Final efficacy analysis, interim safety analysis, and immunogenicity of a single dose of recombinant novel coronavirus vaccine (adenovirus type 5 vector) in adults 18 years and older: an international, multicentre, randomised, double-blinded, placebo-controlled phase 3 trial.

BACKGROUND: The Ad5-nCoV vaccine is a single-dose adenovirus type 5 (Ad5) vectored vaccine expressing the SARS-CoV-2 spike protein that was well-tolerated and immunogenic in phase 1 and 2 studies. In this study, we report results on the final efficacy and interim safety analyses of the phase 3 trial. METHODS: This double-blind, randomised, international, placebo-controlled, endpoint-case driven, phase 3, clinical trial enrolled adults aged 18 years older at study centres in Argentina, Chile, Mexico, Pakistan, and Russia. Participants were eligible for the study if they had no unstable or severe underlying medical or psychiatric conditions; had no history of a laboratory-confirmed SARS-CoV-2 infection; were not pregnant or breastfeeding; and had no previous receipt of an adenovirus-vectored, coronavirus, or SARS-CoV-2 vaccine. After informed consent was obtained, 25 mL of whole blood was withdrawn from all eligible participants who were randomised in a 1:1 ratio to receive a single intramuscular dose of 0·5 mL placebo or a 0·5 mL dose of 5 × 1010 viral particle (vp)/mL Ad5-nCoV vaccine; study staff and participants were blinded to treatment allocation. All participants were contacted weekly by email, telephone, or text message to self-report any symptoms of COVID-19 illness, and laboratory testing for SARS-CoV-2 was done for all participants with any symptoms. The primary efficacy objective evaluated Ad5-nCoV in preventing symptomatic, PCR-confirmed COVID-19 infection occurring at least 28 days after vaccination in all participants who were at least 28 days postvaccination on Jan 15, 2021. The primary safety objective evaluated the incidence of any serious adverse events or medically attended adverse events postvaccination in all participants who received a study injection. This trial is closed for enrolment and is registered with ClinicalTrials.gov (NCT04526990). FINDINGS: Study enrolment began on Sept 22, 2020, in Pakistan, Nov 6, 2020, in Mexico, Dec 2, 2020, in Russia and Chile, and Dec 17, 2020, in Argentina; 150 endpoint cases were reached on Jan 15, 2021, triggering the final primary efficacy analysis. One dose of Ad5-nCoV showed a 57·5% (95% CI 39·7-70·0, p=0·0026) efficacy against symptomatic, PCR-confirmed, COVID-19 infection at 28 days or more postvaccination (21 250 participants; 45 days median duration of follow-up [IQR 36-58]). In the primary safety analysis undertaken at the time of the efficacy analysis (36 717 participants), there was no significant difference in the incidence of serious adverse events (14 [0·1%] of 18 363 Ad5-nCoV recipients and 10 [0·1%] of 18 354 placebo recipients, p=0·54) or medically attended adverse events (442 [2·4%] of 18 363 Ad5-nCoV recipients and 411 [2·2%] of 18 354 placebo recipients, p=0·30) between the Ad5-nCoV or placebo groups, or any serious adverse events considered related to the study product (none in both Ad5-nCoV and placebo recipients). In the extended safety cohort, 1004 (63·5%) of 1582 of Ad5-nCoV recipients and 729 (46·4%) of 1572 placebo recipients reported a solicited systemic adverse event (p<0·0001), of which headache was the most common (699 [44%] of Ad5-nCoV recipients and 481 [30·6%] of placebo recipients; p<0·0001). 971 (61·3%) of 1584 Ad5-nCoV recipients and 314 (20·0%) of 1573 placebo recipients reported an injection-site adverse event (p<0·0001), of which pain at the injection site was the most frequent; reported by 939 (59%) Ad5-nCoV recipients and 303 (19%) placebo recipients. INTERPRETATION: One dose of Ad5-nCoV is efficacious and safe in healthy adults aged 18 years and older. FUNDING: CanSino Biologics and the Beijing Institute of Biotechnology.

