should be informed by currently available materials. Additional interventions are needed to promote dental provider discussions and sharing of educational materials with patients to increase education and promotion of the HPV vaccine and reduce oropharyngeal cancers.

2.
Stat Med ; 41(1): 17-36, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34658053

RESUMO

Many prospective biomedical studies collect longitudinal clinical and lifestyle data that are both continuous and discrete. In some studies, there is interest in the association between a binary outcome and the values of these longitudinal measurements at a specific time point. A common problem in these studies is inconsistency in timing of measurements and missing follow-ups which can lead to few measurements at the time of interest. Some methods have been developed to address this problem, but are only applicable to continuous measurements. To address this limitation, we propose a new class of joint models for a binary outcome and longitudinal explanatory variables of mixed types. The longitudinal model uses a latent normal random variable construction with regression splines to model time-dependent trends in mean with a Dirichlet Process prior assigned to random effects to relax distribution assumptions. We also standardize timing of the explanatory variables by relating the binary outcome to imputed longitudinal values at a set time point. The proposed model is evaluated through simulation studies and applied to data from a cancer survivor study of participants in the Women's Health Initiative.


Assuntos
Modelos Estatísticos , Teorema de Bayes , Simulação por Computador , Feminino , Humanos , Estudos Longitudinais , Estudos Prospectivos
3.
Lifetime Data Anal ; 27(1): 177-194, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33420544

RESUMO

Time-to-event data often violate the proportional hazards assumption inherent in the popular Cox regression model. Such violations are especially common in the sphere of biological and medical data where latent heterogeneity due to unmeasured covariates or time varying effects are common. A variety of parametric survival models have been proposed in the literature which make more appropriate assumptions on the hazard function, at least for certain applications. One such model is derived from the First Hitting Time (FHT) paradigm which assumes that a subject's event time is determined by a latent stochastic process reaching a threshold value. Several random effects specifications of the FHT model have also been proposed which allow for better modeling of data with unmeasured covariates. While often appropriate, these methods often display limited flexibility due to their inability to model a wide range of heterogeneities. To address this issue, we propose a Bayesian model which loosens assumptions on the mixing distribution inherent in the random effects FHT models currently in use. We demonstrate via simulation study that the proposed model greatly improves both survival and parameter estimation in the presence of latent heterogeneity. We also apply the proposed methodology to data from a toxicology/carcinogenicity study which exhibits nonproportional hazards and contrast the results with both the Cox model and two popular FHT models.


Assuntos
Teorema de Bayes , Análise de Sobrevida , Algoritmos , Animais , Camundongos , Modelos de Riscos Proporcionais , Processos Estocásticos , Uretana/toxicidade
4.
Biol Blood Marrow Transplant ; 26(1): 7-15, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31445183

RESUMO

Autologous stem cell transplant (ASCT) is the standard of care for patients with multiple myeloma (MM). The clinical significance of peripheral blood T lymphocyte (PBTL) immunologic changes associated with ASCT is poorly understood. Here we evaluated T cell transcriptional messenger RNA profiles and immunophenotypes to correlate immunologic senescence, exhaustion, and anergy with clinical endpoints in a cohort of patients with MM undergoing ASCT. ASCT induced global transcriptional T cell changes and altered molecular levels of markers of T cell subtypes, T cell activation, and exhaustion. These included reduced CD4/CD8 ratio, skewing toward the Th1 subset, reduced expression of costimulatory receptors CD27 and CD28, heightened T cell activation, and increased expression of immune modulatory molecules LAG3 and PD1. Multicolor flow cytometry experiments confirmed altered circulating CD4 and CD8 subsets and skewing toward differentiated effector cells. Moreover, ASCT promoted an exhausted immunophenotype in CD3+CD4+ subsets and a senescent immunophenotype in CD3+CD8+ subsets. Subset-specific altered expression was also seen for surface molecules with immunomodulatory function. ASCT affected soluble levels of molecules with immunomodulatory function by increasing plasma HVEM and TIM3. High molecular LAG3 level was associated with inferior event-free survival post-ASCT (hazard ratio = 5.44; confidence interval, 1.92 to 15.46; P = .001; adjusted P [controlling for false discovery rate] = .038). Using a comprehensive evaluation of PBTLs on a molecular and phenotypic level, we have identified that ASCT induces global T cell alterations with CD4 and CD8 subset-specific changes. Moreover, LAG3 emerged as an early biomarker of adverse events post-ASCT. These findings will support the development of treatment strategies targeting immune defects in MM to augment or restore T cell responses.


