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1.
Adv Exp Med Biol ; 1232: 361-367, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893432

RESUMO

Hyperspectral imaging is a promising clinical imaging modality with multiple applications in wound care, dermatology, and ophthalmology. However, with current technologies, hyperspectral imagers are relatively large and expensive devices, mainly affordable only by hospitals. Multispectral imaging can be a cost-effective alternative for hyperspectral imaging and is capable of bringing diagnostics to primary health care. Multispectral imaging uses known features of tissue chromophores to simplify imaging device design. However, to maintain design simple and cost-effective the number of illumination bands should be minimal. Thus, proper band selection is very important. The goal of the current study is to develop an analytical model for the optimization of band selection for multispectral and narrow-band imaging techniques (e.g., narrow-band microscopy). METHODS: The contrast ratio has been proposed for quantification of image quality of subsurface inhomogeneities in the skin. Based on the two-flux Kubelka-Munk model, we developed an analytical approach which links the contrast ratio with optical tissue parameters. RESULTS: We obtained an explicit analytical solution for the dependence of maximal contrast ratio on optical tissue parameters. Then, we linked the minimally observable contrast ratio (cmin) with the bit depth of the camera, d: cmin = 1/(2d-1). Based on this analysis we were able to derive an explicit expression, which links camera properties with the minimally detectable changes in optical tissue parameters (both scattering and absorption). CONCLUSIONS: The proposed analytical model can be used for rapid assessment and optimization of multispectral and narrow band imaging techniques and for estimation of the accuracy of imaging techniques. The developed model confirms the utility of the contrast ratio for tissue imaging.


Assuntos
Imagem de Banda Estreita , Pele , Humanos , Iluminação , Modelos Estatísticos , Imagem de Banda Estreita/métodos , Pele/diagnóstico por imagem
2.
Anaesthesia ; 75(1): 27-36, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31282570

RESUMO

It is unclear how best to predict peri-operative cardiovascular risk in patients with atrial fibrillation undergoing non-cardiac surgery. This study examined the accuracy of the revised cardiac risk index and three atrial fibrillation thrombo-embolic risk models for predicting 30-day cardiovascular events after non-cardiac surgery in patients with a pre-operative history of atrial fibrillation. We conducted a prospective cohort study in 28 centres from 2007 to 2013 of 40,004 patients ≥ 45 years of age undergoing inpatient non-cardiac surgery who were followed until 30 days after surgery for cardiovascular events (defined as myocardial injury, heart failure, stroke, resuscitated cardiac arrest or cardiovascular death). The 2088 patients with a pre-operative history of atrial fibrillation were at higher risk of peri-operative cardiovascular events compared with the 34,830 patients without a history of atrial fibrillation (29% vs. 13%, respectively, adjusted odds ratio 1.30 (95%CI 1.17-1.45). Compared with the revised cardiac risk index (c-index 0.60), all atrial fibrillation thrombo-embolic risk scores were significantly better at predicting peri-operative cardiovascular events: CHADS2 (c-index 0.62); CHA2 DS2 -VASc (c-index 0.63); and R2 CHADS2 (c-index 0.65), respectively. Although the three thrombo-embolic risk prediction models were significantly better than the revised cardiac risk index for prediction of peri-operative cardiovascular events, none of the four models exhibited strong discrimination metrics. There remains a need to develop a better peri-operative risk prediction model.


Assuntos
Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Modelos Estatísticos , Procedimentos Cirúrgicos Operatórios , Idoso , Fibrilação Atrial/complicações , Estudos de Coortes , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Medição de Risco , Índice de Gravidade de Doença
3.
Sci Total Environ ; 698: 134141, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505366