Proportion of fever attributable to malaria in Colombia: potential indicators for monitoring progress towards malaria elimination / Proporción de fiebre atribuible a malaria en Colombia: indicadores potenciales para el seguimiento hacia la eliminación

ABSTRACT Objective Identify and characterize indicators to assess progress in terms of control and monitoring of malaria in endemic areas of Colombia and compare malaria elimination findings with those of countries in the same region. Methods Cross-sectional surveys were carried out in 2011 and 2014 in malaria endemic areas in Colombia, Pacific and Caribbean regions. A socio-demographic and a clinical questionnaire were applied to each participant; likewise, written and informed consents were obtained. Capillary blood samples were taken and examined through microscopic tests and rapid diagnostic test. A narrative systematic review was conducted to correlate malaria elimination in Colombia and in countries of the Amazon Region. Results The sample consisted of 548 participants from the departments of Córdoba and Nariño, Colombia. The proportion of positive malaria cases was 3 % (17/548), in which the prevalence of malaria mixed infections was 47 % (8/17). Regarding fever, temperature over 38.0o C, its prevalence was 2.7 % (15/548). Only two febrile patients tested positive for the disease. Prevalence of asymptomatic malaria cases among all positive cases was 88 %. Conclusion Asymptomatic malaria cases, mixed infections and self-medication are the challenges that malaria control and elimination programs face. It is important to note that studies on subclinical malaria in the region are scarce. Endemic areas with dense populations and experiencing an increase in immigration levels are more vulnerable to malaria reemergence. Imported malaria cases impact the basic reproduction rate (Ro). Funding resources availability has impact on the sustainability of public health actions and the elimination of malaria in South America.(AU)

RESUMEN Objetivo Identificar y caracterizar indicadores de evaluación del progreso en el control de la malaria en regiones endémicas de Colombia y contrastar los hallazgos de eliminación con países de la misma región. Métodos Se realizaron cortes transversal en 2011 y 2014, en regiones endémicas para malaria de la Costa Pacífica y del Caribe de Colombia. Se obtuvo consentimiento informado y se aplicó una encuesta socio-demográfica y clínica a cada voluntario. La punción capilar se utilizó para examen microscópico y pruebas de diagnóstico rápido. La revisión narrativa y sistemática permitió comparar el estado de eliminación de malaria en Colombia y los países de la Amazonía. Resultados Un total de 548 voluntarios fueron estudiados en Córdoba y Nariño. La proporción de casos positivos de malaria fue 3 % (17/548). Las infecciones mixtas de malaria se presentaron en un 47 % (8/17). La prevalencia de fiebre, temperatura mayor o igual a 38oC, fue 2.7 % (15/548). Dos pacientes febriles fueron positivos para malaria. La prevalencia de casos asintomáticos se presentó en 88 %. Conclusión Los casos de malaria asintomática, infecciones mixtas y la automedicación constituyen un reto para los programas de control y eliminación. Estudios sobre malaria subclínica y eliminación son limitados en la región. Regiones endémicas con alta densidad poblacional y aumento en los niveles de migración incrementan la vulnerabilidad. Los casos importados afectan la reducción de la tasa reproductiva básica (Ro) por debajo de 1. El recurso financiero insuficiente afecta la sostenibilidad de las acciones de salud pública y la eliminación de malaria en las Américas.(AU)

Proportion of fever attributable to malaria in Colombia: Potential indicators for monitoring progress towards malaria elimination.

OBJECTIVE: Identify and characterize indicators to assess progress in terms of control and monitoring of malaria in endemic areas of Colombia and compare malaria elimination findings with those of countries in the same region. METHODS: Cross-sectional surveys were carried out in 2011 and 2014 in malaria endemic areas in Colombia, Pacific and Caribbean regions. A socio-demographic and a clinical questionnaire were applied to each participant; likewise, written and informed consents were obtained. Capillary blood samples were taken and examined through microscopic tests and rapid diagnostic test. A narrative systematic review was conducted to correlate malaria elimination in Colombia and in countries of the Amazon Region. RESULTS: The sample consisted of 548 participants from the departments of Córdoba and Nariño, Colombia. The proportion of positive malaria cases was 3 % (17/548), in which the prevalence of malaria mixed infections was 47 % (8/17). Regarding fever, temperature over 38.0o C, its prevalence was 2.7 % (15/548). Only two febrile patients tested positive for the disease. Prevalence of asymptomatic malaria cases among all positive cases was 88 %. CONCLUSION: Asymptomatic malaria cases, mixed infections and self-medication are the challenges that malaria control and elimination programs face. It is important to note that studies on subclinical malaria in the region are scarce. Endemic areas with dense populations and experiencing an increase in immigration levels are more vulnerable to malaria reemergence. Imported malaria cases impact the basic reproduction rate (Ro). Funding resources availability has impact on the sustainability of public health actions and the elimination of malaria in South America.