Assuntos
Antígenos CD/imunologia , Biomarcadores Tumorais/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Perfilação da Expressão Gênica , Ativação Linfocitária , Mieloma Múltiplo/imunologia , Proteínas de Neoplasias/imunologia , Adulto , Idoso , Antígenos CD/sangue , Autoenxertos , Biomarcadores Tumorais/sangue , Relação CD4-CD8 , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/sangue , Mieloma Múltiplo/terapia , Proteínas de Neoplasias/sangue , Estudos Prospectivos , Proteína do Gene 3 de Ativação de Linfócitos
5.
Cancer Causes Control ; 31(10): 905-914, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32748100

RESUMO

PURPOSE: Research on HPV vaccine coverage in the United States has typically aggregated Hispanic/Latinx individuals into a single group for analyses, an approach that has potentially masked variation between Hispanic/Latinx subgroups. To address this limitation, we examined HPV vaccine coverage across Hispanic/Latinx subgroups. METHODS: We analyzed data on Hispanic/Latinx adolescents ages 13-17 (n = 16,335) from the 2012-2016 National Immunization Survey-Teen. Each adolescent was categorized into a subgroup: Mexican, Cuban, Puerto Rican, Central American, South American, other Spanish origin, or multi-subgroup. We examined HPV vaccine initiation (receipt of one or more doses) and completion (receipt of three doses) for males and females separately. Analyses used weighted logistic regression. RESULTS: Vaccine coverage among males was highest among Central Americans (initiation: 57.5%; completion: 31.1%) and lowest among multi-subgroup males (initiation: 46.3%; completion: 19.9%). Among females, initiation ranged from 63.4% among Cubans to 71.2% among Puerto Ricans, and completion ranged from 33.6% among multi-subgroup females to 48.7% among South Americans. Hispanic/Latinx subgroups were similar on these outcomes in regression models. However, within several subgroups, vaccine coverage was higher among adolescents whose parents' preferred language was Spanish (i.e., potentially less acculturated) compared to those whose parents' preferred language was English. CONCLUSIONS: Modest variation in HPV vaccine coverage exists across Hispanic/Latinx subgroups, with differences found by preferred language within several subgroups. Findings provide insight into HPV vaccine coverage among Hispanic/Latinx subgroups and can help guide future surveillance efforts and vaccination interventions.


Assuntos
Hispânico ou Latino/estatística & dados numéricos , Vacinas contra Papillomavirus/administração & dosagem , Vacinação/estatística & dados numéricos , Adolescente , Feminino , Inquéritos Epidemiológicos , Humanos , Modelos Logísticos , Masculino , Infecções por Papillomavirus/prevenção & controle , Estados Unidos/etnologia
6.
Biometrics ; 76(2): 549-560, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32134502

RESUMO

Evaluating the goodness of fit of logistic regression models is crucial to ensure the accuracy of the estimated probabilities. Unfortunately, such evaluation is problematic in large samples. Because the power of traditional goodness of fit tests increases with the sample size, practically irrelevant discrepancies between estimated and true probabilities are increasingly likely to cause the rejection of the hypothesis of perfect fit in larger and larger samples. This phenomenon has been widely documented for popular goodness of fit tests, such as the Hosmer-Lemeshow test. To address this limitation, we propose a modification of the Hosmer-Lemeshow approach. By standardizing the noncentrality parameter that characterizes the alternative distribution of the Hosmer-Lemeshow statistic, we introduce a parameter that measures the goodness of fit of a model but does not depend on the sample size. We provide the methodology to estimate this parameter and construct confidence intervals for it. Finally, we propose a formal statistical test to rigorously assess whether the fit of a model, albeit not perfect, is acceptable for practical purposes. The proposed method is compared in a simulation study with a competing modification of the Hosmer-Lemeshow test, based on repeated subsampling. We provide a step-by-step illustration of our method using a model for postneonatal mortality developed in a large cohort of more than 300 000 observations.