RESUMO

The rhizomes of Coptis chinensis Franch., Coptis deltoidea C. Y. Cheng et Hsiao and Coptis teeta Wall, are sources of renowned traditional Chinese medicines. Recently, human activities and climate change has caused degeneration of the natural habitats of these pharmacological plants. Analyzing the impact of climate change on the possible distribution of Coptis herbs is essential for their future conservation and domestication. The purpose of this study was to predict the potential distribution of these valuable plants and identify the potential effects of climate change on three Coptis species, using of species distribution modeling (SDM). In this study, we first predict the distribution size variations of the three plant species, under present and future conditions. Secondly, we carried out field sampling of these three species and analyzed the chemical composition by high performance liquid chromatography (HPLC). Results show that the predicted distributions of all three Coptis herbs were not limit to the reported regions, but also cover other potential areas. Among the environmental variables, annual precipitation range (Bio2) induced the largest impact on SDMs for C. chinensis (72.2%) and C. deltoidea (37.9%), while C. teeta was more significantly affected by isothermally (Bio3, 39.2%). When comparing the possible future distribution to the present distribution of these species, a decreasing tendency was observed in the highly suitable areas of C. chinensis and the generally suitable areas of C. teeta, indicating that the environmental changes would affect the distribution of these two species. In addition, the average alkaloid content was found to be the highest in highly suitable areas, while it was decreased in moderately and generally suitable areas, indicating that alkaloid content may be related to environmental factors. In summary, these findings improve our understanding of the ecological impact of climate on the distribution of three Coptis species.


Assuntos
Mudança Climática , Coptis , Monitoramento Ambiental , Modelos Estatísticos , China , Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa
4.
Medicine (Baltimore) ; 98(52): e18421, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31876717

RESUMO

The objective of our research was to confirm the prediction role of Grobman model for vaginal birth after cesarean (VBAC) in Chinese pregnant women. In this research, 535 pregnant who had once cesarean delivery and the least once subsequent try to a vaginal labor in Jiaxing of China were involved. The Grobman background factors and five new factors were included. Overall, in total of 456 women had successful VBAC, the success percent was 85.2%. The new background variable "maternal height" was considered as an additional predictor for VBAC. The Grobman model's area under the curve (AUC) was 0.811 (95% CI = 0.751-0.870) and the AUC of this modified model combined 2 new factors was 0.834 (95% CI = 0.781-0.886). Nevertheless, there has no markedly difference between these 2 models of the AUC. In conclusion, the Grobman model was suitable for Chinese pregnant. However, further improvements were needed to make a new predictive model of VBAC success rate for Chinese pregnant women through analyzing the clinical data of vaginal trial delivery after cesarean section.


Assuntos
Nascimento Vaginal Após Cesárea/estatística & dados numéricos , Adulto , Fatores Etários , Índice de Massa Corporal , Cesárea/estatística & dados numéricos , China/epidemiologia , Feminino , Idade Gestacional , Humanos , Modelos Logísticos , Modelos Estatísticos , Gravidez , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos
5.
N Engl J Med ; 381(22): 2183, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31774976
6.
N Engl J Med ; 381(22): 2183-2184, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31774977
9.
BMC Bioinformatics ; 20(1): 501, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31623550

RESUMO

BACKGROUND: Identifying differentially abundant features between different experimental groups is a common goal for many metabolomics and proteomics studies. However, analyzing data from mass spectrometry (MS) is difficult because the data may not be normally distributed and there is often a large fraction of zero values. Although several statistical methods have been proposed, they either require the data normality assumption or are inefficient. RESULTS: We propose a new semi-parametric differential abundance analysis (SDA) method for metabolomics and proteomics data from MS. The method considers a two-part model, a logistic regression for the zero proportion and a semi-parametric log-linear model for the possibly non-normally distributed non-zero values, to characterize data from each feature. A kernel-smoothed likelihood method is developed to estimate model coefficients and a likelihood ratio test is constructed for differential abundant analysis. The method has been implemented into an R package, SDAMS, which is available at https://www.bioconductor.org/packages/release/bioc/html/SDAMS.html . CONCLUSION: By introducing the two-part semi-parametric model, SDA is able to handle both non-normally distributed data and large fraction of zero values in a MS dataset. It also allows for adjustment of covariates. Simulations and real data analyses demonstrate that SDA outperforms existing methods.


