[The impact on sample sizes of studies if the significance level is changed from an α of 0.05 to 0.005]. / Impacto sobre el tamaño de las muestras en estudios nacionales si cambiara el nivel de significación estadística de α= 0,05 a α = 0,005.

BACKGROUND: The statistical significance α = 0.05 is the cut-off point used to decide whether a hypothesis is statistically significant. When p-value is less than 0.05, we reject the null hypothesis. Although this criterion has been used for almost a century to generate new knowledge, there is currently an international discussion about the need to decrease the significance to α = 0.005. AIM: To determine the effects that changing the p value would have on the sample size of different types of studies. MATERIAL AND METHODS: A series of formulas for calculating the sample size of cross-sectional and comparative studies were used to create case scenarios. RESULTS: By changing α = 0.05 to α = 0.005, the sample sizes in cross-sectional studies would double and in comparative studies would increase between 60% and 70%, depending on the statistical power chosen. CONCLUSIONS: Considering the sample size implications, the change in the level of significance would have important effects on the Chilean science. The cost of a randomized clinical trial could increase by at least 27% to 32%. This increase could be similar for cross-sectional studies. With an investment of less than 0.4% of gross domestic product in science and technology, national scientific research would become more expensive, distributing the few available resources among fewer projects. This effect should be considered in any discussion about national budget for science and technology.

Relationship between physical fitness and academic achievement in Chilean schoolchildren of 8th grade. / Condición física de escolares chilenos de 8° año básico y su relación con el rendimiento académico.

INTRODUCTION: Good physical fitness (PF) is related, among many benefits, to functional and structu ral brain changes that favor learning. OBJECTIVE: To analyze the association between PF and academic performance (AP) in Chilean schoolchildren according to sex, and to determine if the kind of school dependency influences this association. SUBJECTS AND METHOD: Cross-sectional study analyzing po pulation data of 8th-grade students evaluated by the SIMCE-2011 test. The sample included only 13 and 14 years old students, of both sexes, with all PF and AP tests taken. The results of PF and AP tests were categorized as poor, regular, and good. A binary logistic regression was performed explaining a good AP from the PF categories according to sex, and kind of school dependency, adjusting for age, nutritional status, parents' educational level, and school socioeconomic level. RESULTS: Out of 19,929 records, 12,338 schoolchildren were considered, where 47.9% were female. 33.4% of girls and 49.5% of boys presented good PF, and 16.9% and 21.5% presented good AP respectively. Schoolchildren with good PF had more chances of achieving good AP than those with poor PF (girls 84% and boys 78%, both p < 0.001). Considering the kind of school dependency, good PF in girls attending public schools increased the chances of achieving good AP by 334% (p < 0.001) and in boys attending sub sidized private schools by 91% (p = 0.01). CONCLUSION: Both girls and boys with good PF have more chances of achieving a good AP. By including the kind of school dependency, the association persists in girls attending public schools and boys attending subsidized private schools.

Band ligation versus beta-blockers for primary prophylaxis of oesophageal variceal bleeding in children with chronic liver disease or portal vein thrombosis.

BACKGROUND: Portal hypertension commonly accompanies advanced liver disease and often gives rise to life-threatening complications, including haemorrhage from oesophageal and gastrointestinal varices. Variceal haemorrhage commonly occurs in children with chronic liver disease or portal vein obstruction. Prevention is therefore important. Following numerous randomised clinical trials demonstrating efficacy of non-selective beta-blockers and endoscopic variceal ligation in decreasing the incidence of variceal haemorrhage, primary prophylaxis of variceal haemorrhage in adults has become the established standard of care. Hence, band ligation and beta-blockers have been proposed to be used as primary prophylaxis of oesophageal variceal bleeding in children. OBJECTIVES: To determine the benefits and harms of band ligation compared with any type of beta-blocker for primary prophylaxis of oesophageal variceal bleeding in children with chronic liver disease or portal vein thrombosis. SEARCH METHODS: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (February 2019), CENTRAL (December 2018), PubMed (December 2018), Embase Ovid (December 2018), LILACS (Bireme; January 2019), and Science Citation Index Expanded (Web of Science; December 2018). We scrutinised the reference lists of the retrieved publications and performed a manual search from the main paediatric gastroenterology and hepatology conferences (NASPGHAN and ESPGHAN) abstract books from 2009 to 2018. We searched ClinicalTrials.gov for ongoing clinical trials. There were no language or document type restrictions. SELECTION CRITERIA: We planned to include randomised clinical trials irrespective of blinding, language, or publication status for assessment of benefits and harms. We planned to also include quasi-randomised and other observational studies retrieved with the searches for randomised clinical trials for report of harm. DATA COLLECTION AND ANALYSIS: We planned to summarise data from randomised clinical trials using standard Cochrane methodologies. MAIN RESULTS: We found no randomised clinical trials assessing band ligation versus beta-blockers for primary prophylaxis of oesophageal variceal bleeding in children with chronic liver disease or portal vein thrombosis. AUTHORS' CONCLUSIONS: Randomised clinical trials assessing the benefits or harms of band ligation versus beta-blockers for primary prophylaxis of oesophageal variceal bleeding in children with chronic liver disease or portal vein thrombosis are lacking. There is a need for well-designed, adequately powered randomised clinical trials to assess the benefits and harms of band ligation versus beta-blockers for primary prophylaxis of oesophageal variceal bleeding in children with chronic liver disease or portal vein thrombosis. Those randomised clinical trials should include patient-relevant clinical outcomes such as mortality, failure to control bleeding, and adverse events.