Assuntos
Modelos Logísticos , Modelos Estatísticos , Biometria , Distribuição de Qui-Quadrado , Simulação por Computador , Intervalos de Confiança , Feminino , Humanos , Lactente , Mortalidade Infantil , Modelos Lineares , Masculino , Método de Monte Carlo , Ohio/epidemiologia , Probabilidade , Tamanho da Amostra
7.
Knee Surg Sports Traumatol Arthrosc ; 27(8): 2643-2652, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30446784

RESUMO

PURPOSE: The purpose was to test the following hypotheses: (1) magnetic resonance imaging (MRI) markers of early knee cartilage degeneration would be present in the involved limb of young athletes after anterior cruciate ligament reconstruction (ACLR) and (2) poor knee function would be associated with MRI markers of cartilage degeneration. METHODS: Twenty-five young athletes after primary, unilateral ACLR (mean age, 16.7 years) were followed to 5-year post-return-to-sport (RTS) clearance, as a part of a larger, prospective cohort study in young athletes post-ACLR. At 2-year post-RTS, patient-reported knee function was evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS). At 5-year post-RTS, qualitative MRI sequences (3 T) and quantitative T1rho and T2 maps segmented into six regions at the femur and tibia were performed for the involved and uninvolved knee cartilages. Relaxation times were compared between knees using Holm-corrected paired t tests. Linear regression was used to examine the association between KOOS scores at 2 years and relaxation times at 5 years. RESULTS: Elevated T1rho and T2 relaxation times were observed in the involved knee at the anterior medial femoral condyle compared to the uninvolved knee (p = 0.006, p = 0.024, respectively). Lower KOOS-Pain, KOOS-Symptoms, KOOS-ADL, and KOOS-Sport scores at 2-year post-RTS were associated with higher T1rho or T2 relaxation times in various regions of the involved knee at 5-year post-RTS (all p < 0.05). CONCLUSIONS: MRI markers of early cartilage degeneration were identified in the medial compartment of the involved knee in young athletes 5-year post-RTS after ACLR. Lower KOOS scores at 2-year post-RTS were associated with elevated knee cartilage T1rho and T2 relaxation times at 5-year post-RTS. Evaluating patient-reported function over time after ACLR appears to provide insight into future degenerative changes in the knee cartilage matrix.


Assuntos
Reconstrução do Ligamento Cruzado Anterior , Cartilagem Articular/diagnóstico por imagem , Articulação do Joelho/diagnóstico por imagem , Volta ao Esporte , Adolescente , Lesões do Ligamento Cruzado Anterior/cirurgia , Atletas , Feminino , Fêmur/cirurgia , Humanos , Joelho/cirurgia , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Modelos Lineares , Imageamento por Ressonância Magnética/métodos , Masculino , Medidas de Resultados Relatados pelo Paciente , Estudos Prospectivos , Recuperação de Função Fisiológica , Tíbia/cirurgia , Adulto Jovem
8.
BMC Cancer ; 18(1): 867, 2018 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-30176814