Discapacidad laboral por dolor lumbar: estudio caso control en Santiago de Chile / Work disability for lower back pain: case control study in Santiago

ANTECEDENTES. La discapacidad laboral por dolor lumbar causa ausencia laboral y gastos económicos. Se ha responsabilizado su presencia a condiciones del entorno laboral y a la manipulación manual de cargas (MMC). Se evaluó la asociación entre niveles de exposición laboral a MMC y presencia de discapacidad en trabajadores protegidos por ley laboral en Santiago de Chile. MATERIAL Y MÉTODO. Estudio Caso Control. Exposición y covariables de interés fueron medidas en puesto de trabajo. Los análisis incluyeron Modelos de Regresión Logística Múltiple. RESULTADOS. La exposición a MMC moderada muestra OR: 1,62 (IC95%:0,61-4,33), la exposición a MMC alta y muy alta muestra OR de 2,75 (IC95%:1,08-6,95). DISCUSIÓN. Existe una importante magnitud y gradiente de asociación entre MMC y discapacidad. Variables psicosociales, organizacionales e individuales también explican el fenómeno. Se sugiere rediseñar las estrategias nacionales para prevenir riesgos laborales relacionados con discapacidad por dolor lumbar.

BACKGROUND: Work disability due to low back pain causes lost productivity and economic expense. It has been blamed on the working environment and the manual handling of loads (MHL). The link between levels of work exposure to MHL and the disability of workers protected by labor law was evaluated in Santiago, Chile. MATERIALS AND METHODS: Case-control study. Exposure and study co-variables were measured in the workplace. The analyses included multiple logistic regression models. RESULT AND DISCUSSION: Exposure to moderate MHL shows an OR: 1.62 (95% CI: 0.61-4.33), high and very high exposure to MHL shows an OR of 2.75 (95% CI: 1.08-6.95), controlled by psychosocial, organizational and individual aspects. There is a significant magnitude and gradient of association between MHL and disability. Psychosocial, organizational and individual variables also explain the phenomenon. It is suggested that national strategies be redesigned to prevent the occupational risks related to disability due to low back pain.

[Diagnostic accuracy study comparing total alkaline phosphatase with intact parathyroid hormone 1-84 for the diagnosis of high turnover renal osteodystrophy in chronic renal failure on hemodialysis]. / Estudio de exactitud diagnóstica que compara fosfatasa alcalina total con paratohormona intacta 1-84 para el diagnóstico de osteodistrofia renal de alto recambio en la insuficiencia renal crónica en hemodiálisis.

INTRODUCTION: High turnover renal osteodystrophy (HTRO) is a highly prevalent complication in patients with chronic kidney disease and mineral bone disease (CKD-MBD), causing pain and significant fracture-associated morbidity and mortality. The diagnostic gold standard test is bone biopsy but there are other, more widely available screening tests such as 1-84 intact parathormone (1-84 iPTH) and nonspecific markers such as total alkaline phosphatase (tALP). PURPOSE: To determine the diagnostic value (ROC curve, predictive values and likelihood ratios) of 1-84 iPTH and tALP for HTRO screening. METHODS: A diagnostic accuracy study was performed on a sample of CKD-MDB patients, grouping them according to bone biopsy results and analyzing the results of the diagnostic tests as descriptive variables. RESULTS: The study group comprised 188 patients with CKD-MDB, 36 of which had biopsy-confirmed HTRO (19.15%). The average age was 50.2 years in the biopsy group, and 53.4 years in the non-biopsy group (p=0.2385), most were male (63.8%) and diabetic (80.5%). The mean time in dialysis was 5.02 years in the biopsy group, and 2.61 years for the non-biopsy group (p<0.001). The mean Kt/V was 1.44 in the biopsy group, and 1.40 in the non-biopsy group (p=0.5354). The mean tALP was 398.02 IU/L in the group with HTRO versus 141.76 IU/L in the group without HTRO (p<0.001). The best cut-off value for tALP was 300-350 IU/L with a near 80% post-test probability, but also with a 15-20% probability for HTRO if the test is negative. The mean 1-84 iPTH was 1248.01 pg/ml in the group with HTRO versus 350.76 pg/ml in the group without HTRO (p<0.001). The 1-84 iPTH cut-off reference value of 300 pg/ml was associated with a post-test probability of 30% for HTRO diagnosis and had a lower overall performance. The best cut-off value for iPTH 1-84 was 600 pg/ml with a post-test probability for HTRO of 70% if positive and less than 5% if the test results are negative. DISCUSSION: Both markers show good correlation with bone biopsy findings. tALP elevation detects presence of HTRO in selected patients but does not rule it out. tALP does not perform as well as 1-84 iPTH as a screening test for HTRO.