Spirometric values in healthy preschool children. / Valores espirométricos en pre-escolares sanos.

INTRODUCTION: Spirometry is the most commonly used test to evaluate lung function. Foreign refe rence standards are currently available for preschool children. OBJECTIVES: 1. To measure spirometric variables in healthy Chilean preschool children, 2. To compare these results with predictive ones according to GLI (Global Lung Initiative), Eigen (USA) and França (Brazil), and 3. If there is a sig nificant difference with these, to develop reference equations. SUBJECTS AND METHOD: Questionnaires were distributed to parents in several schools and kindergartens in Santiago. Children with a history of prematurity, asthmatic symptoms, chronic lung disease (including asthma), and chronic non respiratory disease were excluded. Spirometry was performed according to ATS/ERS 2007 guideli nes, with MedGraphics equipment, USA. Family and environmental background, weight and height were recorded, as well as values obtained in forced vital capacity (FVC), forced expiratory volume in 0.5, 0.75 and 1 second (FEV0.5, FEV0.75, and FEV1, respectively). RESULTS: 276 spirometries were performed, 202 met acceptability criteria, 112 girls, average age 5.01 ± 0.57 years, height 108.7 ± 5.6 cm. When comparing by gender, there was only a significant difference in FVC, which was higher in boys. The average values obtained in the total group were: FVC 1.22 ± 0.22 liters, FEV1 1.16 ± 0.18 liters, FEV0.75 1.07 ± 0.17 liters. These parameters were higher in percentage than the predictive ones according to GLI, Eigen, and França, except FVC with Eigen, therefore, predictive equations were de veloped. CONCLUSIONS: Spirometric values of preschoolers living in Santiago were higher than foreign reference values. We proposed these reference standards to be used in our country.

[Cardiometabolic risk in children with severe obesity]. / Riesgo cardiometabólico en niños con obesidad grave.

Introduction: Introduction: severe obesity has had a greater increase than non-severe obesity in Chilean schoolchildren during the last years. We do not know whether the cut-off point currently used to define severe obesity in children (BMI ≥ + 3 DE, WHO-2007 curves) is associated with a greater biological risk in our population. Objective: to describe and compare cardiometabolic risk in schoolchildren with severe vs. non-severe obesity. Methods: a secondary analysis of a sample of 3,325 schoolchildren was performed, in which cardiometabolic risk factors were studied. The prevalence of these was compared in the subsample of 589 schoolchildren with obesity according to whether it was severe or not, and the respective ORs were calculated. Results: mean age was 11.4 ± 0.98 years, 46 % were girls, and 11.5 % of the sample had severe obesity, with a higher prevalence of most of the factors studied and no differences in chronic disease, obesity or education in parents, or physical activity of the child. The risk of those with severe obesity for central obesity, insulin resistance, high blood pressure, and metabolic syndrome reached an OR of 12.9, 3.2, 2.67, and 1.92, respectively, as compared to those with non-severe obesity. Conclusion: this definition of severe obesity in childhood favors the identification of children with higher cardiometabolic comorbidity, which allows to focus the efforts of secondary prevention and its most timely treatment.

Introducción: Introducción: la obesidad grave ha tenido un mayor aumento que la obesidad no grave en los escolares chilenos durante los últimos años. Desconocemos si el punto de corte actualmente utilizado para definir la obesidad grave (IMC ≥ + 3 DE, curvas OMS-2007) se asocia a un mayor daño biológico en nuestra población pediátrica. Objetivo: describir y comparar el riesgo cardiometabólico en escolares con obesidad grave y no grave. Método: se realizó un análisis secundario de una muestra de 3325 escolares en los que se estudiaron los factores de riesgo cardiometabólico. Se comparó la prevalencia de estos factores en los que presentaban obesidad según fuera esta grave o no, calculándose los OR respectivos. Resultados: de los 589 sujetos con obesidad, con una media de edad de 11,4 ± 0,98 años, el 46 % eran de género femenino y el 11,5 % presentaban obesidad grave, con mayor prevalencia de la mayoría de los factores estudiados y sin diferencias en cuanto a antecedentes parentales de enfermedad crónica u obesidad, educación de los padres y actividad física del niño. Los niños con obesidad grave tenían un mayor riesgo de obesidad central (OR: 12,9), resistencia insulínica (OR: 3,2), HTA (OR: 2,67) y síndrome metabólico (OR:1,92). Conclusión: esta definición de obesidad grave en la niñez favorece la identificación de los niños con mayor comorbilidad cardiometabólica, lo cual permite focalizar los esfuerzos de prevención secundaria y su tratamiento más oportuno.