RESUMO

BACKGROUND: The Ki67 Index has been extensively studied as a prognostic biomarker in breast cancer. However, its clinical adoption is largely hampered by the lack of a standardized method to assess Ki67 that limits inter-laboratory reproducibility. It is important to standardize the computation of the Ki67 Index before it can be effectively used in clincial practice. METHOD: In this study, we develop a systematic approach towards standardization of the Ki67 Index. We first create the ground truth consisting of tumor positive and tumor negative nuclei by registering adjacent breast tissue sections stained with Ki67 and H&E. The registration is followed by segmentation of positive and negative nuclei within tumor regions from Ki67 images. The true Ki67 Index is then approximated with a linear model of the area of positive to the total area of tumor nuclei. RESULTS: When tested on 75 images of Ki67 stained breast cancer biopsies, the proposed method resulted in an average root mean square error of 3.34. In comparison, an expert pathologist resulted in an average root mean square error of 9.98 and an existing automated approach produced an average root mean square error of 5.64. CONCLUSIONS: We show that it is possible to approximate the true Ki67 Index accurately without detecting individual nuclei and also statically demonstrate the weaknesses of commonly adopted approaches that use both tumor and non-tumor regions together while compensating for the latter with higher order approximations.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Antígeno Ki-67/genética , Prognóstico , Biópsia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Proliferação de Células/genética , Feminino , Humanos , Processamento de Imagem Assistida por Computador
9.
Cytometry A ; 91(6): 609-621, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28110507

RESUMO

The advance of high resolution digital scans of pathology slides allowed development of computer based image analysis algorithms that may help pathologists in IHC stains quantification. While very promising, these methods require further refinement before they are implemented in routine clinical setting. Particularly critical is to evaluate algorithm performance in a setting similar to current clinical practice. In this article, we present a pilot study that evaluates the use of a computerized cell quantification method in the clinical estimation of CD3 positive (CD3+) T cells in follicular lymphoma (FL). Our goal is to demonstrate the degree to which computerized quantification is comparable to the practice of estimation by a panel of expert pathologists. The computerized quantification method uses entropy based histogram thresholding to separate brown (CD3+) and blue (CD3-) regions after a color space transformation. A panel of four board-certified hematopathologists evaluated a database of 20 FL images using two different reading methods: visual estimation and manual marking of each CD3+ cell in the images. These image data and the readings provided a reference standard and the range of variability among readers. Sensitivity and specificity measures of the computer's segmentation of CD3+ and CD- T cell are recorded. For all four pathologists, mean sensitivity and specificity measures are 90.97 and 88.38%, respectively. The computerized quantification method agrees more with the manual cell marking as compared to the visual estimations. Statistical comparison between the computerized quantification method and the pathologist readings demonstrated good agreement with correlation coefficient values of 0.81 and 0.96 in terms of Lin's concordance correlation and Spearman's correlation coefficient, respectively. These values are higher than most of those calculated among the pathologists. In the future, the computerized quantification method may be used to investigate the relationship between the overall architectural pattern (i.e., interfollicular vs. follicular) and outcome measures (e.g., overall survival, and time to treatment). © 2017 International Society for Advancement of Cytometry.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Linfoma Folicular/diagnóstico , Linfócitos T/patologia , Automação Laboratorial , Complexo CD3/genética , Entropia , Expressão Gênica , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imuno-Histoquímica/métodos , Linfoma Folicular/genética , Linfoma Folicular/patologia , Linfoma Folicular/ultraestrutura , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coloração e Rotulagem/métodos , Linfócitos T/ultraestrutura
10.
Health Promot Pract ; 18(2): 201-210, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27178838

RESUMO

The purpose of this study is to provide process data from campaigns (2009-2010) to improve colorectal cancer (CRC; intervention) screening and fruit and vegetable (F&V; comparison) consumption in 12 Appalachian Ohio counties. County-specific campaigns included one billboard, posters, and articles for local newspapers. Participants in CRC screening counties who reported seeing CRC screening billboards had greater intention to talk to a doctor/nurse about screening in the next 6 months (odds ratio [OR] = 2.92, 95% confidence interval [CI; 1.71, 4.99]) and had twice the odds of talking to a doctor/nurse about screening in the past year (OR = 2.15, 95% CI [1.29, 3.60]) compared to those who did not see the billboards. Participants in F&V counties who reported seeing F&V billboards had twice the odds (OR = 2.27, 95% CI [1.35, 3.84]) of talking to a doctor/nurse in the past year about F&Vs compared to those who did not see the billboards. Participants who reported campaign exposure lived closer to the billboards compared to those who did not report campaign exposure (mean distance in miles from home to billboard: 8.8 vs. 10.9; p < .01). Most participants reported campaign messages were clear and important. Results suggest that partnering with community members to develop campaign materials is important to ensure cultural appropriateness and that exposure to the intervention components may affect health-related outcomes.


