Infección con SARS-CoV2, antes y después de la vacunación, en funcionarios de un hospital de mediana y alta complejidad / Sars-CoV2 infection, before and after vaccination, in health care workers of a medium and high complexity hospital

Introducción: La pandemia de COVID-19 evidenció la importancia de los trabajadores esen-ciales de la salud. Objetivo: Estimar la ocurrencia de la infección por el virus Sars_CoV2 en funcionarios de un hospital, antes y después de implementación del programa de vacunación institucional y la fracción preventiva atribuible a la vacunación. Material y métodos: Estudio de cohorte histórica, teniendo como punto de inicio la fecha del primer funcionario diagnosticado con la Covid19 en el Hospital. Alrededor de mil traba-jadores fueron examinados, durante el periodo de estudio comprendido entre junio de 2020 y octubre 2021. Se utilizó el estadístico de Kaplan-Meier, para comparar la velocidad de infección y la fracción preventiva atribuible al programa de vacunación. Resultados. Hubo diferencias estadísticamente significativas en la reducción de casos según tipo de trabajo, los trabajadores asistenciales experimentaron una reducción del 58,1%, de 124 a 52 y la diferencia en la mediana de la velocidad de infección, antes y después, Log Rank = 127,4 gl = 1 p = 0,000; los administrativos 51,7% de 29 a 14, mediana log Rank = 34,4 gl = 1 p = 0,000, y los operativos 45,5% de 11 a 6, mediana Log Rank = 13,5 gl = 1 p = 0,000. La fracción atribuible preventiva entre los asistenciales fue 47,5% (37,4­54,9); 85,2% (77,7­88,9) en administrativos y una reducción no significativa de 43,6% (-20,7, 63,2) en operativos. Conclusiones: Los trabajadores asistenciales tienen un riesgo alto de contraer la infección por Sars_CoV2. Fue una acertada decisión vacunar a todos los trabajadores del hospital, el impacto es demostrable.

Introduction: The COVID-19 pandemic highlighted the importance of essential health care workers.Objective: To estimate the occurrence of Sars_CoV2 virus infection in hospital staff before and after implementation of the institutional vaccination program and the preventive fraction attributable to vaccination. Material and methods: Historical cohort study, having as starting point the date of the first employee diagnosed with Covid19 in the Hospital. About one thousand workers were exa-mined, during the study period from June 2020 to October 2021. The Kaplan-Meier statistic was used to compare the infection, rate and the preventive fraction attributable to the vac-cination program. Results: There were statistically significant differences in the reduction of cases according to type of work, with the assistential workers experiencing a reduction of 58.1%, from 124 to 52 and the difference in median infection rate, before and after, Log Rank = 127.4 gl = 1 p = 0.000; the administrative 51.7% from 29 to 14, median Log Rank = 34.4 gl = 1 p = 0.000, and the operatives 45.5% from 11 to 6, median Log Rank = 13.5 gl = 1 p = 0.000. The preventive attributable fraction among assistants was 47.5% (37.4-54.9); 85.2% (77.7-88.9) in adminis-trative and a non-significant reduction of 43.6% (-20.7, 63.2) in operatives.Conclusions: Healthcare workers are at high risk of contracting Sars_CoV2 infection. It was a wise decision to vaccinate all hospital workers, the impact is demonstrable.

Supervivencia observada en tres familias de tilapia del Nilo (Oreochromis niloticus) infectadas con Streptococcus agalactiae / Survival observed in three families of Nile tilapia (Oreochromis niloticus) infected with Streptococcus agalactiae

RESUMEN La estreptococosis es una de las principales enfermedades en los peces de agua dulce que causa altas tasas de mortalidad. El objetivo de este estudio fue evaluar la respuesta en la supervivencia a la infección por Streptococcus agalactiae en tres familias de tilapia. El experimento se llevó a cabo en el Laboratorio de Enfermedades de los Peces de la Universidad Federal de Lavras. Se utilizaron peces con un peso de 93,7 ± 5,4 g de tres familias diferentes (FA, FB y FC). Se utilizaron 36 peces en cada unidad experimental, inoculados intraperitonealmente con 107 UFC/mL de Streptococcus agalactiae por peces y un grupo control por familia con 9 peces con 1 mL de caldo BHI (Infusión Cerebro Corazón) evaluados durante 15 días. No hubo mortalidad del grupo control. Se observó la presencia de exoftalmia, coloración oscura en todo el cuerpo, letargo y dilatación abdominal antes de la muerte en las tres familias evaluadas expuestas al patógeno. El estimador no paramétrico de Kaplan-Meier se utilizó para observar las curvas de supervivencia. Durante los 15 días del desafío, el tiempo promedio de supervivencia de un individuo en las familias FA, FB y FC fue de 9,4; 6,90 y 8,14 días, respectivamente. Pruebas de Log-rank y Peto & Peto para evaluar la diferencia entre las curvas de supervivencia arrojaron que no hubo diferencias significativas entre las familias evaluadas (P=0,08 y P= 0,09), respectivamente.