Impacto sobre el tamaño de las muestras en estudios nacionales si cambiara el nivel de significación estadística de de α= 0.05 a α = 0.005 / The impact on sample sizes of studies if the significance level is changed from an α of 0.05 to 0.005

BACKGROUND: The statistical significance α = 0.05 is the cut-off point used to decide whether a hypothesis is statistically significant. When p-value is less than 0.05, we reject the null hypothesis. Although this criterion has been used for almost a century to generate new knowledge, there is currently an international discussion about the need to decrease the significance to α = 0.005. AIM: To determine the effects that changing the p value would have on the sample size of different types of studies. Material and Methods: A series of formulas for calculating the sample size of cross-sectional and comparative studies were used to create case scenarios. RESULTS: By changing α = 0.05 to α = 0.005, the sample sizes in cross-sectional studies would double and in comparative studies would increase between 60% and 70%, depending on the statistical power chosen. Conclusions: Considering the sample size implications, the change in the level of significance would have important effects on the Chilean science. The cost of a randomized clinical trial could increase by at least 27% to 32%. This increase could be similar for cross-sectional studies. With an investment of less than 0.4% of gross domestic product in science and technology, national scientific research would become more expensive, distributing the few available resources among fewer projects. This effect should be considered in any discussion about national budget for science and technology.

Condición física de escolares chilenos de 8° año básico y su relación con el rendimiento académico / Relationship between physical fitness and academic achievement in Chilean schoolchildren of 8th grade

Resumen: Introducción: Una buena condición física (CF) se relaciona, entre muchos beneficios, a modifica ciones funcionales y estructurales cerebrales que favorecen el aprendizaje. Objetivo: Analizar la aso ciación entre CF y rendimiento académico (RA) en escolares chilenos según sexo y determinar si la dependencia administrativa de la escuela influye en dicha asociación. Sujetos y Método: Estudio transversal sobre datos poblacionales de escolares de 8° básico evaluados por SIMCE-2011. La mues tra incluyó solo escolares de 13 y 14 años, de ambos sexos, con todas las pruebas de CF y RA rendidas. Los resultados de CF y RA fueron categorizados en malo, regular y bueno. Se realizó una regresión logística binaria explicando un buen RA a partir de las categorías de CF según sexo y dependencia administrativa, ajustando por edad, estado nutricional, nivel educacional de los padres y nivel so cioeconómico de la escuela. Resultados: De 19.929 registros se consideraron 12.338 escolares donde 47,9% fueron mujeres. Presentaron buena CF 33,4% de las mujeres y 49,5% de los hombres, y buen RA 16,9% y 21,5%, respectivamente. Escolares con buena CF presentaron más chances de alcanzar buen RA que escolares con mala CF (mujeres: 84% y hombres 78% más; p < 0,001). Considerando la dependencia administrativa, buena CF en mujeres de colegios municipales aumentó las posibilidades en 334% (p < 0,001) y en hombres de colegios particulares subvencionados, en 91% (p = 0,01). Con clusión: Tanto mujeres como hombres con buena CF tienen más posibilidades de alcanzar un buen RA. Al incluir la dependencia administrativa la asociación persiste en mujeres de colegios municipa les y en hombres de colegios particulares subvencionados.

Abstract: Introduction: Good physical fitness (PF) is related, among many benefits, to functional and structu ral brain changes that favor learning. Objective: To analyze the association between PF and academic performance (AP) in Chilean schoolchildren according to sex, and to determine if the kind of school dependency influences this association. Subjects and Method: Cross-sectional study analyzing po pulation data of 8th-grade students evaluated by the SIMCE-2011 test. The sample included only 13 and 14 years old students, of both sexes, with all PF and AP tests taken. The results of PF and AP tests were categorized as poor, regular, and good. A binary logistic regression was performed explaining a good AP from the PF categories according to sex, and kind of school dependency, adjusting for age, nutritional status, parents' educational level, and school socioeconomic level. Results: Out of 19,929 records, 12,338 schoolchildren were considered, where 47.9% were female. 33.4% of girls and 49.5% of boys presented good PF, and 16.9% and 21.5% presented good AP respectively. Schoolchildren with good PF had more chances of achieving good AP than those with poor PF (girls 84% and boys 78%, both p < 0.001). Considering the kind of school dependency, good PF in girls attending public schools increased the chances of achieving good AP by 334% (p < 0.001) and in boys attending sub sidized private schools by 91% (p = 0.01). Conclusion: Both girls and boys with good PF have more chances of achieving a good AP. By including the kind of school dependency, the association persists in girls attending public schools and boys attending subsidized private schools.