Assuntos
Neoplasias Colorretais/diagnóstico , Dieta Saudável , Detecção Precoce de Câncer/psicologia , Promoção da Saúde/organização & administração , Meios de Comunicação de Massa , Idoso , Região dos Apalaches , Feminino , Frutas , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Razão de Chances , Ohio , Fatores Socioeconômicos , Verduras
11.
Health Care Manage Rev ; 41(1): 32-41, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25029512

RESUMO

BACKGROUND: Although patient handoffs have been extensively studied, they continue to be problematic. Studies have shown poor handoffs are associated with increased costs, morbidity, and mortality. No prior research compared perceptions of management and clinical staff regarding handoffs. PURPOSE: Our aims were (a) to determine whether perceptions of organizational factors that can influence patient safety are positively associated with perceptions of successful patient handoffs, (b) to identify organizational factors that have the greatest influence on perceptions of successful handoffs, and (c) to determine whether associations between perceptions of these factors and successful handoffs differ for management and clinical staff. METHODOLOGY/APPROACH: A total of 515,637 respondents from 1,052 hospitals completed the Hospital Survey on Patient Safety Culture that assessed perceptions about organizational factors that influence patient safety. Using weighted least squares multiple regression, we tested seven organizational factors as predictors of successful handoffs. We fit three separate models using data collected from (a) all staff, (b) management only, and (c) clinical staff only. FINDINGS: We found that perceived teamwork across units was the most significant predictor of perceived successful handoffs. Perceptions of staffing and management support for safety were also significantly associated with perceived successful handoffs for both management and clinical staff. For management respondents, perceptions of organizational learning or continuous improvement had a significant positive association with perceived successful handoffs, whereas the association was negative for clinical staff. Perceived communication openness had a significant association only among clinical staff. PRACTICE IMPLICATIONS: Hospitals should prioritize teamwork across units and strive to improve communication across the organization in efforts to improve handoffs. In addition, hospitals should ensure sufficient staffing and management support for patient safety. Different perceptions between management and clinical staff with respect to the importance of organizational learning are noteworthy and merit additional study.


Assuntos
Cultura Organizacional , Transferência da Responsabilidade pelo Paciente/normas , Segurança do Paciente , Comunicação , Administração Hospitalar , Humanos , Liderança , Equipe de Assistência ao Paciente/normas , Gestão da Segurança , Inquéritos e Questionários
12.
J Vasc Surg ; 61(6): 1556-64, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24674272

RESUMO

OBJECTIVE: Iron has been implicated in atherogenesis and plaque destabilization, whereas less is known about iron-related proteins in this disease. We compared ex vivo quantities with in vivo vessel wall T2*, which is a noncontrast magnetic resonance relaxation time that quantitatively shortens with increased tissue iron content. We also tested the hypothesis that patients with carotid atherosclerosis have abnormal T2* times vs controls that would help support a role for iron in human atherosclerosis. METHODS: Forty-six patients undergoing carotid endarterectomy and 14 subjects without carotid disease were prospectively enrolled to undergo carotid magnetic resonance imaging. Ex vivo measurements were performed on explanted plaque and 17 mammary artery samples. RESULTS: Plaques vs normal arteries had higher levels of ferritin (median, 7.3 [interquartile range (IQR), 4-13.8] vs 1.0 [IQR, 0.6-1.3] ng/mg; P < .001) and oxidized low-density lipoprotein (median, 0.17 [IQR, 0.12-0.30] vs 0.01 [IQR, 0.003-0.03] ng/mg; P < .001) as well as hepcidin (median, 8.7 [IQR, 4.6-12.4] vs 2.6 [IQR, 1.3-7.0] ng/mL; P = .03); serum hepcidin levels did not distinguish atherosclerosis patients from controls (median, 40.6 [IQR, 18.8-88.6] vs 33.9 [IQR, 17.6-55.2]; P = .42). Shorter in vivo T2* paralleled larger plaque volume (ρ = -.44; P = .01), and diseased arteries had shorter T2* values compared with controls (median, 17.7 ± 4.3 vs 23.0 ± 2.4 ms; P < .001). CONCLUSIONS: Diseased arteries have greater levels of iron-related proteins ex vivo and shorter T2* times in vivo. Further studies should help define the role of T2* as a biomarker of iron and atherosclerosis.