ABSTRACT Streptococcosis is one of the main diseases in freshwater fish that causes high mortality rates. The objective of this study was to evaluate the survival response to Streptococcus agalactiae infection in three families of tilapia. The experiment was carried out at the Laboratory of Fish Diseases of the Federal University of Lavras. Fish weighing 93.7 ± 5.4 g from three different families (FA, FB, and FC) were used. 36 fish were used in each experimental unit, intraperitoneally inoculated with 107 CFU/mL of Streptococcus agalactiae per fish and a control group per family with 9 fish with 1 mL of BHI broth (Brain Heart Infusion) evaluated for 15 days. There was no mortality in the control group. The three evaluated families exposed to the pathogen observed the presence of exophthalmia, dark coloration throughout the body, lethargy, and abdominal dilation before death. The Kaplan-Meier nonparametric estimator was used to observe the survival curves. During the 15 days of the challenge, the average survival time of an individual in the FA, FB, and FC families was 9.4, 6.90, and 8.14 days, respectively. Log-rank and Peto & Peto test to evaluate the difference between the survival curves showed no significant differences between the assessed families (P=0.08 and P= 0.09), respectively.

Sars-CoV-2 infection rate in employees of a medium and high complexity hospital / Velocidad de la infección con Sars-CoV-2, en funcionarios en un hospital de mediana y alta complejidad

Introduction: The coronavirus disease 2019 (COVID-19) was originally identified in the city of Wuhan, China, in December 2019. Current evidence indicates that the COVID-19-causing virus is transmitted person-to-person through direct contact and droplets. Objective: To estimate Sars-CoV-2 virus infection rate in hospital employees according to their job responsibilities. Materials and methods: Retrospective cohort study to detect Sars-CoV-2 infection in hospital employees, carried out between February 2020 and October 2021. The Kaplan Meier procedure was carried out to estimate the virus infection rate based on variables such as gender, age and job description. Results: There was a difference in infection rate between young and older adult age groups (Log Rank=18.6 gl=1 p=<0.0001). A significant difference was also found between young adult and older adult groups (Log Rank=10.6 gl=1 p=0.0011). Conclusions: The older adult group showed a higher infection rate than that observed in younger age groups. These findings highlight the occupational risk of Sars-CoV-2 infection in health workers, especially in older employees. Therefore, it is necessary to maintain safety measures in order to reduce infection risks.

Introducción: La enfermedad por coronavirus 2019 se identificó originalmente en la ciudad de Wuhan, China, en diciembre de 2019. La evidencia actual indica que el virus que causa la COVID-19 se transmite de persona a persona a través del contacto directo y gotitas. Objetivo: Estimar la tasa de infección por el virus Sars-CoV-2 en empleados de hospitales según sus responsabilidades laborales. Materiales y métodos: Estudio de cohorte retrospectivo para detectar infección por Sars-CoV-2 en empleados de hospitales, realizado entre febrero 2020 y octubre 2021. Se realizó el procedimiento de Kaplan Meier para estimar la tasa de infección del virus según género, edad y descripción del trabajo. Resultados: Hubo una diferencia en la tasa de infección entre los grupos de edad de adultos jóvenes y mayores (Log Rank=18,6 gl=1 p=<0,0001). Se encontró una diferencia significativa entre grupos de adultos jóvenes y adultos mayores (Log Rank=10.6 gl=1 p=0.0011). Conclusiones: Los adultos mayores presentaron una tasa de infección superior a la observada en grupos de edades más jóvenes. Se resalta el riesgo ocupacional de infección por Sars-CoV-2 en los trabajadores de la salud, especialmente en los empleados de mayor edad. Es necesario mantener las medidas de seguridad para reducir los riesgos de infección.