[Dyslipidemias in school-age chilean children: prevalence and associated factors]. / DISLIPIDEMIAS EN ESCOLARES CHILENOS: PREVALENCIA Y FACTORES ASOCIADOS.

INTRODUCTION: Dyslipidemias are a key cardiovascular risk factor, and are increased since early childhood. The objective of this study was to describe the prevalence, characteristics of dyslipidemias and associated factors in a population of Chilean children. METHODS: Cross-sectional study done in school-age children from Santiago, Chile (2009-2011). Parents answered questions about family medical history and children answered questions about physical activity. Anthropometry was performed and in a blood sample (12 hours fast) lipid profile, glycemia and insulinemia were measured. RESULTS: We recruited 2900 euglycemic children, 11.4 ± 0.97 years old, 52% girls. According to BMI, 22.5% were overweight and 15,3% had obesity. Considering recommended cut-off points for lipids, 69.3% were in acceptable range, 19.2% at risk and 11.5% at high cardiovascular risk. In total, 32% of the population had any clinical form of dyslipidemia: Isolated hypertriglyceridemia (9.4%), low HDL-C (7.6%), isolated hypercholesterolemia (4.9%), atherogenic dyslipidemia (6.24%) and mixed dyslipidemia (3.9%). Except for isolated hypercholesterolemia, dyslipidemias were more frequent in girls (globally 36.2% vs. 27.4%, p<0.0001). Low HDL-C was associated with sedentary lifestyle. In multiple logistic regression analysis, nutritional status was the most important associated factor, with less influence of age, sex, central obesity, insulin resistance and history of parental cardiovascular risk factors. CONCLUSIONS: In this population of Chilean school-age children, we found a high prevalence of dyslipidemia, and the principal determinant was weight excess.

Introducción: Las dislipidemias son un factor de riesgo cardiovascular clave, en aumento ya desde la niñez. El objetivo de este estudio fue describir la prevalencia, tipo de dislipidemias y factores asociados, en una población de niños chilenos. Métodos: Estudio transversal en escolares de Santiago de Chile (2009-2011). Se realizó antropometría, encuesta de antecedentes familiares a los padres y de actividad física a los niños. En muestra sanguínea de ayunas se midió perfil lipídico, glicemia e insulinemia. Resultados: Se reclutaron 2900 escolares de 11,42±0,97 años de edad, 52% mujeres, todos euglicémicos. Según IMC, 22,5% tenía sobrepeso y 15,3% obesidad. Al considerar los límites recomendados para cada lípido, 69,3% se encontraba en rango aceptable, 19,2% en riesgo y 11,5% en alto riesgo cardiovascular. En total, 32% de la población presentó alguna forma clínica de dislipidemia: Hipertrigliceridemia aislada (9,4%), Bajo C-HDL (7,6%), Hipercolesterolemia aislada (4,9%), Dislipidemia aterogénica (6,24%) y Dislipidemia mixta (3,9%). Excepto la hipercolesterolemia aislada, las demás dislipidemias fueron más frecuentes en las niñas (36,2% vs. 27,4%, p.

[EFFECT OF EARLY PROTEIN-CALORIE MALNUTRITION ON NUTRITIONAL STATUS AND ATTRIBUTES OF THE METABOLIC SYNDROME IN YOUNG ADULTS]. / EFECTOS DE LA DESNUTRICIÓN CALÓRICO-PROTEICA TEMPRANA EN EL ESTADO NUTRICIONAL Y ATRIBUTOS DEL SÍNDROME METABÓLICO EN UNA COHORTE DE ADULTOS JÓVENES.

BACKGROUND: during recent years consistent studies have characterized the relationship between moderate and severe protein-calorie malnutrition and the appearance of non-communicable diseases in adulthood like metabolic syndrome (MS). AIM: to analyze the relationship between moderate and severe protein-calorie malnutrition during the first 1 000 days of life and the MS in a cohort of adults from Curicó, Chile. MATERIAL AND METHODS: we studied 49 young adults who had suffered moderate to severe protein-calorie malnutrition during their first two years of life. Anthropometry, blood pressure measurement and laboratory tests were performed, and the burden of MS attributes was determined. RESULTS: the prevalence of MS was 14.3% with no significant differences by gender, showing a direct and significant association between burden of MS and body mass index, waist / height index, blood pressure, plasma levels of glucose and triglyceride, and an inverse association with HDL. CONCLUSION: systolic blood pressure and plasma level of triglyceride represented the most important risk factors for SM in this cohort. We found no association between the presence of protein-calorie malnutrition and MS.