Assuntos
Artérias Carótidas/química , Doenças das Artérias Carótidas/metabolismo , Ferro/análise , Angiografia por Ressonância Magnética , Placa Aterosclerótica , Idoso , Biomarcadores/análise , Artérias Carótidas/patologia , Artérias Carótidas/cirurgia , Doenças das Artérias Carótidas/patologia , Doenças das Artérias Carótidas/cirurgia , Estudos de Casos e Controles , Endarterectomia das Carótidas , Feminino , Ferritinas/análise , Hepcidinas/análise , Humanos , Lipoproteínas LDL/análise , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos
14.
J Public Health (Oxf) ; 37(2): 322-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24850101

RESUMO

BACKGROUND: Limited data are available on the association between colorectal cancer (CRC) worry and CRC screening uptake, particularly in rural and underserved populations where there is an excess burden of CRC. METHODS: Between September 2009 and March 2010, we conducted a cross-sectional study among a randomly selected sample of Appalachian Ohio residents aged 51-75 years (n= 1084). We also reviewed their medical records. Multivariable-adjusted models examined the association between CRC worry and screening by medical record review, assessed effect modification by CRC worry and determined the correlates of higher CRC worry. RESULTS: Approximately 50% of participants were adherent to CRC screening guidelines. There was no significant association between higher CRC worry and screening adherence [odds ratio (OR) = 1.32, 95% confidence interval (CI): 0.86-2.02]. CRC worry did not modify the association between any covariate and screening adherence. Participants who were unemployed/disabled (OR = 2.15, 95% CI: 1.34-3.45) and had higher CRC risk perception (OR = 3.49, 95% CI: 2.19-5.56) had higher odds of moderate-to-extreme worry. CONCLUSIONS: These findings highlight the need for meaningful exploration of why higher CRC worry is not associated with adherence to CRC screening, particularly in rural, medically underserved populations. Development and implementation of interventions to increase CRC screening in such areas is a significant public health priority.


Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/psicologia , Programas de Rastreamento , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Idoso , Neoplasias Colorretais/epidemiologia , Estudos Transversais , Feminino , Fidelidade a Diretrizes , Humanos , Masculino , Pessoa de Meia-Idade , Ohio/epidemiologia
15.
BMC Med Inform Decis Mak ; 15: 115, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26715518

RESUMO

BACKGROUND: Follicular lymphoma (FL) is one of the most common lymphoid malignancies in the western world. FL cases are stratified into three histological grades based on the average centroblast count per high power field (HPF). The centroblast count is performed manually by the pathologist using an optical microscope and hematoxylin and eosin (H&E) stained tissue section. Although this is the current clinical practice, it suffers from high inter- and intra-observer variability and is vulnerable to sampling bias. METHODS: In this paper, we present a system, called Follicular Lymphoma Grading System (FLAGS), to assist the pathologist in grading FL cases. We also assess the effect of FLAGS on accuracy of expert and inexperienced readers. FLAGS automatically identifies possible HPFs for examination by analyzing H&E and CD20 stains, before classifying them into low or high risk categories. The pathologist is first asked to review the slides according to the current routine clinical practice, before being presented with FLAGS classification via color-coded map. The accuracy of the readers with and without FLAGS assistance is measured. RESULTS: FLAGS was used by four experts (board-certified hematopathologists) and seven pathology residents on 20 FL slides. Access to FLAGS improved overall reader accuracy with the biggest improvement seen among residents. An average AUC value of 0.75 was observed which generally indicates "acceptable" diagnostic performance. CONCLUSIONS: The results of this study show that FLAGS can be useful in increasing the pathologists' accuracy in grading the tissue. To the best of our knowledge, this study measure, for the first time, the effect of computerized image analysis on pathologists' grading of follicular lymphoma. When fully developed, such systems have the potential to reduce sampling bias by examining an increased proportion of HPFs within follicle regions, as well as to reduce inter- and intra-reader variability.