Assuntos
Espectrometria de Massas/métodos , Metabolômica/métodos , Proteômica/métodos , Software , Modelos Estatísticos
10.
Medicine (Baltimore) ; 98(40): e17409, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31577752

RESUMO

Lower urinary tract symptoms (LUTS) have detrimental impact on health-related quality of life. This study has 2 aims: first to identify the optimum model for LUTS study and then to explore the potential associated factors of LUTS and bother LUTS with the optimum model among adult women in China.The survey was conducted in 6 regions of China between February and July 2006. A modified Chinese Bristol Female LUTS questionnaire was administered. The number of LUTS was the main outcome measure. The fitting goodness was compared to identify the optimum model with likelihood ratio test statistics. Zero-inflated negative binomial (ZINB) model was used to explore the potential associated factors of LUTS and bother LUTS.Of all 18,992 respondents, 55.5% of respondents reported one (any LUTS) or more LUTS (mixed LUTS) and 36.5% of respondents reported one or more bother LUTS. With the largest log likelihood and smallest AIC and BIC, ZINB model showed the best goodness of fit. In the ZINB model, we identified multiple associated factors for any LUTS and mixed LUTS; older age (ß≥0.2), overweight [ß = 0.059, 95%CI (0.016∼0.102)], obese [ß = 0.143, 95%CI (0.087∼0.198)], postmenopausal status [ß = 0.099, 95%CI (0.023∼0.175)], prolonged labor [ß = 0.188, 95%CI (0.104∼0.272)], constipation [ß = 0.309, 95%CI (0.262∼0.357)], coexisting pelvic organ prolapse (POP) [ß = 0.348, 95%CI (0.224∼0.473)], diabetes (ß = 0.178, 95%CI (0.100∼0.257), hypertension [ß = 0.092, 95%CI (0.041∼0.143)], smoking (ß = 0.192, 95%CI (0.127∼0.258) and alcohol consumption [ß = 0.063, 95%CI (0.001∼0.126)] increased the odds of mixed LUTS. We identified multiple associated factors for bother LUTS and mixed LUTS; older age (ß ≥ 0.1), prolonged labor [ß = 0.153, 95%CI (0.031∼0.275)], constipation [ß = 0.359, 95%CI (0.292∼0.426)] coexisting POP (ß = 0.212, [95%CI (0.031∼0.393)], diabetes [ß = 0.154, 95%CI (0.030∼0.278)], and smoking [ß = 0.169, 95%CI (0.076∼0.262)] increased the odds of bother mixed LUTS.ZINB model was the optimum model to explore the potential associated factors of LUTS. Older age, coexisting POP and constipation were both closely related to any and bother LUTS, also the severity of LUTS. Compared to nulliparity, single or multiple deliveries and women who had perineal laceration had nothing to do with the severity of LUTS.


Assuntos
Sintomas do Trato Urinário Inferior/epidemiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Grupo com Ancestrais do Continente Asiático , China/epidemiologia , Comorbidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Pessoa de Meia-Idade , Modelos Estatísticos , Prevalência , Qualidade de Vida , Fatores de Risco , Índice de Gravidade de Doença , Adulto Jovem
11.
BMJ ; 367: l5383, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578177

RESUMO

OBJECTIVE: To estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk. DESIGN: Microsimulation modelling study using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon). SETTING: A parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures. POPULATION: Norwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%). COMPARISONS: Four screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence. MAIN OUTCOME MEASURES: Colorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach. RESULTS: Over 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates. CONCLUSIONS: Over a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.