Introducción: estudios consistentes durante los últimos años han caracterizado la relación entre la desnutrición calórico-proteica (DCP) y el desarrollo de enfermedades no transmisibles en la adultez, como el Síndrome Metabólico (SM). Objetivo: analizar la relación entre SM en la adultez y la DCP durante los primeros 1.000 días de vida en una cohorte de adultos recientemente generada en Curicó, Chile. Material y métodos: se analizaron 49 sujetos adultos jóvenes que durante sus primeros dos años de vida sufrieron desnutrición calórico-proteica moderada a severa mediante la realización de antropometría, medición de la presión arterial y exámenes de laboratorio. Se determinó la prevalencia del SM y la carga de sus atributos. Resultados: se obtuvo una prevalencia de SM del 14,3% sin diferencias significativas por género, con una asociación directa y notable entre la carga de SM, el índice de masa corporal (IMC), el índice cintura/talla, presión arterial y niveles plasmáticos de glicemia y triglicéridos (TG), y una asociación inversa con colesterol HDL. Conclusión: la presión arterial sistólica y el valor plasmático de TG representaron los factores de riesgo más importantes del SM en esta cohorte. No se encontró asociación entre la DCP en los 1.000 primeros días de vida y el SM en la adultez.

Valores espirométricos en pre-escolares sanos / Spirometric values in healthy preschool children

INTRODUCCIÓN: La espirometría es el examen más utilizado para evaluar función pulmonar. Para niños pre-escolares actualmente se cuenta con patrones de referencia extranjeros. OBJETIVOS: 1. Medir variables espirométricas en pre-escolares chilenos sanos, 2. Comparar estos resultados con predictivos según GLI (Global Lung Initiative), Eigen (USA) y França (Brasil) y 3. De haber diferencia significativa con éstos, elaborar ecuaciones de referencia. SUJETOS Y MÉTODO: Se distribuyeron encuestas a apoderados de colegios y jardines infantiles de Santiago. Se excluyeron niños con antecedente de prematurez, síntomas asmáticos, enfermedad pulmonar crónica (incluida asma) y enfermedad crónica no respiratoria. La espirometría se realizó según guías ATS/ERS 2007, con equipo MedGraphics, USA. Se registraron antecedentes familiares, ambientales, peso y talla y los valores obtenidos en capacidad vital forzada (CVF), volumen espirado forzado en 0,5, 0,75 y 1 segundo (VEF 05, VEF0 75 y VEFj, respectivamente). RESULTADOS: Se realizaron 276 espirometrías, de las cuales 202 cumplieron criterios de aceptabilidad, 112 mujeres, edad promedio 5,01 ± 0,57 años, talla 108,7 ± 5,6 cm. Al comparar por género, solo hubo diferencia significativa en CVF, siendo superior en hombres. Los valores promedio obtenidos en el grupo total fueron: CVF 1,22 ± 0,22 litros, VEF1 1,16 ± 0,18 litros, VEF075 1,07 ± 0,17 litros. Nuestros parámetros fueron porcentualmente mayores que los predictivos según GLI, Eigen y França, excepto CVF con Eigen, motivo por el cual se construyeron ecuaciones predictivas. CONCLUSIONES: Los valores espirométricos de pre-escolares residentes en Santiago fueron superiores a los valores de referencia extranjeros. Se proponen patrones de referencia que podrían ser utilizados en nuestro medio.

INTRODUCTION: Spirometry is the most commonly used test to evaluate lung function. Foreign refe rence standards are currently available for preschool children. OBJECTIVES: 1. To measure spirometric variables in healthy Chilean preschool children, 2. To compare these results with predictive ones according to GLI (Global Lung Initiative), Eigen (USA) and França (Brazil), and 3. If there is a sig nificant difference with these, to develop reference equations. SUBJECTS AND METHOD: Questionnaires were distributed to parents in several schools and kindergartens in Santiago. Children with a history of prematurity, asthmatic symptoms, chronic lung disease (including asthma), and chronic non respiratory disease were excluded. Spirometry was performed according to ATS/ERS 2007 guideli nes, with MedGraphics equipment, USA. Family and environmental background, weight and height were recorded, as well as values obtained in forced vital capacity (FVC), forced expiratory volume in 0.5, 0.75 and 1 second (FEV0.5, FEV0.75, and FEV1, respectively). RESULTS: 276 spirometries were performed, 202 met acceptability criteria, 112 girls, average age 5.01 ± 0.57 years, height 108.7 ± 5.6 cm. When comparing by gender, there was only a significant difference in FVC, which was higher in boys. The average values obtained in the total group were: FVC 1.22 ± 0.22 liters, FEV1 1.16 ± 0.18 liters, FEV0.75 1.07 ± 0.17 liters. These parameters were higher in percentage than the predictive ones according to GLI, Eigen, and França, except FVC with Eigen, therefore, predictive equations were de veloped. CONCLUSIONS: Spirometric values of preschoolers living in Santiago were higher than foreign reference values. We proposed these reference standards to be used in our country.