Survival Analysis: Where, Why, What and How?

Durations of any event, such as duration of hospitalization, is usually found to have a highly skewed distribution and incomplete values due to dropouts and limited follow-up. The usual methods of statistical analysis are, therefore, not applicable. The method of survival analysis is a nonparametric method and is designed to overcome these problems. Survival is a generic term and is used for any time-toevent data. The entire survival pattern at different points in time is studied by the Kaplan-Meier method under certain conditions. Logrank method is used to compare survival pattern in two or more groups. Hazard is the rate of occurrence of an event per unit of time and studied by Cox method. The concept of survival and all these methods of survival analysis are briefly discussed in this short note in a non-mathematical format for medical audience.

OShnscc: a novel user-friendly online survival analysis tool for head and neck squamous cell carcinoma based on RNA expression profiles and long-term survival information / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Head and neck squamous cell carcinoma (HNSCC), as the most common type (>90%) of head and neck cancer, includes various epithelial malignancies that arise in the nasal cavity, oral cavity, pharynx, and larynx. In 2020, approximately 878 ‍ 000 new cases and 444 000 deaths linked to HNSCC occurred worldwide (Sung et al., 2021). Due to the associated frequent recurrence and metastasis, HNSCC patients have poor prognosis with a five-year survival rate of 40%-50% (Jou and Hess, 2017). Therefore, novel prognostic biomarkers need to be developed to identify high-risk HNSCC patients and improve their disease outcomes.

Perfil clínico-epidemiológico e sobrevida hospitalar dos casos de leucemia aguda em um hospital de referência em Rio Branco, Acre, 2007-2014 / Clinical epidemiological profile and survival of hospital cases of acute leukemia in a reference hospital in Rio Branco - Acre, 2007-2014

Resumo Introdução A Unidade de Assistência de Alta Complexidade em Oncologia (UNACON) permite o tratamento de leucemias agudas no Acre. Objetivo Determinar o perfil clínico-epidemiológico e a sobrevida hospitalar de leucemias agudas tratadas na UNACON/Acre entre 2007 e 2014. Método É um estudo longitudinal e retrospectivo de pacientes com leucemias agudas entre 15/06/2007 e 31/12/2014, cujos prontuários médicos forneceram dados para a análise descritiva das variáveis e posterior análise de sobrevida acumulada em 1 ano e 2 anos (método Kaplan-Meier) e comparação das curvas de sobrevida (teste de log-rank). Resultados A sobrevida para leucemias mieloides agudas (LMA) foi de 30% e 32% em 1 e 2 anos, respectivamente, com pior sobrevida para pacientes masculinos, brancos, ≥ 20 anos de idade, leucometria < 20.000 células/mm3, desidrogenase lática ≥ 600 U/dl e subtipo diferente do M3. Para leucemias linfoides agudas (LLA), a sobrevida foi de 59% e 45% em 1 e 2 anos, respectivamente, com pior sobrevida para sexo feminino, ≥ 20 anos de idade e leucometria elevada. Em pacientes abaixo de 20 anos de idade com LLA, a melhor sobrevida foi observada na faixa etária de 2 a 9 anos. Conclusão Trata-se do primeiro estudo epidemiológico de sobrevida realizado no Acre para leucemias agudas com resultados coerentes com a literatura. Contudo, novas pesquisas deverão ser realizadas.

Abstract Background The High Complexity Oncology Unit (Unidade de Assistência de Alta Complexidade em Oncologia - UNACON/Acre) allowed the treatment of acute leukemias in Acre. Objective To determine the clinical-epidemiological profile and hospital survival of acute leukemias treated at UNACON/Acre between 2007 and 2014. Method This is a longitudinal, retrospective study of patients with acute leukemias between 06/15/2007 and 12/31/2014 whose medical records provided data for descriptive analysis of the variables, and subsequent analysis of 1-year and 2-year cumulative survival (Kaplan Meier method) and comparison of survival curves (log-rank test). Results The survival for acute myeloid leukemia (AML) was 30 and 32% at 1 and 2 years, respectively, with a worse survival rate for males, white, age ≥20 years, leukometry <20,000 cells/mm3, lactic dehydrogenase ≥600 U/dl and subtype different from M3. For acute lymphoid leukemias (ALL), survival was 59 and 45% at 1 and 2 years, respectively. Female gender, age ≥20 years, and high leukometry had worse survival. For patients <20 years with ALL, better survival was observed in the age group of 2-9 years. Conclusion This is the first epidemiological study of survival in Acre for acute leukemias with results consistent with the literature. However, new studies should be performed.