Assuntos
Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer/normas , Programas de Rastreamento/normas , Modelos Estatísticos , Idoso , Colonoscopia/efeitos adversos , Colonoscopia/normas , Colonoscopia/estatística & dados numéricos , Neoplasias Colorretais/epidemiologia , Detecção Precoce de Câncer/métodos , Detecção Precoce de Câncer/estatística & dados numéricos , Feminino , Seguimentos , Humanos , Incidência , Masculino , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Noruega/epidemiologia , Sangue Oculto , Guias de Prática Clínica como Assunto , Sigmoidoscopia/efeitos adversos , Sigmoidoscopia/normas , Sigmoidoscopia/estatística & dados numéricos , Análise de Sobrevida
12.
Health Qual Life Outcomes ; 17(1): 153, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615531

RESUMO

BACKGROUND: The Functional Assessment of Cancer Therapy-Breast (FACT-B) is the most commonly used scale for assessing quality of life in patients with breast cancer. The lack of preference-based measures limits the cost-utility of breast cancer in China. The goal of this study was to explore whether a mapping function can be established from the FACT-B to the EQ-5D-5 L when the EQ-5D health-utility index is not available. METHODS: A cross-sectional survey of adults with breast cancer was conducted in China. All patients included in the study completed the EQ-5D-5 L and the disease-specific FACT-B questionnaire, and demographic and clinical data were also collected. The Chinese tariff value was used to calculate the EQ-5D-5 L utility scores. Five models were evaluated using three different modelling approaches: the ordinary least squares (OLS) model, the Tobit model and the two-part model (TPM). Total scores, domain scores, squared terms and interaction terms were introduced into models. The goodness of fit, signs of the estimated coefficients, and normality of prediction errors of the model were also assessed. The normality of the prediction error is determined by calculating the root mean squared error (RMSE), the mean absolute deviation (MAD), and the mean absolute error (MAE). Akaike information criteria (AIC) and Bayes information criteria (BIC) were also used to assess models and predictive performances. The OLS model was followed by simple linear equating to avoid regression to the mean. RESULTS: The performance of the models was improved after the introduction of the squared terms and the interaction terms. The OLS model, including the squared terms and the interaction terms, performed best for mapping the EQ-5D-5 L. The explanatory power of the OLS model was 70.0%. The AIC and BIC of this model were the smallest (AIC = -705.106, BIC = -643.601). The RMSE, MAD and MAE of the OLS model, Tobit model and TPM were similar. The MAE values of the 5-fold cross-validation of the multiple models in this study were 0.07155~0.08509; meanwhile, the MAE of the TPM was the smallest, followed by that of the OLS model. The OLS regression proved to be the most accurate for the mean, and linearly equated scores were much closer to observed scores. CONCLUSIONS: This study establishes a mapping algorithm based on the Chinese population to estimate the EQ-5D-5 L index of the FACT-B and confirms that OLS models have higher explanatory power and that TPMs have lower prediction error. Given the accuracy of the mean prediction and the simplicity of the model, we recommend using the OLS model. The algorithm can be used to calculate EQ-5D scores when EQ-5D data are not directly collected in a study.


Assuntos
Neoplasias da Mama/psicologia , Modelos Estatísticos , Qualidade de Vida , Adulto , Algoritmos , Teorema de Bayes , China , Estudos Transversais , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
14.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(10): 1304-1309, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31658535

RESUMO

Observational comparative effectiveness studies have been widely conducted to provide evidence on additional effectiveness and to support randomized controlled findings in research. Although this type of study becomes more important over time, challenges related to the common biases which stemmed from confounders, are difficult to control. This manuscript summarizes some statistical methods used on adjusting measured confounders that often noticed in research, regarding the observational comparative effectiveness. Useful traditional methods would include stratified analysis, paired analysis, covariate model and multivariable model, etc.. Unconventional adjustment approaches such as propensity score and disease risk score methods may also be used in studies, for matching, stratification and adjustment. A good study design should be able to control confounders. The limitations of all the post hoc statistical adjustment methods should also be fully understood before being appropriately applied in practical events.