Modelo de asistencia integral del parto: concepto de integralidad basado en la calidad y seguridad / Comprehensive delivery care model: concept of comprehensiveness based on quality and safety

RESUMEN Introducción: A nivel internacional existe un interés por disminuir el uso excesivo de tecnologías durante el parto, inclinándose hacia el desarrollo de modelos de atención personalizados y respetuosos. Chile concentra una de las tasas de cesáreas más altas en la región, muchas de ellas sin justificación clínica. En este contexto, un proyecto FONDEF desarrolló y probó un modelo de asistencia integral del parto (MASIP), considerando la participación activa de la mujer y familia y menos intervenciones innecesarias. Objetivo: evaluar la efectividad de MASIP en comparación con el cuidado estándar del parto. Metodología: A través de un diseño experimental aleatorizado y controlado, se compararon los resultados de calidad y seguridad de MASIP con la modalidad habitual de asistencia del sistema público en Santiago de Chile, para la población de embarazadas de bajo riesgo. Resultados: MASIP resultó ser más efectiva que la asistencia tradicional en términos de calidad con los indicadores de bienestar materno, disminución de medidas de conducción y de atención de parto innecesarias. La frecuencia de cesárea disminuyó durante el período del estudio en ambos grupos, en comparación con un registro histórico de la misma población. En términos de seguridad, los indicadores mantuvieron el estándar alcanzado en las últimas décadas en ambas modalidades, pese a que el modelo integral se caracteriza por tener menos intervención. Conclusión: MASIP es un modelo seguro y de mejor calidad para mujeres de bajo riesgo del sistema público de Chile que el cuidado estándar. Intervenciones futuras para mejorar la experiencia de las mujeres y familias, deben incluir en su diseño los componentes de MASIP.

ABSTRACT Introduction: Worldwide there is a need to reduce the use of excessive technology during childbirth. Consequently, there is an interest to develop respectful and personalized models of care. Chile has one of the highest C-section rates in the region, many of which are not needed. A FONDEF project developed and tested a comprehensive health care model in childbirth (MASIP), considering active participation of women and families and less unneeded clinical interventions. Objective: to evaluate the effectiveness of MASIP in comparison with standard care. Methods: a randomized controlled experiment was conducted in one public hospital in Santiago Chile. Two arms were compared: MASIP vs. standard care. Low obstetric risk women were included. Variables of interest included quality and safety measures. Results: MASIP had better quality results, such as maternal wellbeing and less clinical interventions. During the study c-section was lower in both arms in comparison to a historical record of the same population. Safety outcomes were similar in both arms. Conclusion: MASIP is as safe as the standard care but it has better quality of care. Interventions to improve users' satisfaction and experience should consider the components of MASIP.

[Hospital costs associated with delirium in older medical patients]. / Coste hospitalario asociado al delirium en pacientes mayores.

INTRODUCTION: Delirium is a common and serious complication in older patients, associated with increased, potentially preventable, morbidity and mortality. The aim of this study was to evaluate the associated costs of delirium during hospitalization in a university affiliated hospital in Chile. MATERIALS AND METHODS: Prospective cohort study of consecutive patients 65 years and older, admitted to a medical ward. A psychogeriatric team assessed patients during the first and every 48h until discharge using the Confusion Assessment Method (CAM-S), length of hospital stay, pharmacy and total hospitalization costs were analyzed. Statistical analysis was performed using bivariate and multivariate analysis according to delirium diagnosis. RESULTS: Data from 454 patients was analyzed, 160 of them in a delirium cohort (35.2%) and 294 in a non-delirium cohort (64.8%). The delirium cohort had a longer hospital stay (DATA) and higher mortality (7.0% versus 1.7%). The median of total costs of delirium during hospital stay was 38.7% higher than the non-delirium cohort (P<.001). Total costs were significantly higher in the delirium cohort after adjustment of covariables (P=.01). CONCLUSIONS: This study confirms that delirium is associated with significantly greater costs. Considering that effective delirium prevention is possible, the knowledge of associated costs can help health care providers to justify prevention strategies and finally give better care for older patients.

[Birth rates and reproductive risk in adolescents in Chile, 1990-1999]. / Natalidad y riesgo reproductivo en adolescentes de Chile, 1990-1999.