Risk factors associated with mortality in patients hospitalized for coronavirus disease 2019 in Rio de Janeiro, Brazil

Abstract INTRODUCTION: Understanding the mortality-associated risk factors of coronavirus disease 2019 will impact clinical decisions. METHODS: This retrospective longitudinal study included patients hospitalized for coronavirus disease in Rio de Janeiro, Brazil. The Kaplan-Meier method and multivariate Cox regression analysis were used. RESULTS: Sequential Organ Failure Assessment score of ≥2 (hazard ratio 4.614; 95% confidence interval =2.210-9.634; p<0.001) and neutrophil/lymphocyte ratio of >5 (hazard ratio=2.616; 95% confidence interval=1.303-5.252; p=0.007) were independently associated with mortality. CONCLUSIONS: Sequential Organ Failure Assessment score and neutrophil/lymphocyte ratio on admission can identify coronavirus disease patients at increased risk of death and guide subsequent clinical decisions.

Bioinformatic analysis between epithelioid and mixed uveal melanoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the differentially expressed genes and crucial genes between epithelioid and mixed uveal melanoma(UM)based on bioinformatics analysis.<p>METHODS: Microarray datasets GSE22138 was extracted from gene expression omnibus database(GEO). The differentially expressed genes(DEGs)were screened out between epithelioid and mixed UM, and functional enrichment analysis were performed with DAVID database. STRING and cytoscape was applied to explore the protein-protein interaction(PPI)network and hub genes. Subsequently, cBioPortal was applied to explore the network of the hub genes, and GEPIA was adopted to study the survival analysis of hub genes.<p>RESULTS: Overall, 241 DEGs including 125 upregulated and 116 down regulated genes were identified. The DEGs mainly enriched in cell adhesion, response to drug and Positive regulation of endothelial cell proliferation. A total of 10 hub genes were identified. Survival analysis revealed the hub genes was associated with the prognosis of UM.<p>CONCLUSION: DEGs and hub genes identified by Bioinformatics analysis in the present study would be beneficial to understand mechanism and biological characteristics between epithelioid and mixed UM.

A Prospective Study of AKI by Using Koralkar Criteria in Hospital Born Preterm Babies

Background: Acute kidney injury (AKI) is a clinical conditionoften seen in the neonatal intensive care units. The incidenceof AKI in neonates treated at the NICU ranges from 2.4 to 56%. Many etiological factors predispose development of AKI inneonates. AKI has a significant impact on survival rates,especially in preterm infants and Neonates with AKI have veryhigh mortality rates (4.5–78 %). Our understanding of AKI inLBW newborns is mostly limited to retrospective studies. So weplanned a prospective study in preterm babies with AKIdiagnosed by Koralkar criteria.Objectives: To find proportion of preterm babies (<37 weeksof gestation) with acute kidney injury born in the hospitals andto find out demographics, co-morbidities, clinical presentation,risk factors, and outcome in preterm newborns with AKI.Materials & Methods: A Prospective study on 215 pretermbabies was conducted at Neonatal units attached to SMSMedical College, Jaipur during Feb 2015 to March 2017. Thestudy variables were analyzed using Epi-Info7 software withapplication of Mean, Proportion, Chi-square, t- test, regressionanalysis and Kaplan-Meier Survival analysis.Results and Conclusion: Out of 215 pre-term infants 36(16.7%) had AKI with maximum patients in cat.1 (11.1%). Outof 36 preterm infants with AKI 13 died and no statisticallysignificant association was found between AKI and mortalityamong preterm infants. Statistically significant association wasfound between birth weight, sepsis, HMD, MV, NEC andmortality among preterm infants. Logistic regression wasperformed to eliminate potential confounders. Our final modelincluded variables with p<0.10. After regression analysis onlybirth weight was associated with mortality among preterminfants with p=0.028. On comparing survival among pretermwith AKI and without AKI the Average Hazard Rate was moreamong preterm infants with AKI but on applying Log Rank Testno statistically significant difference was found between thesurvival probabilities of the two groups.