INTRODUCCIÓN: La osteodistrofia renal de alto recambio es una complicación altamente prevalente en pacientes con insuficiencia renal crónica y desorden mineral óseo, determinando dolor importante y morbimortalidad importante asociada a fracturas. El gold estándar para su diagnóstico es mediante biopsia ósea. Sin embargo, su pesquisa es mediante la elevación de paratohormona intacta 1-84 (iPTH 1-84) y otros marcadores más inespecíficos como fosfatasa alcalina total (FAT). OBJETIVOS: Determinar las propiedades diagnósticas (curva ROC, valores predictivos y likelihood ratios) de paratohormona intacta 1-84 y fosfatasa alcalina total para la sospecha de osteodistrofia renal de alto recambio. MÉTODOS: Estudio de exactitud diagnóstica tomando muestra de pacientes con insuficiencia renal crónica y desorden mineral óseo, clasificándolos según resultado de biopsia ósea y evaluando resultados de test diagnóstico señalados así como variables descriptivas de interés. RESULTADOS: De los 188 pacientes con insuficiencia renal crónica y desorden mineral óseo, 36 presentaron osteodistrofia renal de alto recambio confirmada por biopsia (19,15%). La edad promedio fue de 50,2 años en el grupo con biopsia y 53,4 en el grupo sin biopsia (p=0,2385); la mayoría fueron hombres (63,8%) y diabéticos 80,5%. El tiempo promedio en diálisis fue de 5,02 años para el grupo con biopsia y 2,61 para el grupo sin biopsia (p<0,001). Kt/V promedio 1,44 en el grupo con biopsia y 1, 40 en el grupo sin biopsia (p=0,5354). Fosfatasa alcalina total promedio 398,02 UI/L en grupo con osteodistrofia renal de alto recambio versus 141,76 UI/L en grupo sin osteodistrofia renal de alto recambio (p<0,001). El mejor valor de corte para fosfatasa alcalina total fue de ≥ 300 - 350 UI/L, determinando probabilidad post test de osteodistrofia renal de alto recambio cercana a 80% con test positivo y de 15 a 20% en caso de resultado negativo. La paratohormona intacta 1-84 promedio fue 1248,01 pg/ml en grupo con osteodistrofia renal de alto recambio versus 350,76 pg/ml en grupo sin osteodistrofia renal de alto recambio (p<0,001). El valor de corte de referencia para paratohormona intacta 1-84 ≥ 300 pg/ml se asoció a una probabilidad post test de osteodistrofia renal de alto recambio de 30% y mal rendimiento en general. El mejor valor de corte fue de ≥ 600 pg/ml con probabilidad post test de osteodistrofia renal de alto recambio del 70% con test positivo y menor a 5% con test negativo. CONCLUSIONES: Ambos marcadores estudiados muestran correlación con los hallazgos de biopsias óseas. La elevación de fosfatasa alcalina total detecta presencia de osteodistrofia renal de alto recambio en pacientes seleccionados, pero no la descarta. En rendimiento es inferior a la paratohormona intacta 1-84 como test de tamizaje.

[How many subjects do I need to power my study?]. / ¿Cuántos sujetos necesito para mi estudio?