Assuntos
Modelos Estatísticos , Estudos Observacionais como Assunto , Projetos de Pesquisa , Viés , Pontuação de Propensão
16.
Prensa méd. argent ; 105(9 especial): 644-651, oct 2019. fig
Artigo em Inglês | LILACS, BINACIS | ID: biblio-1046879

RESUMO

The article introduces the findings of the analysis of the existing approaches to the development of mathematical models of acoustic heart phenomena. The analysis of mathematical methods that can be used to model heart sounds has been performed with the use of reference signals from the 3M Open Library (Littmann Library) and a set of signals obtained by the authors during their previous scientific efforts. The analysis findings have allowed revealing the approaches and methods that are most suitable for developing the mathematical models of human phonocardiograms (normal and pathological) for further research efforts meant to develop methods to single out heart beats against the high level of interference and creating intervalograms to characterize the heart rate at the current moments of time. In addition to the generation of model phonocardiograms, the article reviews the methods to analyze model and real-life phonocardiograms with the assessment of an input from random and deterministic components.


Assuntos
Humanos , Fonocardiografia/instrumentação , Análise Espectral , Acústica , Modelos Estatísticos , Determinação da Frequência Cardíaca/métodos , Coração/fisiologia
17.
J Surg Oncol ; 120(7): 1177-1183, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31562830

RESUMO

BACKGROUND: Immediate breast reconstruction has many advantages but is associated with higher complication rates than delayed reconstruction. Complications can delay the delivery of adjuvant cancer treatments. This study aimed to develop and validate a risk stratification model for the prediction of perioperative complications in immediate microvascular breast reconstruction. METHODS: The association between patient and treatment variables and perioperative complications was evaluated in a retrospective cohort of 351 women undergoing immediate breast reconstruction using free deep inferior epigastric artery perforator flaps. Multivariable logistic regression was used to determine the strength of association and weighted scores were assigned. Using cumulative risk scores, patients were stratified into low, intermediate, and high-risk groups. The model was then validated in a prospective cohort of 100 consecutive patients. RESULTS: Obesity, smoking, prior radiation, and comorbidities were important predictors and incorporated into the risk model. Complications occurred in 23.5% of low-risk (95% confidence interval [CI] = 17.7-29.2), 38.4% of intermediate-risk (95% CI = 29.2-47.5) and 53.9% of high-risk (95% CI = 33.3-74.4) patients. Validation confirmed a linear relationship between the risk stratification categories and complications in a model with good predictive power (c-statistic = 0.7, 95% CI = 0.6-0.8). CONCLUSION: A simple risk score, based on known preoperative variables, provides accurate risk stratification for patients considering immediate microvascular breast reconstruction.


Assuntos
Neoplasias da Mama/cirurgia , Mamoplastia/efeitos adversos , Modelos Estatísticos , Complicações Pós-Operatórias/etiologia , Medição de Risco/métodos , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos
18.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(8): 1010-1017, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31484271

RESUMO

In recent years, with the improvement of various surveillance network, surveillance system has become an important data source for ecological study. Different data types, including cross-sectional data, time series data and panel data, containing abundant information involving exposure, outcome and confoundings. Gradually, some new statistical methods have been developed or improved for the special structural characteristics of surveillance data. In this paper, we summarized the principles of these models, preconditions, as well as their advantages and limitations.


Assuntos
Ecologia , Monitoramento Epidemiológico , Modelos Estatísticos , Vigilância da População , Estudos Transversais , Saúde Ambiental , Humanos , Projetos de Pesquisa
19.
Accid Anal Prev ; 132: 105276, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31525649

