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.

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).

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.

Long-Term Outcomes of Canalith Repositioning for Benign Paroxysmal Positional Vertigo: Kaplan-Meier Estimate / 대한평형의학회지

OBJECTIVE: The objective of this study is to determine the long-term recurrence rate of benign paroxysmal positional vertigo (BPPV) and the factors associated to such recurrence. METHODS: Retrospective review was performed for 295 patients diagnosed as idiopathic BPPV. After successful resolution by particle repositioning maneuver, all patients were followed up by visiting clinic or telephone. A study period was 1–56 months and average follow up period for study population after the initial treatment was 26 months. The rate of recurrence was estimated according to the method of Kaplan-Meier and compared by the log-rank test. RESULTS: Overall recurrence rate by Kaplan-Meier estimate was 50% at 30 months. Kaplan-Meier estimate suggests the effect of patient age, sex and visit of treatment sessions in initial episode on BPPV recurrence over 3 year follow-up period. Recurrent rate was significantly higher in patients aged 40 years or older (p<0.013) and in patients with three or more visit of treatment sessions (p<0.015). However, there was no significant association between recurrence rate and sex. CONCLUSION: The long-term recurrence of BPPV was associated with age above 40 years and the number of visit for treatment sessions. This finding suggests that the recurrence of BPPV may be related with aging process.

Median Survival Time of Endometrial Cancer Patients with Lymphovascular Invasion at the Hospital Universiti Sains Malaysia

Background: Endometrial cancer is the most common gynaecologic malignancy among females worldwide. The purpose of this study was to determine the median survival time of endometrial cancer patients at the Hospital Universiti Sains Malaysia (USM). Methods: A list of 121 endometrial cancer cases registered at Hospital USM between 2000 until 2011 was retrospectively reviewed. The survival time of the endometrial cancer patients was estimated by Kaplan-Meier survival analysis. Log-rank tests were performed to compare the survival of the patients based on socio-demographics and clinical presentation. Results: Only 108 patients, 87.0%, were included who were of Malay ethnicity. Previous history included menopause in 67.6% of patients and diabetes mellitus in 39.8% of patients; additionally, 63.4% of patients were nulliparous. Tumour staging was as follows: 24.5% stage I, 10.8% stage II, 26.5% stage III and 38.2% stage IV. The overall median survival time of the endometrial cancer patients was 70.20 months (95% confidence interval (CI): 51.79, 88.61). The significant factors were age, the presence of lymphovascular invasion and treatment received. Conclusion: The overall survival of endometrial cancer was low. A prospective study needs to be carried out to discover more effective and accurate tests for the early detection of endometrial cancer.

Statistical methods for comparing survival rates at a fixed time point / 中华流行病学杂志

Comparison of survival curves between two groups is an important part of disease prognosis study.Log-rank test is commonly used,but when the two curves' later intersecting opening is too large,the proportion of assumptions is not established,thus the Log-rank test is ineffective.We introduces five statistical tests to compare two survival curves at a fixed time points:classic method,logarithmic transformation,cloglog transformation,arcsine transformation and logit transformation.Through the study we found that if the overall survival curves are difficult to compare between groups tested with Log-rank test method or Two-stage test method,the fixed time point test can effectively determine whether there was significant difference in survival rate at a fixed time point.Among the five fixed time point tests,cloglog transformation could give more precise result.

Analysis of survival data in thalassemia patients in Shiraz, Iran / 한국역학회지

OBJECTIVES: The survival rate of thalassemia patients has not been conclusively established, and the factors associated with survival remain unclear. This study aimed to determine the survival rate of thalassemia among patients in southern Iran and to identify the factors associated with mortality from thalassemia. METHODS: This retrospective cohort study was conducted based on a retrospective review of the medical records of 911 beta-thalassemia patients in 2014. Data analysis was conducted using the Kaplan-Meier method and Cox regression analysis. RESULTS: Overall, 212 patients (23.3%) died, and 26.8% had thalassemia intermedia. The 20-year, 40-year, and 60-year survival rates were 85%, 63%, and 54%, respectively. Both crude and adjusted analyses found that education, marital status, ferritin levels, and comorbidities were related to mortality. CONCLUSIONS: Sociodemographic and hematological factors were found to be significantly associated with the survival rate of thalassemia. Addressing these factors may help healthcare providers and physicians to provide the best possible care and to improve the survival rate.