The article presents a tool that helps answer the question “How many subjects do I need to power my study? We show how to determine sample size in observational epidemiological studies and provide examples of application using the statistical package Epidat, which is a shareware program developed under the auspices of the Pan American Health Organization, the Galician Board of Health and the University CES of Colombia. Examples of calculation of sample size for prevalence studies (cross-sectional), case-control studies and cohort studies are given.

El artículo presenta una herramienta metodológica que ayuda a responder la pregunta ¿Cuántos sujetos necesito para mi estudio? Se presenta cómo determinar tamaño de muestra en estudios epidemiológicos observacionales dando ejemplos de aplicación usando el paquete estadístico Epidat de distribución libre elaborado bajo el auspicio de la Organización Panamericana de la Salud, la Junta de Salud de Galicia y la Universidad CES de Colombia. Se dan ejemplos de cálculo de tamaño de muestra para estudios de prevalencia (corte transversal), para estudios de casos y controles y para estudios de cohortes.

Production of IL-10, TNF and IL-12 by peripheral blood mononuclear cells in Mexican workers exposed to a mixture of benzene-toluene-xylene.

BACKGROUND AND AIMS: Occupational exposure to low-level benzene and the joint action of toluene-xylene probably cause effects on circulating monocytes immune response. We undertook this study to determine relationship between occupational exposure to benzene-toluene-xylene mixture (BTX) and IL-10, TNF and IL-12 production by peripheral blood mononuclear cells. METHODS: Exposure was estimated in 54 workers from a paint company in Mexico City through BTX accumulated potential dose (BTX-APD). Two exposure groups were formed: high and low BTX-APD established with a cutoff point at ≥1.0 of BTX-APD, as a function of the geometric mean of the estimator's value distribution and the higher agreement between BTX-APD ≥1.0 and the areas referred as using (or not) organic solvents in the work process. IL-10, TNF and IL-12 concentrations were measured with ELISA. Through multiple linear regression models, the production of each of the proposed cytokines and of the whole set was assessed. RESULTS: Workers with high BTX-APD showed a significant reduction in TNF production (ß = -1,196.0 pg/mL; p = 0.01); a reduction for IL-10 (ß = -520.3; p = 0.13) and IL-12 (ß = -843.3; p = 0.09) was also observed, although without statistical significance. CONCLUSIONS: TNF production assessed in workers with a high BTX-APD is lower than in those with a low BTX-APD, but not in IL-10 and IL-12 production.

Type 2 diabetes in Mexican workers exposed to a potential source ofdioxins in the cement industry determined by a job exposure matrix / Diabetes tipo 2 en trabajadores Mexicanos expuestos a una fuente potencial de dioxinas en la industria del cemento determinado a través de una matriz de exposición ocupacional

Purpose: To identify association between type 2 diabetes (DM2) with occupational exposure to potential dioxins source in Mexican cement industry workers. Materials and Methods: 56 medical files of cement industry workers with diagnosis of DM2 were included; 56 medical files of workers from the same industry without DM2 were the controls. The daily dose of exposure (DDE) to the potential dioxins source per work years was estimated by a job exposure matrix and categorized as low, moderate, and high. Logistic regression model that correlated high exposure to potential source of dioxins (cement clinker confinement) per work years and presence of DM2 was adjusted by work seniority, patient age at which DM2 diagnosis was established and DM2 familiar background. Results: the OR for the presence of DM2 in workers with moderate and high exposure to potential source of dioxins in the cement industry was 3.25 (1.10–9.57), p= 0.03, adjusted by work seniority, workerage at which DM2 diagnosis was established, and DM2 familiar background.Conclusions: In according with the data explored in the medical files of cement industry workers,there is an association between high exposure to the industrial confinement of the cement clinker as apotential source of dioxins and presence of DM2 in a modest dose-response gradient (AU)