OBJECTIVE: For Chilean teenage mothers under 15 years old and from 15 to 19 years old, to evaluate the trends in birth rates and reproductive risk for the period of 1990-1999. METHODS: A database was constructed using data from the Demography Yearbook (Anuario de demografía) volumes published by Chile's National Institute of Statistics (Instituto Nacional de Estadísticas) for 1990-1999. From that database we calculated the trends in the number of live births and in the rates of maternal mortality, late fetal mortality, neonatal mortality, and infant mortality among the teenage mothers under 15 and from 15 to 19 years old. We calculated the risk odds ratio (OR) for both of those age groups in comparison with women from 20 to 34 years old. The groups were compared using Fisher's exact test or the chi-square test, and the analysis of trends in the period studied was carried out with Pearson's correlation, with an alpha level of 0.05. RESULTS: In the period studied, for the teenage mothers under age 15, the respective rates for maternal mortality, late fetal mortality, neonatal mortality, and infant mortality were 41.9 per 100 000 live births, 5.1 per 1 000 live births, 15.2 per 1 000 live births, and 27.4 per 1 000 live births. For the adolescents from 15 to 19 years, the corresponding rates were 19.3, 4.1, 8.1, and 16.6; for the women 20-34 years old, they were 26.8, 5.0, 6.7, and 12.1. The adolescents under 15 had higher risks of maternal mortality (OR = 1.56; 95% confidence interval (CI): 0.50 to 4.31; P = 0.372) and of fetal mortality (OR = 1.02; 95% CI: 0.76 to 1.36; P = 0.890), but those differences were not statistically significant. However, the younger adolescents did have significantly higher risks of neonatal mortality (OR = 2.27; 95% CI: 1.92-2.68; P < 0.0001) and of infant mortality (OR = 2.39; 95% CI: 2.04 to 2.62; P < 0.0001). In comparison to the women 20-34 years old, the teenage mothers from 15 to 19 years old had significantly lower risks of maternal mortality (OR = 0.72; 95% CI: 0.56 to 0.92; P < 0.008) and of fetal mortality (OR = 0.81; 95% CI: 0.77 to 0.86; P < 0.0001) but significantly higher risks of neonatal mortality (OR = 1.20; 95% CI: 1.16 to 1.25; P < 0.0001) and of infant mortality (OR = 1.38; 95% CI: 1.35 to 1.42; P < 0.0001). Among both the older teenage mothers and the mothers 20-34 years old there was a significant downward trend in maternal, fetal, neonatal, and infant mortality rates in the period studied; in the younger adolescents only neonatal mortality and infant mortality declined significantly. There was a rising trend in the number of live births among the two groups of teenage mothers, but that trend was statistically significant only for the mothers under 15; among mothers 20-34 years old there was a statistically significant downward trend. CONCLUSIONS: In the period studied, the Chilean teenage mothers faced greater reproductive risk than did the women 20-34 years old. The number of live births among teenage mothers tended to rise during the 1990-1999 period, but the change was significant only for the mothers under age 15. These results point to the need to develop programs that improve both sex education and birth control practices starting in early adolescence.

Edad materna avanzada y riesgo reproductivo / Reproductive risk of women over 40 years old

Background: Pregnancy at extreme ages is a risk factor for maternal, perinatal and infantile death. Aim: To assess the obstetric risk of women over 40 years old. Material and methods : The risk of maternal, late fetal, neonatal and infantile deaths and the risk of low birth weight was assessed in women over 40 years old and compared to the risk of women aged 20-34 years. Data was obtained from the 1999 Annual Report of the National Statistics Institute and the odds ratios (OR) with a 95 percent confidence interval were calculated. Results: Women over 40 years had a higher risk of maternal death (OR 7.13, 3.31-14.97), late fetal death (OR 2.19, 1.69-2.85), neonatal death (OR 1.8, 1.4-2.32), infantile death (OR 1.8, 1.49-2.18) and low birth weight (OR 1.72, 1.58-1.88). Conclusions : The higher reproductive risk of women over 40 years is confirmed. Better birth control programs at this age will reduce this risk

Evolución de la natalidad y del riesgo reproductivo en mujeres de 40 años o más años en la década de los 90 / Natality evolution and the reproductive risk in women of 40 years old or older in 90' decade

Se evalúa el riesgo reproductivo en mujeres chilenas de 40 o más años, comparadas con mujeres de 20 a 34 años, en el periodo 1990-1999. El riesgo se evaluó según Odds Ratio con un intervalo de confianza del 95 por ciento. El riesgo de muerte materna (4.05; 3.13-5323), fetal tardía (2.10; 1.94-2.27), neonatal (1.62; 1.50-1.75) e infantil (1.60; 1.51-1.70) fue más alto en las mujeres mayores. En el grupo de estudio, los nacimientos aumentaron significativamente, mientras que en el grupo control el descenso fue significativo. En las mujeres mayores, la tasa de mortalidad materna y neonatal no presentaron cambios significativos, mientras que la tasa de mortalidad fetal tardía e infantil disminuyeron significativamente. Se concluye que el riesgo reproductivo en mujeres de 40 o más años es significativamente mayor que en mujeres menores, y el control de la natalidad es la estrategia básica para reducir los resultados adversos

Epidemiología del traumatismo encefalocraneano en niños del área suroriente de Santiago / Epidemiology of head injuries in children at Santiago's southwest area, Chile