Assuntos
Diagnóstico por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos , Linfoma Folicular/classificação , Gradação de Tumores/métodos , Humanos , Linfoma Folicular/patologia
16.
Lifetime Data Anal ; 21(1): 1-19, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25097158

RESUMO

In this paper we propose a threshold regression (TR) model for time to event data related to subject health using a latent Ornstein-Uhlenbeck (OU) process that fails once it hits a boundary value for the first time. Baseline covariates are incorporated into the analysis using a log-link function for the initial state of the health process. The model provides clinically meaningful covariate effects and does not require the proportional hazards assumption of the commonly used Cox model. Unlike TR models based on the Wiener process, the OU model allows increments in the health process to depend on previous values and drifts toward a state of equilibrium or homeostasis, which are present in many biological applications. We also extend our model to incorporate a cure rate for applications with improper survival functions, such as time to tumor recurrence in a cancer clinical trial. Our models are applied to overall and relapse-free survival data of melanoma patients undergoing definitive surgery.


Assuntos
Análise de Sobrevida , Ensaios Clínicos como Assunto/estatística & dados numéricos , Intervalo Livre de Doença , Humanos , Tábuas de Vida , Conceitos Matemáticos , Melanoma/mortalidade , Melanoma/cirurgia , Modelos de Riscos Proporcionais , Análise de Regressão , Processos Estocásticos , Fatores de Tempo
17.
J Magn Reson Imaging ; 39(5): 1146-52, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24123562

RESUMO

PURPOSE: To compare exercise stress cardiac magnetic resonance (cardiac MR) to echocardiography in healthy volunteers with respect to adequacy of endocardial visualization and confidence of stress study interpretation. MATERIALS AND METHODS: Twenty-eight healthy volunteers (age 28 ± 11 years, 15 males) underwent exercise stress echo and cardiac MR one week apart assigned randomly to one test first. Stress cardiac MR was performed using an MRI-compatible treadmill; stress echo was performed as per routine protocol. Cardiac MR and echo images were independently reviewed and scored for adequacy of endocardial visualization and confidence in interpretation of the stress study. RESULTS: Heart rate at the time of imaging was similar between the studies. Average time from cessation of exercise to start of imaging (21 vs. 31 s, P < 0.001) and time to acquire stress images (20 vs. 51 s, P < 0.001) was shorter for cardiac MR. The number of myocardial segments adequately visualized was significantly higher by cardiac MR at rest (99.8% vs. 96.4%, P = 0.002) and stress (99.8% vs. 94.1%, P = 0.001). The proportion of subjects in whom there was high confidence in the interpretation was higher for cardiac MR than echo (96% vs. 60%, P = 0.005). CONCLUSION: Exercise stress cardiac MR to assess peak exercise wall motion is feasible and can be performed at least as rapidly as stress echo.


Assuntos
Endocárdio/anatomia & histologia , Endocárdio/diagnóstico por imagem , Teste de Esforço , Ventrículos do Coração/anatomia & histologia , Ventrículos do Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Função Ventricular Esquerda/fisiologia , Adulto , Ecocardiografia/métodos , Endocárdio/fisiologia , Feminino , Humanos , Masculino , Projetos Piloto , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
Stat Med ; 33(7): 1162-75, 2014 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-24123309

RESUMO

Many dose-response studies collect data on correlated outcomes. For example, in developmental toxicity studies, uterine weight and presence of malformed pups are measured on the same dam. Joint modeling can result in more efficient inferences than independent models for each outcome. Most methods for joint modeling assume standard parametric response distributions. However, in toxicity studies, it is possible that response distributions vary in location and shape with dose, which may not be easily captured by standard models. To address this issue, we propose a semiparametric Bayesian joint model for a binary and continuous response. In our model, a kernel stick-breaking process prior is assigned to the distribution of a random effect shared across outcomes, which allows flexible changes in distribution shape with dose shared across outcomes. The model also includes outcome-specific fixed effects to allow different location effects. In simulation studies, we found that the proposed model provides accurate estimates of toxicological risk when the data do not satisfy assumptions of standard parametric models. We apply our method to data from a developmental toxicity study of ethylene glycol diethyl ether.