Aplicación de modelos paramétricos alternativos para el análisis de supervivencia de pacientes con cáncer / Application of alternative parametric models for the survival analysis of cancer patients

RESUMEN En el presente artículo se describe una metodología que permite tener un acercamiento a modelos probabilísticos alternativos para el análisis de supervivencia, con censura por la derecha, distintos a los que usualmente se estudian (distribución: exponencial, gamma, Weibull y log-normal), ya que es posible que los datos no se ajusten siempre con suficiente precisión por las distribuciones existentes. La metodología utilizada permite mayor flexibilidad de modelar observaciones extremas, ubicadas generalmente en la cola derecha de la distribución de los datos, lo cual admite que algunos eventos aún tengan la probabilidad de ocurrir, lo que no sucede con los modelos tradicionales y el estimador de Kaplan-Meier, el cual estima para los tiempos más prolongados, probabilidades de supervivencia aproximadamente iguales a cero. Para mostrar la utilidad de la propuesta metodológica, se consideró una aplicación con datos reales que relaciona tiempos de supervivencia de pacientes con cáncer de colon.

ABSTRACT This article describes a methodology that allows an approach to alternative right-censored probabilistic models for the analysis of survival, different to those usually studied (exponential, gamma, Weibull, and log-normal distribution) since it is possible that the data do not always fit with sufficient precision due to existing distributions. The methodology used allows for greater flexibility when modeling extreme observations, generally located in the right tail of data distribution, which admits that some events still have the probability of occurring, which is not the case with traditional models and the Kaplan-Meier estimator, which estimates for the longest times, survival probabilities approximately equal to zero. To show the usefulness of the methodological proposal, we considered an application with real data that relates survival times of patients with colon cancer (CC).

Drawing Guideline for JKMS Manuscript (01) Kaplan-Meier Curve and Survival Analysis

The appropriate plot effectively conveys the author's conclusions to readers. Journal of Korean Medical Science will provide a series of special articles to show you how to make consistent and excellent plots easier. In the first of this series of special articles, I will cover Kaplan-Meier curve (or Kaplan-Meier plot) and the ease tools. This plot, generated as a result of the Survival Analysis, provides a visualization of the ‘Kaplan-Meier Survival Probability Estimate’ for each group.

Serum Vitamin D and Long-term Outcomes of Benign Paroxysmal Positional Vertigo

OBJECTIVES: The purpose of the present study was to examine the effect of serum vitamin D concentrations on the long-term recurrence rates of benign paroxysmal positional vertigo (BPPV) patients. METHODS: The present study was conducted with patients diagnosed with BPPV from June 2014 to April 2016. Whether the patients' sex, age, types and locations of semicircular canals, diabetes, hypertension, hyperlipidemia, and vitamin D concentrations affect their recurrence rates was examined using Pearson chi-square tests, independent samples t-tests and Cox proportional hazards regression analyses. The effects of vitamin D concentrations on long-term recurrence rates were examined using Kaplan-Meier estimates and log-rank tests. RESULTS: The recurrence rates obtained with Kaplan-Meier estimates were 18% and 50% at 12 months and 24 months, respectively. When the patients were divided into groups with vitamin D concentrations of <10 ng/mL and ≥10 ng/mL and the recurrence rates of the groups were compared, the difference was statistically significant (P=0.040). In addition, when the patients were divided into groups with vitamin D concentrations of <15 ng/mL and ≥15 ng/mL and the recurrence rates of the groups were compared, the difference was statistically quite significant (P=0.017). In a Cox regression model, variables such as age, sex, the types and locations of semicircular canals, hypertension, diabetes, hyperlipidemia, and 25-hydroxy vitamin D did not significantly affect recurrence. CONCLUSION: The present study investigated the recurrence rates of BPPV in patients for a long time without limiting the sex, age, or locations of semicircular canals and it could be seen that serum vitamin D concentrations significantly affected the recurrence of BPPV.