Supervivencia de implantes dentales entre la primera y la segunda fase quirúrgica / Survival of dental implants between the first and the second surgical phase

Fundamento: una de las principales metas en la implantología oral es lograr la cicatrización inicial, factor definitivo en la supervivencia de los implantes dentales. Objetivo: determinar la supervivencia de implantes dentales colocados en pacientes que asistieron a la Universidad Cooperativa de Colombia entre Junio y Diciembre de 2011. Método: se realizó un estudio de corte transversal, se tomó una muestra de 59 implantes dentales en 15 pacientes con el fin de analizar variables relacionadas con el maxilar, sitio anatómico, tipo de incisión, diseño, diámetro y longitud de los implantes, apariencia radiográfica y movilidad de los implantes, así como la presencia de dolor durante la evaluación de los implantes instalados. El tiempo mediano de supervivencia de los implantes se describió a través del método de Kaplan-Meier. Resultados: se evaluaron 59 implantes en 15 pacientes con edad promedio de 54 años (D.E. ± 9) de los cuales el 60 % fueron colocados en mujeres. El 50,85 % de los implantes situados se encontraron en el maxilar superior y el 49,15 % en el maxilar inferior. El 96,6 % fueron colocados en pacientes con pérdida parcial de dientes y un 3,4 % en edéntulos totales. La supervivencia de los implantes dentales para el maxilar superior fue del 96,6 % y para el maxilar inferior del 93,1 %. Conclusiones: en el presente estudio la supervivencia de los implantes dentales fue elevada con algunos fracasos que ocurrieron durante los primeros meses de cicatrización.

Background: one of the main goals in implantology is to achieve initial healing in the survival of dental implants. Objective: to determine the survival of dental implants placed in patients attending the Universidad Cooperativa de Colombia between June and December 2011. Method: in this cross-sectional study of a sample of 59 dental implants to analyze variables related to the maxilla, anatomical site, type of incision, design, length and diameter of the implants, radiographic appearance and mobility implants, as well as the presence of pain during the evaluation of the implants installed were revised. The median survival time of implants were described by Kaplan Meier. Results: a total of 59 implants in 15 patients with a mean age of 54 years (± 9) were evaluated, of which 60% were placed on women. The 50.85 % of the implants were installed in the maxilla and 49.15 % in the lower jaw. 96.6 % were placed in partially edentulous patients and 3.4 % in totally edentulous. The survival of dental implants for the upper jaw was 96.6 % and for 93.1 % of the lower jaw. Conclusions: in the present study the dental implant survival was high with some failures that occurred during the first months of healing.

Factors Associated with the Timing of First Sexual Intercourse Among College Students in Busan, Korea / 대한남성과학회지

PURPOSE: The purpose of this study was to predict when college students in Korea have their first sexual intercourse and to explore the factors associated with the timing of first sexual intercourse. MATERIALS AND METHODS: Data are collected by using self-report survey toward total 797 of male and female college students who are currently attending the college in Busan, Korea. Students were divided by four groups according to their age of timing of first sexual intercourse, <16 years, between 16 to under 19, over 19 years and non-experienced. To examine the difference of four groups, Chi-square test and ANOVA (analysis of variance) were used. For estimation of the timing of first sexual intercourse we used Kaplan-Meier estimation and for differences of each group we used log-rank test. To identify the factors associated with the timing of first sexual intercourse we used Cox proportional hazards model. RESULTS: 41.4% of college students have experienced sexual intercourse. Of four groups the early sexual intercourse group (<16 years) had high rate of cigarette smoking, alcohol drinking, drug use, open sexual attitude, and a high number of sex partner. The factors associated with the timing of first sexual intercourse among college students was identified male, open parents attitude about sex, pornography experiences, cigarette smoking, alcohol drinking. CONCLUSIONS: This study predicts the timing of first sexual intercourse among college students in Korea. Early sexual debut is an important indicator for continued risk behavior regarding reproductive health.