Se estudiaron retrospectivamente las características epidemiológicas del traumatismo encéfalocraneano en 286 pacientes ingresados con ese diagnóstico a un hospital general del Servicio de Salud Metropolitano Sur-Oriente de Santiago de Chile, entre enero 1993 y abril 1995. La edad promedio de los pacientes era 6.1 años, 4,7 por ciento eran varones, 34,5 por ciento escolares (5 a 14 años) 25,2 por ciento preescolares (2 a menos de 5 años) y 20,3 por ciento lactantes (menores de 24 meses). En los lactantes y preescolares el accidente ocurrió con más frecuencia en el hogar (78,6 por ciento y 60 por ciento respectivamente), en escolares en la vía pública (76,7 por ciento), En los primeros la principal causa del traumatismo fueron las caídas, en los escolares los accidentes de tránsito (65,6 por ciento). En 64,9 por ciento de los casos la consulta fue hecha en la primera hora. El estado de la conciencia al ingresar al hospital (escala de coma de Glashow), era 13 a 15 puntos en 76,9 por ciento de los pacientes, 9 a 12 puntos en 10,5 por ciento de ellos e igual o menor a 8 puntos en 10,8 por ciento, proporciones que son mayores que las descritas en otras series

Desempeño académico de los estudiantes de medicina: ¿un resultado predecible? / Academic performance of medical students: a predictable result?

Background: Traditionally, medical schools demand their students a high dedication in time, responsibility and integrity. Aim: To assess the predictive capacity of several specific variables, on the academic performance of medical students. Material and methods: All students who entered during 1984-1995 period were studied. The academeic performance was assessed using two indices: an overall evaluation of successfulness as determined by the approval rate in different courses and grade-point average obtained during the first three years at the Medical School. The variables used to predict academic performance were year of enrollment, high school grades, university admission test scores, biomedical and demographic characteristics. All these were meassured at the time when the student was enrolled. Results: Eight hundred and eight students were studied at the end of the third year. The most important predictive variables selected for both performance indices were: high school grades, admission biology test scores, place were high school studies were done, and previous university studies. In addition verbal and mathematics admission academic performance tests scores were selected for grade-point average index. Although, the overall admission score and high school academic performance were significantly associated with the two outcomes, they were not selected in the final models. Conclusions: The best predictors of an optimal academic performance in these medical students were high school grades, admission bilogy test scores, residing in Metropolitan Santiago and previous university studies

Mortalidad neonatal precoz: Chile 1991-1997 / Early neonatal mortality in Chile between 1991-1997

Se analiza la mortalidad neonatal precoz en Chile, entre los años 1991-1997. Los nacidos vivos, la tasa de mortalidad neonatal precoz y del bajo peso al nacer presentaron un descenso significativo. No hubo cambios significativos en las tasas de prematurez y de nacidos de muy bajo peso. La tasa de mortalidad neonatal precoz se correlacionó significativamente con la tasa de bajo peso al nacer. Las tres primeras causas de muerte neonatal precoz son las malformaciones congénitas (32,3 por ciento), los trastornos relacionados con la duración corta de la gestación y el bajo peso al nacer (23,8 por ciento) y el síndrome de dificultad respiratoria (10,1 por ciento). El 55,8 por ciento de las muertes neonatales ocurren antes del primer día de vida, con un descenso significativo en el período estudiado

Predictores de rehospitalización en pacientes con insuficiencia cardíaca congestiva / Predictors of readmission in patients with congestive heart failure

Repeated hospitalizations among patients (pts) with congestive heart failure (CHF) are common. Purpose: This retrospective study was designed to determine predictors of readmission. Methods: Inclusion criteria: admitted to University Hospital with a primary diagnosis of CHF between 10/1/94-9/30/95: lived in Jefferson county. Exclusions: cardiac transplant during study period; major comorbidity (e.g. malignancy, advanced renal failure). Predictors of readmission were determined by stepwise logistic regression analysis and predictor of time to readmission with Cox Proportionate Hazards modeling p<0.05 was considered statistically significant. Results: Mean age of the 237 pts was 66.5 yrs; 56 percent women. Mean left ventricular ejection fraction (LVEF) was 29 percent; 96 percent were in NYHA Class III/IV. Mean length of stay was 5 days; 52 pts (22 percent) had >1 admission. CHF etiologies: Ischemic (42 percent), hypertensive (37 percent), idiopathic (12 percent). Demographic characteristics and insurance status did not predict readmission risk. Predictors of readmission in the logistic and Cox models were similar. Increased risk of readmission was associated with myocardial ischemia (logistic OR 42.7), past NYHA Class III and IV (OR 32.8), plasmatic creatinine at discharge (OR 1.9) and continued smoking (OR 3.26). History of CABG was associated with a decreased risk of rehospitalization (OR 0.12). Beta-blocker use was associated with decreased risk, but did not achieve statistical significance. ACE-I use (prescribed in 78 percent of pts), did not contribute to the model. Diabetes Mellitus and a lower LVEF were more frequent in the readmitted group, but they did not predict readmission. Conclusion: CHF pts who have evidence of ischemia, advanced symptoms, renal dysfunction, and who continue to smoke are at increased risk for hospital readmission. Pts with these characteristics should be identified prior to hospital discharge and considered for intensive outpatient intervention