Assuntos
Teorema de Bayes , Modelos Estatísticos , Medição de Risco/métodos , Toxicologia/métodos , Animais , Simulação por Computador , Etil-Éteres/toxicidade , Etilenoglicóis/toxicidade , Feminino , Cadeias de Markov , Camundongos , Método de Monte Carlo , Tamanho do Órgão , Gravidez , Útero/patologia
19.
Nicotine Tob Res ; 16(6): 786-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24474305

RESUMO

INTRODUCTION: Smoking prevalence is 49% among Medicaid enrollees in Ohio. The objective of this pilot project was to test a comprehensive tobacco dependence treatment program targeting rural Medicaid-enrolled smokers for both physician-level and smoker-level outcomes. METHODS: Using a group-randomized trial design, intervention group physicians (n = 4) were exposed to systems-level changes in their clinics, and smokers in these clinics were offered 12 weeks of telephone cessation counseling. Control group physicians (n = 4) were given the clinician's version of the U.S. Public Health Serivce (USPHS) Clinical Practice Guideline, and smokers in these clinics were given information about the Ohio Tobacco Quitline. Physician-level and smoker-level outcomes were assessed at 1 week and 3 months, respectively. Costs per quit were estimated. RESULTS: A total of 214 Medicaid smokers were enrolled. At 1 week, there were no reported differences in rates of being asked about tobacco use (68% intervention, 58% control) or advised to quit (69% intervention, 63% control). However, 30% of intervention and 56% of control smokers reported receiving a prescription for pharmacotherapy (p < .01). At 3 months, there were no differences in quit attempts (58% intervention, 64% control), use of pharmacotherapy (34% intervention, 46% control), or abstinence (24% intervention, 16% control for self-reported abstinence; 11% intervention, 3.5% control for cotinine-confirmed abstinence). The intervention group proved more cost-effective at achieving confirmed quits ($6,800 vs. $9,700). CONCLUSIONS: We found few differences in outcomes between physicians exposed to a brief intervention and physicians who were intensively trained. Future studies should examine how tobacco dependence treatment can be further expanded in Medicaid programs.


Assuntos
Medicaid , Abandono do Hábito de Fumar/estatística & dados numéricos , Tabagismo/terapia , Adulto , Análise Custo-Benefício , Aconselhamento/economia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ohio , Médicos de Atenção Primária , Projetos Piloto , População Rural , Abandono do Hábito de Fumar/economia , Inquéritos e Questionários , Telefone , Tabagismo/economia , Estados Unidos
20.
Stat Med ; 32(1): 67-80, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22833304

RESUMO

The Hosmer-Lemeshow test is a commonly used procedure for assessing goodness of fit in logistic regression. It has, for example, been widely used for evaluation of risk-scoring models. As with any statistical test, the power increases with sample size; this can be undesirable for goodness of fit tests because in very large data sets, small departures from the proposed model will be considered significant. By considering the dependence of power on the number of groups used in the Hosmer-Lemeshow test, we show how the power may be standardized across different sample sizes in a wide range of models. We provide and confirm mathematical derivations through simulation and analysis of data on 31,713 children from the Collaborative Perinatal Project. We make recommendations on how to choose the number of groups in the Hosmer-Lemeshow test based on sample size and provide example applications of the recommendations.


Assuntos
Interpretação Estatística de Dados , Modelos Logísticos , Modelos Estatísticos , Tamanho da Amostra , Simulação por Computador , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Masculino , Gravidez , Fumar
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