Review of statistical methods for survival analysis using genomic data

Survival analysis mainly deals with the time to event, including death, onset of disease, and bankruptcy. The common characteristic of survival analysis is that it contains “censored” data, in which the time to event cannot be completely observed, but instead represents the lower bound of the time to event. Only the occurrence of either time to event or censoring time is observed. Many traditional statistical methods have been effectively used for analyzing survival data with censored observations. However, with the development of high-throughput technologies for producing “omics” data, more advanced statistical methods, such as regularization, should be required to construct the predictive survival model with high-dimensional genomic data. Furthermore, machine learning approaches have been adapted for survival analysis, to fit nonlinear and complex interaction effects between predictors, and achieve more accurate prediction of individual survival probability. Presently, since most clinicians and medical researchers can easily assess statistical programs for analyzing survival data, a review article is helpful for understanding statistical methods used in survival analysis. We review traditional survival methods and regularization methods, with various penalty functions, for the analysis of high-dimensional genomics, and describe machine learning techniques that have been adapted to survival analysis.

What Should We Consider Carefully When Performing Survival Analysis? / 임상소아혈액종양

The survival data and the survival analysis are the data and analysis methods used to study the probability of survival. The survival data consist of a period from the juncture of a start event to the juncture of the end event (occurrence event). The period is called the survival period or survival time. In this way, the method of analysing the survival time of subjects and appropriately summarizing the degree of survival is called survival analysis. To understand and analyse survival analysis methods, researchers must be aware of some concepts. Concepts to be aware of in the survival analysis include events, censored data, survival period, survival function, survival curve and so on. This review focuses on the terms and concepts used in the survival analysis. It will also cover the types of survival data that should be collected and prepared when using actual survival analysis method and how to prepare them.

Retrospective study on survival, success rate and complication of implant-supported fixed prosthesis according to the materials in the posterior area / 대한치과보철학회지

PURPOSE: The purpose of this study was to retrospectively investigate the survival and success rate of implant-supported fixed prosthesis according to the materials in the posterior area. Other purposes were to observe the complications and evaluate the factors affecting failure. MATERIALS AND METHODS: Patients who had been restored implant prosthesis in the posterior area by the same prosthodontist in the department of prosthodontics, dental hospital, Chonbuk National University, in the period from January 2011 to June 2018 were selected for the study. The patient's sex, age, material, location, type of prosthesis and complications were examined using medical records. The Kaplan-Meier method was used to analyze the survival and success rate. The Log-rank test was conducted to compare the differences between the groups. Cox proportional hazards model was used to assess the association between potential risk factors and success rate. RESULTS: A total of 364 implants were observed in 245 patients, with an average follow-up of 17.1 months. A total of 5 implant prostheses failed and were removed, and the 3 and 5 year cumulative survival rate of all implant prostheses were 97.5 and 91.0, respectively. The 3 and 5 year cumulative success rate of all implant prostheses were 61.1% and 32.9%, respectively. Material, sex, age, location and type of prosthesis did not affect success rate (P>.05). Complications occurred in the order of proximal contact loss (53 cases), retention loss (17 cases), peri-implant mucositis (12 cases), infraocclusion (4 cases) and so on. CONCLUSION: Considering a high cumulative survival rate of implant-supported fixed prostheses, regardless of the materials, implant restored in posterior area can be considered as a reliable treatment to tooth replacement. However, regular inspections and, if necessary, repairs and adjustments are very important because of the frequent occurrence of complications

Use of interval-censored survival data as an alternative to Kaplan-Meier survival curves: studies of oral lesion occurrence in liver transplants and cancer recurrence

After undergoing liver transplantation, children are susceptible to oral lesions due to immunosuppressant drugs that are needed to maintain the transplant. In this context, it is important to understand how disease characteristics and age at transplantation influence the development of these lesions. Monitoring of lesions begins after transplantation and children are usually observed by a specialist in stomatology at periodic visits. Consequently, lesion development is estimated to occur between two observed times, and this is characterized as interval-censored data. However, in clinical practice, it is common to assume the moment of observation as the time of event occurrence, thereby excluding interval-censored data. Here, we discuss the impact of excluding interval-censored mechanisms in statistical analyses by using simulation studies to consider differences in sample sizes and amplitudes between observed intervals. Then, application studies are presented which use a data set from a prospective study that was conducted to investigate oral lesions in patients after liver transplantation at the A.C.Camargo Cancer Center in Brazil between 2013 and 2016 and a data set involving recurrent ovarian cancer in patients diagnosed with high-grade serous carcinoma at the A.C.Camargo Cancer Center between 2003 and 2016 (AU)

Analysis of eight-year follow-up data of plateau workers by color doppler echocardiography / 中华劳动卫生职业病杂志