RESUMO

Traffic safety analysis at the macroscopic level usually relies on previously defined areal traffic analysis zones (TAZs) that are used as the units of investigation. Hence, statistical inference is made on the basis of such units, implying that the consideration of a certain TAZ configuration may influence the results and conclusions achieved. Regarding this, the modifiable areal unit problem (MAUP) is a well-known issue in the field of spatial statistics, which refers to the effects that arise in statistical properties and estimations when there is a change in areal units of analysis. In this paper, the consequences of MAUP have been investigated through a dataset of traffic crashes that occurred in Valencia within the years 2014 and 2015 and two common statistical models: a conditional autoregressive model and a geographically weighted regression. In the absence of an established TAZ scheme for the city, four classes of basic spatial units (BSUs) were considered: census tracts, hexagonal units and two types with construction based on the structure of main roads and intersections of the city. Each of these BSU types was specified at different levels of spatial aggregation. The main research objective was to investigate the final effects that changes in BSU type and scale have on model parameter estimations, but also the specific alterations that MAUP causes to data in terms of the distributional characteristics of the response, multicollinearity among the covariates and covariates' spatial autocorrelation. The results showed the presence and severity of MAUP for the dataset and area that were analysed. Although effects from scale variations were more moderate, changing the BSU type affected the results severely. The joint use of hexagonal units and a conditional autoregressive model achieved the best performance among all the possibilities explored, but the choice of a proper BSU unit should rely on more factors. Despite MAUP effects, educational centres showed a consistent (and negative) association with traffic crashes, a fact possibly related to their distribution across the whole city. Other covariates revealed a positive correlation with crash counts, but these findings were more uncertain given the discrepancies found at different scales and zonings.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Análise Espacial , Acidentes de Trânsito/prevenção & controle , Planejamento de Cidades , Humanos , Modelos Estatísticos , Segurança , Espanha
20.
Medicine (Baltimore) ; 98(37): e17165, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31517868

RESUMO

A thyroid cancer ultrasonography screening for all residents 18 years old or younger living in the Fukushima prefecture started in October 2011 to investigate the possible effect of the radiological contamination after the Fukushima Daiichi Nuclear Power Plant accidents as of March 12 to 15, 2011. Thyroid cancer in 184 cases was reported by February 2017. The question arises to which extent those cancer cases are a biological consequence of the radiation exposure or an artefactual result of the intense screening of a large population.Experiences with the Chernobyl accident suggest that the external dose may be considered a valid surrogate for the internal dose of the thyroid gland. We, therefore, calculated the average external effective dose-rate (µSv/h) for the 59 municipalities of the Fukushima prefecture based on published data of air and soil radiation. We further determined the municipality-specific absolute numbers of thyroid cancers found by each of the two screening rounds in the corresponding municipality-specific exposed person-time observed. A possible association between the radiation exposure and the thyroid cancer detection rate was analyzed with Poisson regression assuming Poisson distributed thyroid cancer cases in the exposed person-time observed per municipality.The target populations consisted of 367,674 and 381,286 children and adolescents for the 1st and the 2nd screening rounds, respectively. In the 1st screening, 300,476 persons participated and 270,489 in the 2nd round. From October 2011 to March 2016, a total of 184 cancer cases were found in 1,079,786 person-years counted from the onset of the exposure to the corresponding examination periods in the municipalities. A significant association between the external effective dose-rate and the thyroid cancer detection rate exists: detection rate ratio (DRR) per µSv/h 1.065 (1.013, 1.119). Restricting the analysis to the 53 municipalities that received less than 2 µSv/h, and which represent 176 of the total 184 cancer cases, the association appears to be considerably stronger: DRR per µSv/h 1.555 (1.096, 2.206).The average radiation dose-rates in the 59 municipalities of the Fukushima prefecture in June 2011 and the corresponding thyroid cancer detection rates in the period October 2011 to March 2016 show statistically significant relationships.


Assuntos
Acidente Nuclear de Fukushima , Neoplasias Induzidas por Radiação/epidemiologia , Doses de Radiação , Neoplasias da Glândula Tireoide/epidemiologia , Adolescente , Criança , Pré-Escolar , Relação Dose-Resposta à Radiação , Detecção Precoce de Câncer , Geografia Médica , Humanos , Incidência , Lactente , Recém-Nascido , Japão/epidemiologia , Modelos Estatísticos , Neoplasias Induzidas por Radiação/diagnóstico por imagem , Prevalência , Exposição à Radiação/efeitos adversos , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/efeitos da radiação , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia
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