Propósito: Identificar asociación entre diabetes tipo 2 (DM2) en trabajadores Mexicanos con la exposición ocupacional a una fuente potencial de dioxinas de la industria cementera.Material y métodos: Se incluyeron 56 expedientes clínicos de trabajadores de la industria cementera con diagnóstico de DM2; los controles lo constituyeron 56 expedientes clínicos de trabajadores de la misma industria pero sin DM2. La dosis diaria de exposición (DDE) a la fuente potencial de dioxinas por años trabajados se estimó a través de una matriz de exposición ocupacional y fue categorizada como baja,moderada y alta. El modelo de regresión logística que correlacionó la alta exposición a la fuente potencial de dioxinas (confinamiento de la escoria o clinker de cemento) por años trabajados y presencia de DM2 fue ajustada por antigüedad en el trabajo, la edad del paciente en la que se estableció el diagnóstico de DM2 y antecedente familiar de DM2.Resultados: la razón de momios para la presencia de DM2 en trabajadores con exposición moderada y alta a la fuente potencial de dioxinas en la industria cementera fue de 3.25 (1.10–9.57), p= 0.03, ajustada por antigüedad en el trabajo, edad del trabajador en la que se estableció el diagnóstico de DM2, y el antecedente familiar de DM2.Conclusiones: De acuerdo con los datos explorados en los expedientes clínicos de trabajadores de la industria cementera, existe asociación entre la alta exposición al confinamiento industrial de la escoria oclinker de cemento, como fuente potencial a dioxinas, y la presencia de DM2 con un modesto gradiente de dosis-respuesta (AU)

The relationship among mental health status (GHQ-12), health related quality of life (EQ-5D) and health-state utilities in a general population.

AIM: To assess the relationship between mental health and health-related quality of life (HRQL) in the general population, and to map GHQ-12 as a screening test for population psychological distress to a generic health state measure (EQ-5D) in order to estimate health state values and allow deriving quality-adjusted life years. METHODS: Relationship between mental health and HRQL was examined from the 2004 Canary Islands' Health Survey. Participants were classified as probable psychiatric cases according to GHQ-12. HRQL was measured by the EQ-5D index. Multivariate lineal regression analysis was used to examine the association between mental health and HRQL adjusting by socio-demographic variables and comorbidities. A multivariate regression model was built from EQ-5D to estimate health states values using GHQ-12 as exposure. RESULTS: EQ-5D index scores decreased as the GHQ-12 scores increased. Clinical and socio-demographic factors influenced HRQL without changing the overall trend for this negative relationship. The regression equation explained 43% of the variance. For estimation of utility scores, the model showed a high predictive capacity, with a mean forecast errors of 16%. CONCLUSIONS: HRQL progressively decreased when the probability of being a psychiatric case increased. Findings enable health state values to be derived from GHQ-12 scores for populations where utilities has not or cannot be measured directly.

Association between appropriate use of transfusion in children and in-hospital mortality: a Venezuelan prospective cohort study

Los riesgos de la transfusión han sido estudiados extensamente; sin embargo, información relacionada con el uso apropiado de la transfusión en pediatría y mortalidad intra-hospitalaria se desconoce. El objetivo fue determinar la asociación entre el uso apropiado de transfusión en pediatría y la mortalidad intra-hospitalaria. Se diseño una cohorte prospectiva. Para evaluar el uso apropiado se utilizaron los criterios de la “American Association of Blood Bank Pediatric Hemotherapy”. Se realizó en el Hospital Infantil “Dr. Jorge Lizarraga”, Valencia, Venezuela, entre enero 2002 y septiembre de 2003. El principal desenlace fue muerte durante la hospitalización. 617 paicnetes (< 15 años, masculinos = 57 por ciento) fueron evaluados. El uso apropiado fue 81.2 por ciento (501/617). En el grupo de transfusión no apropiada, la tasa de incidencia (TI) de mortalidad fue 7 por 1000, mientras que en el grupo de transfusión apropiada la TI fue 3,6 por 1000. La razón de TI fue 1,98 (IC95 por ciento = 1,1 a 3,6, p = 0,01). El hazard ratio (HR) crudo fue 2 (IC95 por ciento = 1,2 a 3,5 p = 0,01). Al analizar el efecto del uso no apropiado sobre la mortalidad en los distintos grupos de edad, hubo un mayor efecto en los mayores de 1 año (HR=4,4, IC95 por ciento= 1,39 to 13,6 p = 0,01) comparado con el efecto en los menores de 1 año (HR= 1,5 IC95 por ciento= 0,79 to 2,9, p = 0,2). La transfusión inapropiada de pacientes pediátricos hospitalizados se asocia con un incremento de riesgo de muerte. Todo esfuerzo educacional sobre el uso apropiado de la transfusión es loable. Se requieren más estudios que evalúen la asociación entre la transfusión y mortalidad