Objective@#To analyze the heart rate changes and risk factors, as a result of high altitude.@*Methods@#Retrospective analysis of echocardiographic data of plateau workers at a railway maintenance company from 2006 to 2013. The survival curve method was used to analyze the abnormal rate of the heart. Kaplan-Meier method and Cox proportional hazards regression model were used to analyze the influencing factors.@*Results@#In the first occurrence of cardiac abnormalities, the main types of abnormalities were right atrium enlargement (53.47%) , right ventricle enlargement (17.36%) , and tricuspid regurgitation (16.67%) . Cox regression analysis showed that workplace altitude and first physical examination age are two influencing factors of cardiac abnormalities, and their relative risk was 1.661 and 1.039. At high altitudes (3 600~4 000 m) , nearly 40% of workers heart has not changed. But this adaptation does not observed in the ultra-high altitudes (≥4 000 m) .@*Conclusion@#There are individual differences in human adaptability to high altitude. We should take more stringent measures of health care for older people and those who work at more than 4000m. And we should abide by the rotation system for railways that are suitable for the plateau.

Survival analysis: Part I — analysis of time-to-event / 대한마취과학회지

Length of time is a variable often encountered during data analysis. Survival analysis provides simple, intuitive results concerning time-to-event for events of interest, which are not confined to death. This review introduces methods of analyzing time-to-event. The Kaplan-Meier survival analysis, log-rank test, and Cox proportional hazards regression modeling method are described with examples of hypothetical data.

Analysis of longevity and success rate of fixed, removable, and implant prostheses treated in Korea / 대한치과보철학회지

PURPOSE: The purpose of this study is to analyze the factors affecting the longevity of failed prosthesis and the success rate of the prosthesis based on the data evaluated with the newly developed Korean Academy of Prosthodontics (KAP) criteria. MATERIALS AND METHODS: Evaluation was performed in the restored prosthesis for patients who visited the prosthodontics department of the 13 dental university hospitals and general hospitals. The status of the prosthesis was classified into four categories: Good, Fair, Bad, Worst. The success was recorded if only the category was classified in ‘good’. The mean duration of failed prostheses and the success rate through Kaplan-Meier method were analyzed. RESULTS: A total of 1,804 cases of prosthesis were evaluated: 810 cases of fixed dental prostheses (FDP), 519 cases of Removable Dental Prostheses (RDP), and 475 cases of implant prosthesis. The mean duration of failed FDP was 11.41 ± 0.30 years and the median was 10 years. The mean duration of failed RDP was 8.18 ± 0.29 years and the median was 7 years. The mean duration of failed implant prosthesis was 7.99 ± 0.30 years and the median was 7 years. The factors related to the failure were as follows: number of units, abutments, abutments treated with root canal, and plaque index in FDPs; treated and opposing dentition in RDPs; the number of implants, duration of use, and plaque index in implant prostheses. CONCLUSION: The average duration of failed prosthesis was 11.41 years for FDPs, 8.18 years for RDPs, and 7.99 years for implant prosthesis, according to the evaluation with newly developed KAP criteria.

Survival of individual teeth after non-surgical endodontic treatment / 대한구강보건학회지

OBJECTIVES: The present study aimed to estimate the survival rate of teeth after non-surgical root canal treatment and to investigate the effect of income on the tooth survival rate. METHODS: The study included 1,414.668 endodontically treated teeth from 1,193.666 persons enrolled in the National Health Insurance Service in 2002. A survival analysis of the teeth was performed using the Kaplan-Meier method. The survival rates were calculated using a follow-up period of 11 years after the root canal treatment. RESULTS: In the present study, the 11-year cumulative survival rate of teeth after non-surgical endodontic treatments was 86.90%. The survival rates of teeth tended to decrease for the posterior teeth; the maxillary teeth showed a lower survival rate than that of the mandibular teeth. The teeth with the highest survival rates were the mandibular left lateral incisor, maxillary right incisor, mandibular right lateral incisor, and maxillary left central incisor, in that order. The lowest survival rates were shown by the mandibular second molar, maxillary second molar, maxillary first molar, and mandibular first molar, in that order. The survival rate of the first molar (#16, #26, #36, #46) was higher in the low-income group than in the high-income group (P<0.001). CONCLUSIONS: This study represents the outcome pattern of root canal treatment among South Korean individuals. These study findings can be used as comparative data for clinical decision making about endodontic treatment.