¿Existe asociación entre el virus de la Hepatitis B y el carcinoma hepatocelular?: Cómo demostrarlo mediante gastroenterología basada en la evidencia

En la generación de evidencias que surgen del seguimiento de pacientes, obtenidas a partir de los estudios epidemiológicos, el riesgo relativo (RR) y el riesgo absoluto (RA) son expresiones que se utilizan para cuantificar la asociación entre un factor de exposición y un evento de salud. Sendas expresiones son de variables dicotómicas. Permiten establecer la intensidad y la dirección de la asociación a través de la obtención de la probabilidad de ocurrencia del evento para cada nivel del factor de exposición. El cálculo, su interpretación y sus aplicaciones son ejemplificados.

In epidemiology, relative risk and absolute risk are expressions of measuring of the association between binary variables. In a direct way, they allow to settle down, the intensity of the relationship and to describe the probability of damage for the exposure variable. Their applications are described.

Appropiate use of blood products in pediatric patients in a Venezuelan General University Hospital: cross-sectional study

La transfusión es una tecnología asociada con un elevado costo económico; es necesario para garantizar su seguridad para reducir el riesgo de enfermedades asociadas con la transfusión. No existen estudios que hayan evaluado el uso apropiado de los componentes sanguíneos en población pediátrica. El objetivo fue determinar la prevalencia del uso apropiado de componentes sanguíneos en pediatría. Utilizando los criterios de Asociación Americana de Bancos de Sangre, se realizó un estudio de corte transversal, en la Ciudad Hospitalaria "Dr. Enrique Tejera", principal hospital universitario de Valencia, Venezuela. Se estudiaron pacientes (n=404) hospitalizados en los servicios de medicina, cirugía, emergencia, recién nacidos enfermos, retén de prematuros y cuidados intensivos. El principal desenlace evaluado fue el uso apropiado de la sangre total y de los componentes sanguíneos. La prevalencia (PV) global del uso apropiado fue 60,49 por ciento; por Departamentos fue 87,8 por ciento en Medicina, 47,4 por ciento en Cirugía, 65 por ciento en Emergencia, 55,4 por ciento en Recién Nacidos Patológicos, 44 por ciento en Retén de Prematuros, 51,1 por ciento Retén de Recién Nacidos y 81,3 por ciento en Unidad de Cuidados Intensivos. La PV del uso apropiado por hemoderivado fue 76 por ciento para concentrado de glóbulos rojos, 83 por ciento para sangre total, 52,6 por ciento para plaquetas, 38,3 por ciento para plasma fresco congelado y 28,6 por ciento para crioprecipitado. Las principales conclusiones del estudio son: 1) La prevalencia del uso apropiado de los componentes fue de 60,9 por ciento, 2) Existe alto riesgo de uso inapropiado de concentrado de plaquetas, plasma fresco congelado y crioprecipitado y 3) Los servicios de Medicina y Cuidados Intensivos poseen alta prevalencia (>80 por ciento) de uso apropiado de transfusiones

Prematurity and maternal folate deficiency: anemia during pregnancy study group results in Valencia, Venezuela.

The purpose of this study was to determine the association and its magnitude between prematurity and folate deficiency in women in their third trimester of pregnancy, and at labor. An incident case-control study was conducted using 2 controls per case. Data was obtained in a tertiary hospital in Valencia, Venezuela. A total of 543 women who delivered between May and December 1996 entered into the study. Women having a preterm delivery (< 37 weeks of gestation at delivery) were defined as cases (n = 181). Anemia was defined according to WHO as Hb less than 11 g/dL, when a pregnant woman had a folate serum level < 3 microg/ml was considered a folate deficiency. Logistic regression was used to analyze the data and likelihood ratio test was done for model comparison. Folate deficiency was found to be significantly associated with prematurity (Odds Ratio: 1.97; 95%CI = 1.06 to 3.68 P = .032), after adjusting for prior preterm labor, prenatal care visits, prior abortion, prior fetal death, placental abruption, and premature rupture oval membranes. In conclusion, maternal folate deficiency at the end of the third trimester of pregnancy, at labor, was associated with an increased risk of prematurity.